diff --git a/eslint.config.js b/eslint.config.js
index 4618b64f..041e8fb3 100644
--- a/eslint.config.js
+++ b/eslint.config.js
@@ -35,6 +35,10 @@ module.exports = [
       "no-unused-vars": "error",
       "no-undef": "error",
 
+      // ES6+ modernization - GO TIME! 🚀
+      "prefer-const": "error", // Use const for variables never reassigned
+      "no-var": "error", // Disallow var, use let/const instead
+
       // Spacing rules (disabled for initial setup - TODO: Fix in separate PR)
       "arrow-spacing": "off",
       "space-before-blocks": "off",
diff --git a/lib/documents.js b/lib/documents.js
index be280c32..ebe1ec2b 100644
--- a/lib/documents.js
+++ b/lib/documents.js
@@ -3,12 +3,12 @@
 */
 'use strict';
 
-var requester  = require('./requester.js');
-var mlutil     = require('./mlutil.js');
-var Operation  = require('./operation.js');
-var qb         = require('./query-builder.js').lib;
-var pathModule = require('path');
-var fs         = require('fs');
+const requester  = require('./requester.js');
+const mlutil     = require('./mlutil.js');
+const Operation  = require('./operation.js');
+const qb         = require('./query-builder.js').lib;
+const pathModule = require('path');
+const fs         = require('fs');
 const stream = require('stream');
 const bldrbase = require('./plan-builder-base.js');
 const duplexify = require('duplexify');
@@ -16,7 +16,7 @@ const duplexify = require('duplexify');
 /** @ignore */
 function addDocumentUri(documents, document) {
   if (document != null) {
-    var uri = document.uri;
+    const uri = document.uri;
     if ((typeof uri === 'string' || uri instanceof String) && uri.length > 0) {
       documents.push(uri);
     }
@@ -35,36 +35,36 @@ function getDocumentUris(documents) {
 function compareDocuments(firstDoc, secondDoc) {
   const hasFirstDoc  = (firstDoc  !== null);
   const hasSecondDoc = (secondDoc !== null);
-  if (!hasFirstDoc && !hasSecondDoc) return  0;
-  if (!hasFirstDoc && hasSecondDoc)  return -1;
-  if (hasFirstDoc  && !hasSecondDoc) return  1;
+  if (!hasFirstDoc && !hasSecondDoc) {return  0;}
+  if (!hasFirstDoc && hasSecondDoc)  {return -1;}
+  if (hasFirstDoc  && !hasSecondDoc) {return  1;}
   const firstUri  = firstDoc.uri;
   const secondUri = secondDoc.uri;
   const hasFirstUri  = ((typeof firstUri  === 'string' || firstUri  instanceof String) && firstUri.length  > 0);
   const hasSecondUri = ((typeof secondUri === 'string' || secondUri instanceof String) && secondUri.length > 0);
-  if (!hasFirstUri && !hasSecondUri) return  0;
-  if (!hasFirstUri && hasSecondUri)  return -1;
-  if (hasFirstUri  && !hasSecondUri) return  1;
-  if (firstUri < secondUri) return -1;
-  if (firstUri > secondUri) return  1;
+  if (!hasFirstUri && !hasSecondUri) {return  0;}
+  if (!hasFirstUri && hasSecondUri)  {return -1;}
+  if (hasFirstUri  && !hasSecondUri) {return  1;}
+  if (firstUri < secondUri) {return -1;}
+  if (firstUri > secondUri) {return  1;}
   return 0;
 }
 
 /** @ignore */
 function uriErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var uri = operation.uri;
+  const uri = operation.uri;
   return (uri == null) ? message :
     (message+' (on '+uri+')');
 }
 /** @ignore */
 function uriListErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var uris = operation.uris;
+  const uris = operation.uris;
   return ((!Array.isArray(uris)) || uris.length === 0) ?
     message : (message+' (on '+uris.join(', ')+')');
 }
@@ -89,15 +89,15 @@ function Documents(client) {
 /** @ignore */
 function probeOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var statusCode = operation.responseStatusCode;
-  var exists     = (statusCode === 200) ? true : false;
+  const statusCode = operation.responseStatusCode;
+  const exists     = (statusCode === 200) ? true : false;
   if (operation.contentOnly === true) {
     return exists;
   }
 
-  var output = exists ? operation.responseHeaders : {};
+  const output = exists ? operation.responseHeaders : {};
   output.uri    = operation.uri;
   output.exists = exists;
 
@@ -106,9 +106,9 @@ function probeOutputTransform(/*headers, data*/) {
 
 function protectOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var output = {
+  const output = {
     uri:                operation.uri,
     temporalCollection: operation.temporalCollection,
     level:              operation.level
@@ -119,9 +119,9 @@ function protectOutputTransform(/*headers, data*/) {
 
 function wipeOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var output = {
+  const output = {
     uri:                operation.uri,
     temporalCollection: operation.temporalCollection,
     wiped:              true
@@ -133,7 +133,7 @@ function wipeOutputTransform(/*headers, data*/) {
 function advanceLsqtOutputTransform(headers) {
   /*jshint validthis:true */
 
-  var output = {
+  const output = {
     lsqt: headers.lsqt
   };
 
@@ -227,11 +227,11 @@ function probeDocumentsImpl(contentOnly, args) {
     throw new Error('must supply uri for document check()');
   }
 
-  var params = (args.length === 1 && typeof args[0] !== 'string' && !(args[0] instanceof String)) ? args[0] : null;
+  const params = (args.length === 1 && typeof args[0] !== 'string' && !(args[0] instanceof String)) ? args[0] : null;
 
-  var uri = null;
-  var txid = null;
-  var path = '/v1/documents?format=json';
+  let uri = null;
+  let txid = null;
+  let path = '/v1/documents?format=json';
   // params as list
   if (params === null) {
     uri = args[0];
@@ -257,7 +257,7 @@ function probeDocumentsImpl(contentOnly, args) {
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'HEAD');
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'probe document', this.client, requestOptions, 'empty', 'empty'
       );
   operation.uri              = uri;
@@ -296,19 +296,19 @@ function probeDocumentsImpl(contentOnly, args) {
  */
 Documents.prototype.protect = function protectDocument() {
   /*jshint validthis:true */
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
-  var uri           = null;
-  var tempColl      = null;
-  var duration      = null;
-  var expireTime    = null;
-  var level         = 'noDelete';
-  var archivePath   = null;
+  let uri           = null;
+  let tempColl      = null;
+  let duration      = null;
+  let expireTime    = null;
+  let level         = 'noDelete';
+  let archivePath   = null;
 
   // Params as single object
   if (argLen === 1) {
-    var obj = args[0];
+    const obj = args[0];
     if (obj.uri === void 0) {
       throw new Error('must specify uri');
     } else {
@@ -346,7 +346,7 @@ Documents.prototype.protect = function protectDocument() {
     } else {
       expireTime = args[2];
     }
-    var levels = ['noWipe', 'noDelete', 'noUpdate'];
+    const levels = ['noWipe', 'noDelete', 'noUpdate'];
     if (levels.indexOf(args[3]) !== -1) {
       level = args[3];
     } else {
@@ -365,7 +365,7 @@ Documents.prototype.protect = function protectDocument() {
     }
   }
 
-  var path = '/v1/documents/protection?uri=' + encodeURIComponent(uri);
+  let path = '/v1/documents/protection?uri=' + encodeURIComponent(uri);
   path += '&temporal-collection=' + encodeURIComponent(tempColl);
   if (duration !== null) {
     path += '&duration=' + encodeURIComponent(duration);
@@ -379,7 +379,7 @@ Documents.prototype.protect = function protectDocument() {
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'POST');
 
-  var operation = new Operation(
+  const operation = new Operation(
       'protect document', this.client, requestOptions, 'empty', 'empty'
       );
   operation.uri                = uri;
@@ -411,15 +411,15 @@ Documents.prototype.protect = function protectDocument() {
  */
 Documents.prototype.wipe = function wipeDocument() {
   /*jshint validthis:true */
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
-  var uri           = null;
-  var tempColl      = null;
+  let uri           = null;
+  let tempColl      = null;
 
   // Params as single object
   if (argLen === 1) {
-    var obj = args[0];
+    const obj = args[0];
     if (obj.uri === void 0) {
       throw new Error('must specify uri');
     } else {
@@ -440,13 +440,13 @@ Documents.prototype.wipe = function wipeDocument() {
     tempColl = args[1];
   }
 
-  var path = '/v1/documents?uri=' + encodeURIComponent(uri);
+  let path = '/v1/documents?uri=' + encodeURIComponent(uri);
   path += '&temporal-collection=' + encodeURIComponent(tempColl);
   path += '&result=wiped';
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'DELETE');
 
-  var operation = new Operation(
+  const operation = new Operation(
       'wipe document', this.client, requestOptions, 'empty', 'empty'
       );
   operation.uri                = uri;
@@ -471,10 +471,10 @@ Documents.prototype.wipe = function wipeDocument() {
  */
 Documents.prototype.advanceLsqt = function temporalAdvanceLsqt() {
   /*jshint validthis:true */
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
-  var tempColl = null;
-  var lag      = null;
+  let tempColl = null;
+  let lag      = null;
 
   // Positional case
   if (typeof args[0] === 'string' || args[0] instanceof String) {
@@ -489,7 +489,7 @@ Documents.prototype.advanceLsqt = function temporalAdvanceLsqt() {
   }
   // Object case
   else {
-    var obj = args[0];
+    const obj = args[0];
     if (obj.temporalCollection === void 0) {
       throw new Error('must specify temporalCollection');
     } else {
@@ -504,7 +504,7 @@ Documents.prototype.advanceLsqt = function temporalAdvanceLsqt() {
     }
   }
 
-  var path = '/v1/temporal/collections/' + encodeURIComponent(tempColl);
+  let path = '/v1/temporal/collections/' + encodeURIComponent(tempColl);
   path += '?result=advance-lsqt';
   if (lag !== null) {
     path += '&lag=' + encodeURIComponent(lag);
@@ -512,7 +512,7 @@ Documents.prototype.advanceLsqt = function temporalAdvanceLsqt() {
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'POST');
 
-  var operation = new Operation(
+  const operation = new Operation(
       'advance LSQT', this.client, requestOptions, 'empty', 'empty'
       );
   // operation.temporalCollection = tempColl;
@@ -531,9 +531,9 @@ function readStatusValidator(statusCode) {
 /** @ignore */
 function singleReadOutputTransform(headers, data) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var hasData = (data != null);
+  const hasData = (data != null);
   if (hasData &&
       (data.errorResponse != null) &&
       data.errorResponse.statusCode === 404
@@ -541,15 +541,15 @@ function singleReadOutputTransform(headers, data) {
     return [];
   }
 
-  var content = hasData ? data : null;
+  const content = hasData ? data : null;
 
   if (operation.contentOnly === true) {
     return [content];
   }
 
-  var categories = operation.categories;
+  const categories = operation.categories;
 
-  var document = (categories.length === 1 && categories[0] === 'content') ?
+  const document = (categories.length === 1 && categories[0] === 'content') ?
       {content: content} : collectMetadata(content);
 
   if(operation.uris){
@@ -557,21 +557,21 @@ function singleReadOutputTransform(headers, data) {
   }
   document.category = categories;
 
-  var format = headers.format;
+  const format = headers.format;
   if (typeof format === 'string' || format instanceof String) {
     document.format = format;
     if (format !== 'json') {
-      var contentLength = headers.contentLength;
+      const contentLength = headers.contentLength;
       if (contentLength != null) {
         document.contentLength = contentLength;
       }
     }
   }
 
-  var headerList  = ['contentType', 'versionId'];
-  var headerKey   = null;
-  var headerValue = null;
-  var i = 0;
+  const headerList  = ['contentType', 'versionId'];
+  let headerKey   = null;
+  let headerValue = null;
+  let i = 0;
   for (i = 0; i < headerList.length; i++) {
     headerKey = headerList[i];
     headerValue = headers[headerKey];
@@ -625,15 +625,15 @@ function readDocumentsImpl(contentOnly, args) {
     throw new Error('must specify at least one document to read');
   }
 
-  var uris = null;
-  var categories = null;
-  var txid = null;
-  var transform = null;
-  var contentType = null;
-  var range = null;
-  var timestamp = null;
+  let uris = null;
+  let categories = null;
+  let txid = null;
+  let transform = null;
+  let contentType = null;
+  let range = null;
+  let timestamp = null;
 
-  var arg = args[0];
+  const arg = args[0];
   if (Array.isArray(arg)) {
     uris = arg;
   } else if (typeof arg === 'string' || arg instanceof String) {
@@ -661,7 +661,7 @@ function readDocumentsImpl(contentOnly, args) {
   }
 
   if (categories != null) {
-    var i = 0;
+    let i = 0;
     for (i = 0; i < categories.length; i++) {
       if(categories[i] === 'rawContent'){
         if(categories.length>1) {
@@ -675,7 +675,7 @@ function readDocumentsImpl(contentOnly, args) {
     }
   }
 
-  var path = '/v1/documents?format=json&uri='+
+  let path = '/v1/documents?format=json&uri='+
     uris.map(encodeURIComponent).join('&uri=');
   path += '&category=' + categories.join('&category=');
   if (txid != null) {
@@ -691,7 +691,7 @@ function readDocumentsImpl(contentOnly, args) {
     }
   }
 
-  var isSinglePayload = (
+  const isSinglePayload = (
       uris.length === 1 && (
           (categories.length === 1 && categories[0] === 'content') ||
           categories.indexOf('content') === -1
@@ -703,7 +703,7 @@ function readDocumentsImpl(contentOnly, args) {
         Accept: 'multipart/mixed; boundary='+mlutil.multipartBoundary
     };
   } else {
-    var hasContentType = false;
+    let hasContentType = false;
     if (contentType != null) {
       if (typeof contentType === 'string' || contentType instanceof String) {
         hasContentType = true;
@@ -716,7 +716,7 @@ function readDocumentsImpl(contentOnly, args) {
       if (!Array.isArray(range)) {
         throw new Error('byte range parameter for reading binary document is not an array: '+range);
       }
-      var bytes = null;
+      let bytes = null;
       switch (range.length) {
       case 0:
         throw new Error('no start length for byte range parameter for reading binary document');
@@ -762,7 +762,7 @@ function readDocumentsImpl(contentOnly, args) {
   }
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read documents', this.client, requestOptions, 'empty',
         (isSinglePayload ? 'single' : 'multipart')
       );
@@ -815,8 +815,8 @@ Documents.prototype.createWriteStream = function createWriteStream(document) {
     throw new Error('must write to stream to supply document content');
   }
 
-  var categories = document.categories;
-  var hasCategories = Array.isArray(categories) && categories.length > 0;
+  let categories = document.categories;
+  const hasCategories = Array.isArray(categories) && categories.length > 0;
   if (!hasCategories && (typeof categories === 'string' || categories instanceof String)) {
     categories = [categories];
   }
@@ -830,16 +830,16 @@ Documents.prototype.createWriteStream = function createWriteStream(document) {
 /** @ignore */
 function writeStreamImpl(document, categories) {
   /*jshint validthis:true */
-  var endpoint = '/v1/documents';
+  let endpoint = '/v1/documents';
 
-  var txid = getTxid(document);
+  const txid = getTxid(document);
 
-  var writeParams = addWriteParams(document, categories, txid);
+  const writeParams = addWriteParams(document, categories, txid);
   if (writeParams.length > 0) {
     endpoint += writeParams;
   }
 
-  var multipartBoundary = mlutil.multipartBoundary;
+  const multipartBoundary = mlutil.multipartBoundary;
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), endpoint, 'POST');
   requestOptions.headers = {
       'Content-Type': 'multipart/mixed; boundary='+multipartBoundary,
@@ -847,14 +847,14 @@ function writeStreamImpl(document, categories) {
   };
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write document stream', this.client, requestOptions, 'chunkedMultipart', 'single'
       );
   operation.isReplayable = false;
   operation.uri = document.uri;
 
   // TODO: treat as chunked single document if no properties
-  var requestPartList = [];
+  const requestPartList = [];
   addDocumentParts(operation, requestPartList, document, true);
   operation.requestDocument = requestPartList;
 
@@ -867,14 +867,14 @@ function writeStreamImpl(document, categories) {
 /** @ignore */
 function singleWriteOutputTransform(headers, data) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var uri = operation.uri;
+  let uri = operation.uri;
 
   if (uri == null) {
-    var location = headers.location;
+    const location = headers.location;
     if (location != null) {
-      var startsWith = '/v1/documents?uri=';
+      const startsWith = '/v1/documents?uri=';
       if (location.length > startsWith.length &&
           location.substr(0, startsWith.length) === startsWith) {
         uri = location.substr(startsWith.length);
@@ -886,21 +886,21 @@ function singleWriteOutputTransform(headers, data) {
     return [uri];
   }
 
-  var document = {uri: uri};
+  const document = {uri: uri};
 
-  var categories = operation.categories;
+  const categories = operation.categories;
   if (categories == null) {
     document.categories = categories;
   }
 
-  var contentType = (data == null) ? null : data['mime-type'];
+  const contentType = (data == null) ? null : data['mime-type'];
   if (contentType == null) {
     document.contentType = contentType;
   }
 
-  var wrapper = {documents: [document]};
+  const wrapper = {documents: [document]};
 
-  var systemTime = headers.systemTime;
+  const systemTime = headers.systemTime;
   if (systemTime != null) {
     wrapper.systemTime = systemTime;
   }
@@ -911,7 +911,7 @@ function singleWriteOutputTransform(headers, data) {
 function writeListOutputTransform(headers, data) {
 //  var operation = this;
 
-  var systemTime = headers.systemTime;
+  const systemTime = headers.systemTime;
   if (systemTime == null) {
     return data;
   }
@@ -968,10 +968,10 @@ function writeDocumentsImpl(contentOnly, args) {
     throw new Error('must provide uris for document write()');
   }
 
-  var arg = args[0];
+  const arg = args[0];
 
-  var documents = arg.documents;
-  var params = (documents == null) ? null : arg;
+  let documents = arg.documents;
+  const params = (documents == null) ? null : arg;
   if (params !== null) {
     if (!Array.isArray(documents)) {
       documents = [documents];
@@ -982,24 +982,24 @@ function writeDocumentsImpl(contentOnly, args) {
     documents = args;
   }
 
-  var isSingleDoc = (documents.length === 1);
+  const isSingleDoc = (documents.length === 1);
 
-  var document      = isSingleDoc ? documents[0] : null;
-  var hasDocument   = (document != null);
-  var hasContent    = hasDocument && (document.content != null);
+  const document      = isSingleDoc ? documents[0] : null;
+  const hasDocument   = (document != null);
+  const hasContent    = hasDocument && (document.content != null);
 
-  var requestParams  =
+  const requestParams  =
     (params !== null) ? params   :
     (hasDocument)     ? document :
     null;
 
-  var categories = (requestParams == null) ? null : requestParams.categories;
+  let categories = (requestParams == null) ? null : requestParams.categories;
   if (typeof categories === 'string' || categories instanceof String) {
     categories = [categories];
   }
 
   if (categories != null) {
-    for (var i = 0; i < categories.length; i++) {
+    for (let i = 0; i < categories.length; i++) {
       categories[i] = categories[i] === 'metadataValues' ? 'metadata-values' : categories[i];
     }
   }
@@ -1017,19 +1017,19 @@ function writeDocumentsImpl(contentOnly, args) {
 /** @ignore */
 function writeMetadata(document, categories) {
   /*jshint validthis:true */
-  var uri = document.uri;
+  const uri = document.uri;
 
-  var endpoint = '/v1/documents?uri='+encodeURIComponent(uri);
+  let endpoint = '/v1/documents?uri='+encodeURIComponent(uri);
 
   if (!Array.isArray(categories)) {
     categories = [];
   }
 
-  var hasCategories = (categories.length > 0);
+  let hasCategories = (categories.length > 0);
   if (!hasCategories) {
-    var categoryCheck = ['collections', 'permissions', 'quality', 'properties', 'metadataValues'];
-    var category = null;
-    var i = 0;
+    const categoryCheck = ['collections', 'permissions', 'quality', 'properties', 'metadataValues'];
+    let category = null;
+    let i = 0;
     for (i = 0; i < categoryCheck.length; i++) {
       category = categoryCheck[i];
       if (document[category] != null) {
@@ -1046,12 +1046,12 @@ function writeMetadata(document, categories) {
     endpoint += '&category='+categories.join('&category=');
   }
 
-  var txid = mlutil.convertTransaction(document.txid);
+  const txid = mlutil.convertTransaction(document.txid);
   if (txid != null) {
     endpoint += '&txid='+mlutil.getTxidParam(txid);
   }
 
-  var requestHeaders = {
+  const requestHeaders = {
       'Accept':       'application/json',
       'Content-Type': 'application/json'
   };
@@ -1060,7 +1060,7 @@ function writeMetadata(document, categories) {
   requestOptions.headers = requestHeaders;
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write single metadata', this.client, requestOptions, 'single', 'empty'
       );
   operation.uri = uri;
@@ -1075,32 +1075,32 @@ function writeMetadata(document, categories) {
 /** @ignore */
 function writeContent(contentOnly, document, requestParams, categories, requestType) {
   /*jshint validthis:true */
-  var content     = document.content;
-  var hasContent  = (content != null);
+  const content     = document.content;
+  const hasContent  = (content != null);
 
-  var endpoint = '/v1/documents';
+  let endpoint = '/v1/documents';
 
-  var sep = '?';
+  let sep = '?';
 
-  var txid = getTxid(requestParams);
+  const txid = getTxid(requestParams);
 
-  var writeParams = addWriteParams(requestParams, categories, txid);
+  const writeParams = addWriteParams(requestParams, categories, txid);
   if (writeParams.length > 0) {
     endpoint += writeParams;
     sep = '&';
   }
 
-  var uri    = document.uri;
-  var hasUri = (uri != null);
+  const uri    = document.uri;
+  const hasUri = (uri != null);
 
   if (hasUri) {
     endpoint += sep+'uri='+encodeURIComponent(uri);
     if (sep === '?') { sep = '&'; }
   }
 
-  var i = 0;
+  let i = 0;
 
-  var collections = document.collections;
+  const collections = document.collections;
   if (collections != null) {
     if (Array.isArray(collections)) {
       for (i=0; i < collections.length; i++) {
@@ -1113,12 +1113,12 @@ function writeContent(contentOnly, document, requestParams, categories, requestT
     }
   }
 
-  var permissions = document.permissions;
+  const permissions = document.permissions;
   if (permissions != null) {
-    var permission   = null;
-    var roleName     = null;
-    var capabilities = null;
-    var j = 0;
+    let permission   = null;
+    let roleName     = null;
+    let capabilities = null;
+    let j = 0;
     if (Array.isArray(permissions)) {
       for (i=0; i < permissions.length; i++) {
         permission   = permissions[i];
@@ -1149,28 +1149,28 @@ function writeContent(contentOnly, document, requestParams, categories, requestT
     }
   }
 
-  var quality = document.quality;
+  const quality = document.quality;
   if (quality != null) {
     endpoint += sep+'quality='+quality;
     if (sep === '?') { sep = '&'; }
   }
 
-  var metadataValues = document.metadataValues;
-  for (var key in metadataValues) {
+  const metadataValues = document.metadataValues;
+  for (const key in metadataValues) {
     endpoint += sep+'value:'+key+'='+encodeURIComponent(metadataValues[key]);
   }
 
-  var temporalDocument = document.temporalDocument;
+  const temporalDocument = document.temporalDocument;
   if (temporalDocument != null) {
     endpoint += sep+'temporal-document='+temporalDocument;
     if (sep === '?') { sep = '&'; }
   }
 
-  var requestHeaders = {
+  const requestHeaders = {
     'Accept': 'application/json'
   };
 
-  var writeConfig = addWriteConfig(document, hasUri, content, requestHeaders, sep);
+  const writeConfig = addWriteConfig(document, hasUri, content, requestHeaders, sep);
   if (writeConfig.length > 0) {
     endpoint += writeConfig;
     if (sep === '?') { sep = '&'; }
@@ -1179,7 +1179,7 @@ function writeContent(contentOnly, document, requestParams, categories, requestT
   const requestOptions     = mlutil.newRequestOptions(this.client.getConnectionParams(), endpoint, hasUri ? 'PUT' : 'POST');
   requestOptions.headers = requestHeaders;
   mlutil.addTxidHeaders(requestOptions, txid);
-  var operation = new Operation(
+  const operation = new Operation(
       'write single document', this.client, requestOptions, requestType, 'empty'
       );
   if (hasUri) {
@@ -1205,18 +1205,18 @@ function writeDocumentList(contentOnly, documents, requestParams, categories) {
     documents = documents.sort(compareDocuments);
   }
 
-  var endpoint = '/v1/documents';
+  let endpoint = '/v1/documents';
 
-  var txid = getTxid(requestParams);
+  const txid = getTxid(requestParams);
 
-  var writeParams = addWriteParams(requestParams, categories, txid);
+  const writeParams = addWriteParams(requestParams, categories, txid);
   if (writeParams.length > 0) {
     endpoint += writeParams;
   }
 
-  var multipartBoundary = mlutil.multipartBoundary;
+  const multipartBoundary = mlutil.multipartBoundary;
 
-  var requestHeaders = {
+  const requestHeaders = {
       'Accept':       'application/json',
       'Content-Type': 'multipart/mixed; boundary='+multipartBoundary
   };
@@ -1225,7 +1225,7 @@ function writeDocumentList(contentOnly, documents, requestParams, categories) {
   requestOptions.headers = requestHeaders;
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write document list', this.client, requestOptions, 'multipart', 'single'
       );
   operation.uris = getDocumentUris(documents);
@@ -1235,8 +1235,8 @@ function writeDocumentList(contentOnly, documents, requestParams, categories) {
 
   operation.multipartBoundary = multipartBoundary;
 
-  var requestPartList = [];
-  for (var i=0; i < documents.length; i++) {
+  const requestPartList = [];
+  for (let i=0; i < documents.length; i++) {
     addDocumentParts(operation, requestPartList, documents[i], false);
   }
   operation.requestPartList = requestPartList;
@@ -1256,9 +1256,9 @@ function getTxid(requestParams) {
 }
 /** @ignore */
 function addWriteParams(requestParams, categories, txidRaw) {
-  var writeParams = '';
-  var txid = mlutil.convertTransaction(txidRaw);
-  var sep = '?';
+  let writeParams = '';
+  const txid = mlutil.convertTransaction(txidRaw);
+  let sep = '?';
   if (requestParams != null) {
     if (Array.isArray(categories) && categories.length > 0) {
       writeParams += sep+'category='+categories.join('&category=');
@@ -1268,21 +1268,21 @@ function addWriteParams(requestParams, categories, txidRaw) {
       writeParams += sep+'txid='+mlutil.getTxidParam(txid);
       if (sep !== '&') { sep = '&'; }
     }
-    var transform = mlutil.endpointTransform(requestParams.transform);
+    const transform = mlutil.endpointTransform(requestParams.transform);
     if (transform != null) {
       writeParams += sep+transform;
       if (sep !== '&') { sep = '&'; }
     }
-    var forestName = requestParams.forestName;
+    const forestName = requestParams.forestName;
     if (forestName != null) {
       writeParams += sep+'forest-name='+encodeURIComponent(forestName);
       if (sep !== '&') { sep = '&'; }
     }
-    var temporalCollection = requestParams.temporalCollection;
+    const temporalCollection = requestParams.temporalCollection;
     if (temporalCollection != null) {
       writeParams += sep+'temporal-collection='+encodeURIComponent(temporalCollection);
       if (sep !== '&') { sep = '&'; }
-      var systemTime = requestParams.systemTime;
+      const systemTime = requestParams.systemTime;
       if (typeof systemTime === 'string' || systemTime instanceof String) {
         writeParams += '&system-time='+encodeURIComponent(systemTime);
       } else if (Object.prototype.toString.call(systemTime) === '[object Date]') {
@@ -1295,16 +1295,16 @@ function addWriteParams(requestParams, categories, txidRaw) {
 }
 /** @ignore */
 function addWriteConfig(document, hasUri, content, headers, sep) {
-  var writeConfig = '';
+  let writeConfig = '';
 
-  var isBody = (sep !== '; ');
+  const isBody = (sep !== '; ');
 
   if (!hasUri) {
-    var extension = document.extension;
+    const extension = document.extension;
     if (extension != null) {
       writeConfig += sep+'extension='+extension;
       if (isBody && sep === '?') { sep = '&'; }
-      var directory = document.directory;
+      const directory = document.directory;
       if (directory != null) {
         writeConfig += sep+'directory='+
             (isBody ? encodeURIComponent(directory) : directory);
@@ -1312,7 +1312,7 @@ function addWriteConfig(document, hasUri, content, headers, sep) {
     }
   }
 
-  var versionId = document.versionId;
+  const versionId = document.versionId;
   if (versionId != null) {
     if (isBody) {
       headers['If-Match'] = versionId;
@@ -1321,10 +1321,10 @@ function addWriteConfig(document, hasUri, content, headers, sep) {
     }
   }
 
-  var contentType    = document.contentType;
-  var hasContentType = (contentType != null);
-  var format         = document.format;
-  var hasFormat      = (format != null);
+  let contentType    = document.contentType;
+  let hasContentType = (contentType != null);
+  let format         = document.format;
+  let hasFormat      = (format != null);
 
   if (hasContentType) {
     if (!hasFormat) {
@@ -1399,10 +1399,10 @@ function addWriteConfig(document, hasUri, content, headers, sep) {
 }
 /** @ignore */
 function addDocumentParts(operation, partList, document, isContentOptional) {
-  var uri    = document.uri;
-  var hasUri = (uri != null);
+  const uri    = document.uri;
+  const hasUri = (uri != null);
 
-  var disposition = '';
+  let disposition = '';
   if (hasUri) {
     disposition = 'attachment; filename="'+uri+'"';
     if (document.temporalDocument != null) {
@@ -1412,7 +1412,7 @@ function addDocumentParts(operation, partList, document, isContentOptional) {
     disposition = 'inline';
   }
 
-  var metadata = collectMetadata(document);
+  const metadata = collectMetadata(document);
   if (metadata != null) {
     partList.push({
       headers:{
@@ -1423,13 +1423,13 @@ function addDocumentParts(operation, partList, document, isContentOptional) {
     });
   }
 
-  var content    = document.content;
-  var hasContent = (content != null);
+  const content    = document.content;
+  const hasContent = (content != null);
   if (hasContent || isContentOptional) {
-    var headers = {};
-    var part    = {headers: headers};
+    const headers = {};
+    const part    = {headers: headers};
 
-    var writeConfig = addWriteConfig(document, hasUri, content, headers, '; ');
+    const writeConfig = addWriteConfig(document, hasUri, content, headers, '; ');
     if (writeConfig.length > 0) {
       disposition += writeConfig;
     }
@@ -1446,11 +1446,11 @@ function addDocumentParts(operation, partList, document, isContentOptional) {
 
 /** @ignore */
 function collectMetadata(document) {
-  var metadata = null;
+  let metadata = null;
   // TODO: create array wrapper for collections, capabilities
-  var metadataCategories = ['collections', 'permissions', 'quality', 'properties', 'metadataValues'];
-  for (var i = 0; i < metadataCategories.length; i++) {
-    var category = metadataCategories[i];
+  const metadataCategories = ['collections', 'permissions', 'quality', 'properties', 'metadataValues'];
+  for (let i = 0; i < metadataCategories.length; i++) {
+    const category = metadataCategories[i];
     if (document !== null) {
       if (document[category] != null) {
         if (metadata === null) {
@@ -1466,18 +1466,18 @@ function collectMetadata(document) {
 /** @ignore */
 function removeOutputTransform(headers/*, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   if (operation.contentOnly === true) {
     return operation.uris;
   }
 
-  var wrapper = {
+  const wrapper = {
     uris:    operation.uris,
     removed: true
   };
 
-  var systemTime = headers.systemTime;
+  const systemTime = headers.systemTime;
   if (systemTime != null) {
     wrapper.systemTime = systemTime;
   }
@@ -1524,13 +1524,13 @@ function removeDocumentImpl(contentOnly, args) {
     throw new Error('must provide uris for document remove()');
   }
 
-  var uris = null;
-  var txid = null;
-  var temporalCollection = null;
-  var systemTime = null;
-  var versionId = null;
+  let uris = null;
+  let txid = null;
+  let temporalCollection = null;
+  let systemTime = null;
+  let versionId = null;
 
-  var arg = args[0];
+  const arg = args[0];
   if (Array.isArray(arg)) {
     uris = arg;
   } else if (typeof arg === 'string' || arg instanceof String) {
@@ -1550,7 +1550,7 @@ function removeDocumentImpl(contentOnly, args) {
     versionId = arg.versionId;
   }
 
-  var path = '/v1/documents?uri='+
+  let path = '/v1/documents?uri='+
     uris.map(encodeURIComponent).join('&uri=');
   if (txid != null) {
     path += '&txid='+mlutil.getTxidParam(txid);
@@ -1572,7 +1572,7 @@ function removeDocumentImpl(contentOnly, args) {
   }
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'remove document', this.client, requestOptions, 'empty', 'empty'
       );
   operation.uris             = uris;
@@ -1586,22 +1586,22 @@ function removeDocumentImpl(contentOnly, args) {
 
 function removeAllOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   if (operation.contentOnly === true) {
     return operation.collection;
   }
 
-  var output = {
+  const output = {
     exists: false
   };
 
-  var collection = operation.collection;
+  const collection = operation.collection;
   if (collection != null) {
     output.collection = collection;
   }
 
-  var directory = operation.directory;
+  const directory = operation.directory;
   if (directory != null) {
     output.directory = directory;
   }
@@ -1637,18 +1637,18 @@ function removeAllDocumentsImpl(contentOnly, params) {
     throw new Error('No parameters specifying directory or collection to delete');
   }
 
-  var deleteAll     = (params.all === true);
+  const deleteAll     = (params.all === true);
 
-  var collection    = params.collection;
-  var hasCollection = (collection != null);
+  const collection    = params.collection;
+  const hasCollection = (collection != null);
 
-  var directory     = params.directory;
-  var hasDirectory  = (directory != null);
+  const directory     = params.directory;
+  const hasDirectory  = (directory != null);
 
-  var txid = mlutil.convertTransaction(params.txid);
+  const txid = mlutil.convertTransaction(params.txid);
 
-  var endpoint = '/v1/search';
-  var sep = '?';
+  let endpoint = '/v1/search';
+  let sep = '?';
 
   if (hasCollection || hasDirectory) {
     if (deleteAll) {
@@ -1680,7 +1680,7 @@ function removeAllDocumentsImpl(contentOnly, params) {
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), endpoint, 'DELETE');
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'remove all documents', this.client, requestOptions, 'empty', 'empty'
       );
   if (hasCollection) {
@@ -1752,47 +1752,47 @@ Documents.prototype.query = function queryDocuments(builtQuery, timestamp, resul
 };
 function queryDocumentsImpl(collectionParam, contentOnly, builtQuery, timestamp, resultEstimateCallback) {
   /*jshint validthis:true */
-  var wrapper = qb.makeSearchBody(builtQuery);
-
-  var categories  = wrapper.categories;
-  var optionsName = wrapper.optionsName;
-  var pageStart   = wrapper.pageStart;
-  var pageLength  = wrapper.pageLength;
-  var txid        = mlutil.convertTransaction(wrapper.txid);
-  var transform   = wrapper.transform;
-  var view        = wrapper.view;
-  var searchBody  = wrapper.searchBody;
-
-  var returnDocuments = (pageLength !== 0);
+  const wrapper = qb.makeSearchBody(builtQuery);
+
+  const categories  = wrapper.categories;
+  const optionsName = wrapper.optionsName;
+  const pageStart   = wrapper.pageStart;
+  const pageLength  = wrapper.pageLength;
+  const txid        = mlutil.convertTransaction(wrapper.txid);
+  const transform   = wrapper.transform;
+  const view        = wrapper.view;
+  const searchBody  = wrapper.searchBody;
+
+  let returnDocuments = (pageLength !== 0);
   if (!returnDocuments && builtQuery.queryType !== 'qbe') {
-    var searchOptions = searchBody.search.options;
+    const searchOptions = searchBody.search.options;
     if (searchOptions !== void 0) {
-      var transformResults = searchOptions['transform-results'];
+      const transformResults = searchOptions['transform-results'];
       if (transformResults !== null && transformResults !== void 0 &&
           transformResults.apply !== 'empty-snippet') {
         throw new Error('cannot snippet with page length of zero');
       }
 
-      var extractResults = searchOptions['extract-document-data'];
+      const extractResults = searchOptions['extract-document-data'];
       if (extractResults !== null && extractResults !== void 0) {
         throw new Error('cannot extract document data with page length of zero');
       }
     }
   }
 
-  var requestPartList = null;
+  let requestPartList = null;
 
-  var isMultipart = false;
+  let isMultipart = false;
 
-  var endpoint = null;
+  let endpoint = null;
   if (builtQuery.queryFormat === void 0) {
     endpoint = '/v1/search?format=json';
   } else if (builtQuery.queryType === 'qbe') {
-    var qbeQuery = searchBody.search.$query;
+    const qbeQuery = searchBody.search.$query;
 
     if (typeof qbeQuery === 'string' || qbeQuery instanceof String) {
-      var options = searchBody.search.options;
-      var part    = {
+      const options = searchBody.search.options;
+      const part    = {
           headers: {'Content-Type': 'application/xml'},
           content: qbeQuery
           };
@@ -1811,7 +1811,7 @@ function queryDocumentsImpl(collectionParam, contentOnly, builtQuery, timestamp,
     endpoint = '/v1/search?format='+builtQuery.queryFormat;
   }
 
-  var multipartBoundary =
+  const multipartBoundary =
     (isMultipart || returnDocuments) ? mlutil.multipartBoundary : null;
 
   if (categories != null) {
@@ -1867,7 +1867,7 @@ function queryDocumentsImpl(collectionParam, contentOnly, builtQuery, timestamp,
   };
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'query documents', this.client, requestOptions,
       (isMultipart     ? 'multipart' : 'single'),
       (returnDocuments ? 'multipart' : 'single')
@@ -1897,7 +1897,7 @@ function queryDocumentsImpl(collectionParam, contentOnly, builtQuery, timestamp,
 /** @ignore */
 function patchOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   return {
     uri: operation.uri
@@ -1940,26 +1940,26 @@ function patchOutputTransform(/*headers, data*/) {
  * a {@link documents#patchResult} success callback.
  */
 Documents.prototype.patch = function patchDocuments() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
 
-  var arg = arguments[0];
+  let arg = arguments[0];
 
-  var params = (argLen === 1) ? arg : null;
+  const params = (argLen === 1) ? arg : null;
 
   // TODO: allow for raw JSON or XML patch
 
-  var uri                = null;
-  var documentOperations = null;
-  var categories         = null;
-  var temporalCollection = null;
-  var temporalDocument   = null;
-  var sourceDocument     = null;
-  var txid               = null;
-  var versionId          = null;
-  var pathlang           = null;
-  var format             = null;
-  var isRawPatch         = false;
-  var i                  = 0;
+  let uri                = null;
+  let documentOperations = null;
+  let categories         = null;
+  let temporalCollection = null;
+  let temporalDocument   = null;
+  let sourceDocument     = null;
+  let txid               = null;
+  let versionId          = null;
+  let pathlang           = null;
+  let format             = null;
+  let isRawPatch         = false;
+  let i                  = 0;
   if (params !== null) {
     uri        = params.uri;
     arg        = params.operations;
@@ -2022,7 +2022,7 @@ Documents.prototype.patch = function patchDocuments() {
     }
   }
 
-  var endpoint = '/v1/documents?uri='+encodeURIComponent(uri);
+  let endpoint = '/v1/documents?uri='+encodeURIComponent(uri);
   if (categories != null) {
     if (!Array.isArray(categories)) {
       categories = [categories];
@@ -2048,7 +2048,7 @@ Documents.prototype.patch = function patchDocuments() {
     endpoint += '&txid=' + mlutil.getTxidParam(txid);
   }
 
-  var patchBody = isRawPatch ? documentOperations : {patch: documentOperations};
+  const patchBody = isRawPatch ? documentOperations : {patch: documentOperations};
   if (!isRawPatch && (pathlang != null)) {
     patchBody.pathlang = pathlang;
   }
@@ -2065,7 +2065,7 @@ Documents.prototype.patch = function patchDocuments() {
   }
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'patch document', this.client, requestOptions, 'single', 'single'
       );
   operation.uri             = uri;
@@ -2099,16 +2099,16 @@ Documents.prototype.patch = function patchDocuments() {
  * strings.
  */
 Documents.prototype.suggest = function suggestDocuments() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
   if (argLen < 1) {
     throw new Error('no partial query text or query with bindings');
   }
 
-  var params   = null;
-  var partial  = null;
-  var query    = null;
-  var bindings = null;
-  var limit    = null;
+  let params   = null;
+  let partial  = null;
+  let query    = null;
+  let bindings = null;
+  let limit    = null;
   switch (argLen) {
   case 1:
     params   = arguments[0];
@@ -2135,10 +2135,10 @@ Documents.prototype.suggest = function suggestDocuments() {
     throw new Error('no query with bindings for document suggestion');
   }
 
-  var wrapper = qb.makeSearchBody(query);
+  const wrapper = qb.makeSearchBody(query);
 
-  var searchBody = wrapper.searchBody;
-  var search = searchBody.search;
+  const searchBody = wrapper.searchBody;
+  const search = searchBody.search;
   if (search == null) {
     throw new Error('cannot get  document suggestions for empty search');
   }
@@ -2146,35 +2146,35 @@ Documents.prototype.suggest = function suggestDocuments() {
     throw new Error('cannot get  document suggestions for Query By Example (QBE)');
   }
 
-  var searchOptions = search.options;
+  let searchOptions = search.options;
   if (searchOptions == null) {
     searchOptions = {};
     search.options = searchOptions;
   }
-  var searchConstraints = searchOptions.constraint;
+  const searchConstraints = searchOptions.constraint;
 
-  var hasBindings = (bindings != null);
+  const hasBindings = (bindings != null);
 
-  var suggestConstraints = hasBindings ? bindings.constraint : null;
-  var sources = copyConstraints(suggestConstraints, searchConstraints);
+  const suggestConstraints = hasBindings ? bindings.constraint : null;
+  const sources = copyConstraints(suggestConstraints, searchConstraints);
   if (sources.length > 0) {
     searchOptions['suggestion-source'] = sources;
   }
 
-  var term = hasBindings ? bindings.term : null;
+  let term = hasBindings ? bindings.term : null;
   if (term == null) {
     term = searchOptions.term;
   }
 
-  var termDefault = null;
+  let termDefault = null;
   if (term != null) {
-    termDefault = term['default'];
+    termDefault = term.default;
     if (termDefault != null) {
       searchOptions['default-suggestion-source'] = termDefault;
     }
   }
 
-  var endpoint = '/v1/suggest?partial-q='+encodeURIComponent(partial);
+  let endpoint = '/v1/suggest?partial-q='+encodeURIComponent(partial);
   if (limit != null) {
     endpoint += '&limit=' + limit;
   }
@@ -2186,7 +2186,7 @@ Documents.prototype.suggest = function suggestDocuments() {
   };
   mlutil.addTxidHeaders(requestOptions, wrapper.txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'search suggest', this.client, requestOptions, 'single', 'single'
       );
   operation.input       = partial;
@@ -2225,19 +2225,19 @@ Documents.prototype.writeAll = function writeAllDocuments(stream,options) {
 };
 function writeAllDocumentsImpl(inputStream,jobOptions) {
 
-  let path = '/v1/internal/forestinfo';
-  let connectionParams = this.client.getConnectionParams();
+  const path = '/v1/internal/forestinfo';
+  const connectionParams = this.client.getConnectionParams();
   const requestOptions = mlutil.newRequestOptions(connectionParams, path, 'GET');
 
   requestOptions.headers = {
     'Accept':       'application/json',
   };
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read forestInfo', this.client, requestOptions, 'empty', 'single'
   );
 
-  let jobState = {
+  const jobState = {
     docInstance : this,
     stream: inputStream,
     requesterCount: 0,
@@ -2477,20 +2477,20 @@ function queryAllDocumentsImpl(query, jobOptions) {
      throw new Error('Query needs to be a cts query.');
    }
 
-  let path = '/v1/internal/forestinfo';
+  const path = '/v1/internal/forestinfo';
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'POST');
-  let wrapper = {ctsast: bldrbase.exportArg(query.whereClause)};
+  const wrapper = {ctsast: bldrbase.exportArg(query.whereClause)};
 
   requestOptions.headers = {
     'Accept':       'application/json',
     'Content-Type': 'application/json'
   };
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read forestInfo', this.client, requestOptions, 'single', 'single'
   );
   operation.requestBody = mlutil.marshal(wrapper, operation);
-  let jobState = {
+  const jobState = {
     docInstance : this,
     jobOptions: (jobOptions)? mlutil.copyProperties(jobOptions):{},
     urisReadSoFar: 0,
@@ -2542,7 +2542,7 @@ function queryAllDocumentsImpl(query, jobOptions) {
 function onQueryUrisRequest(output) {
   const jobState = this;
   const pageLength = (jobState.jobOptions.batchSize * jobState.jobOptions.queryBatchMultiple);
-  let endpoint = '/v1/internal/uris?filtered=false&start=1&pageLength='+pageLength;
+  const endpoint = '/v1/internal/uris?filtered=false&start=1&pageLength='+pageLength;
   jobState.query = output.query;
   jobState.forests = output.forests;
   jobState.requesterCount = output.forests.length;
@@ -2574,8 +2574,8 @@ function spinForestRequests(jobState, initialization){
 }
 
 function onDocUrisCollected(output) {
-  let jobValues= this;
-  let jobState = jobValues.jobState;
+  const jobValues= this;
+  const jobState = jobValues.jobState;
 
   if(output) {
     const uriArr = output.uriArr;
@@ -2586,7 +2586,7 @@ function onDocUrisCollected(output) {
       const writeSize = jobState.jobOptions.batchSize;
       let i=0;
       while(i<uriArr.length){
-        let writeBatchSize = (i+writeSize)<=uriArr.length? (i+writeSize):uriArr.length;
+        const writeBatchSize = (i+writeSize)<=uriArr.length? (i+writeSize):uriArr.length;
         jobState.stream.write(uriArr.slice(i, writeBatchSize));
         i = writeBatchSize;
       }
@@ -2608,8 +2608,8 @@ function collectDocUris(forestName, jobState){
     finishOnQueryAllDocs(jobState);
     return;
   }
-  let connectionParams = jobState.docInstance.client.getConnectionParams();
-  let requestOptions = mlutil.copyProperties(connectionParams);
+  const connectionParams = jobState.docInstance.client.getConnectionParams();
+  const requestOptions = mlutil.copyProperties(connectionParams);
   let forestEndpoint = jobState.endpoint+'&forest-name='+encodeURIComponent(forestName);
   requestOptions.method = 'POST';
   requestOptions.headers = {
@@ -2621,7 +2621,7 @@ function collectDocUris(forestName, jobState){
     forestEndpoint = forestEndpoint+'&after='+encodeURIComponent(jobState.forestDict[forestName].AfterUri);
   }
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read uris', jobState.docInstance.client, requestOptions, 'single', 'single'
   );
 
@@ -2739,18 +2739,18 @@ Documents.prototype.readAll = function readAllDocuments(stream, options) {
 
 function readAllDocumentsImpl(inputStream, jobOptions) {
 
-  let path = '/v1/internal/forestinfo';
+  const path = '/v1/internal/forestinfo';
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'GET');
 
   requestOptions.headers = {
     'Accept':       'application/json',
   };
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read forestInfo', this.client, requestOptions, 'empty', 'single'
   );
 
-  let jobState = {
+  const jobState = {
     docInstance : this,
     requesterCount: 0,
     docsReadSuccessfully:0,
@@ -3118,8 +3118,8 @@ Documents.prototype.queryToReadAll = function queryToReadAllDocuments(query, opt
 };
 
 function queryToReadAllDocumentsImpl(query,jobOptions){
-  let queryAllJobOptions = {};
-  let readAllJobOptions = {};
+  const queryAllJobOptions = {};
+  const readAllJobOptions = {};
 
   if(!jobOptions){
     jobOptions = {};
@@ -3166,8 +3166,8 @@ function queryToReadAllDocumentsImpl(query,jobOptions){
   queryAllJobOptions.queryToOptions = readAllJobOptions;
 
   const docInstance = this;
-  let queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
-  let queryToReadAllResultStream = new stream.PassThrough({objectMode: true});
+  const queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
+  const queryToReadAllResultStream = new stream.PassThrough({objectMode: true});
   let pipelined = false;
 
   queryAllStream.on('error', function(err){
@@ -3200,19 +3200,19 @@ function queryToReadAllDocumentsImpl(query,jobOptions){
 
 /** @ignore */
 function copyConstraints(suggestConstraints, searchConstraints) {
-  var destination = [];
+  const destination = [];
 
-  var bindLen = Array.isArray(suggestConstraints) ? suggestConstraints.length : 0;
+  const bindLen = Array.isArray(suggestConstraints) ? suggestConstraints.length : 0;
 
-  var constraint = null;
+  let constraint = null;
 
-  var i    = 0;
-  var copy = null;
-  var keys = null;
-  var key  = null;
-  var j    = 0;
+  let i    = 0;
+  let copy = null;
+  let keys = null;
+  let key  = null;
+  let j    = 0;
 
-  var overrides = null;
+  let overrides = null;
   if (bindLen > 0) {
     overrides = {};
     for (i=0; i < bindLen; i++) {
@@ -3237,7 +3237,7 @@ function copyConstraints(suggestConstraints, searchConstraints) {
     copy = null;
   }
 
-  var isCopyKey = null;
+  let isCopyKey = null;
   if (Array.isArray(searchConstraints)) {
     isCopyKey = {
       collection:               true,
@@ -3319,18 +3319,18 @@ Documents.prototype.transformAll = function transformAllDocuments(stream, option
 };
 
 function transformAllDocumentsImpl(inputStream, jobOptions){
-  let path = '/v1/internal/forestinfo';
+  const path = '/v1/internal/forestinfo';
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'GET');
 
   requestOptions.headers = {
     'Accept':       'application/json',
   };
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read forestInfo', this.client, requestOptions, 'empty', 'single'
   );
 
-  let jobState = {
+  const jobState = {
     docInstance : this,
     requesterCount: 0,
     docsTransformedSuccessfully:0,
@@ -3416,7 +3416,7 @@ function onTransformAllInit(output) {
       '&transform='+jobState.jobOptions.transform[0];
   if(jobState.jobOptions.transform.length >1){
     const transformParams = jobState.jobOptions.transform[1];
-    for(let paramName of Object.keys(transformParams)){
+    for(const paramName of Object.keys(transformParams)){
       const paramValue = transformParams[paramName];
       endpoint+= '&'+encodeURIComponent('trans:'+paramName)+'='+encodeURIComponent(paramValue);
     }
@@ -3494,7 +3494,7 @@ function onTransformAllDocs(jobState, writerId) {
 
 function transformDocs(jobState, transformBatchArray, writerId){
 
-  let operation = new Operation(
+  const operation = new Operation(
       'transform docs', jobState.docInstance.client, jobState.requestOptions, 'single', 'single'
   );
   operation.validStatusCodes  = [200, 201];
@@ -3639,8 +3639,8 @@ Documents.prototype.queryToTransformAll = function queryToTransformAllDocuments(
 };
 
 function queryToTransformAllDocumentsImpl(query, jobOptions){
-  let queryAllJobOptions = {};
-  let transformAllJobOptions = {};
+  const queryAllJobOptions = {};
+  const transformAllJobOptions = {};
 
   if(!jobOptions){
     jobOptions = {};
@@ -3687,7 +3687,7 @@ function queryToTransformAllDocumentsImpl(query, jobOptions){
   queryAllJobOptions.queryToOptions = transformAllJobOptions;
 
   const docInstance = this;
-  let queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
+  const queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
   let pipelined = false;
 
   queryAllStream.on('data', function(item){
@@ -3731,18 +3731,18 @@ Documents.prototype.removeAllUris = function removeAllUrisDocuments(stream, opti
 };
 
 function removeAllUrisDocumentsImpl(inputStream, jobOptions){
-  let path = '/v1/internal/forestinfo';
+  const path = '/v1/internal/forestinfo';
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'GET');
 
   requestOptions.headers = {
     'Accept':       'application/json',
   };
 
-  let operation = new Operation(
+  const operation = new Operation(
       'read forestInfo', this.client, requestOptions, 'empty', 'single'
   );
 
-  let jobState = {
+  const jobState = {
     docInstance : this,
     requesterCount: 0,
     docsRemovedSuccessfully:0,
@@ -4003,8 +4003,8 @@ Documents.prototype.queryToRemoveAll = function queryToRemoveAllDocuments(query,
 };
 
 function queryToRemoveAllDocumentsImpl(query, jobOptions){
-  let queryAllJobOptions = {};
-  let removeAllJobOptions = {};
+  const queryAllJobOptions = {};
+  const removeAllJobOptions = {};
 
   if(!jobOptions){
     jobOptions = {};
@@ -4046,7 +4046,7 @@ function queryToRemoveAllDocumentsImpl(query, jobOptions){
   queryAllJobOptions.queryToOptions = removeAllJobOptions;
 
   const docInstance = this;
-  let queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
+  const queryAllStream = queryAllDocumentsImpl.call(docInstance, query, queryAllJobOptions);
   let pipelined = false;
 
   queryAllStream.on('data', function(item){
diff --git a/lib/extlibs.js b/lib/extlibs.js
index a3f03385..656fe487 100644
--- a/lib/extlibs.js
+++ b/lib/extlibs.js
@@ -2,16 +2,16 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /** @ignore */
 function pathErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var path = operation.path;
+  const path = operation.path;
   return (path == null) ? message :
     (message+' (on '+path+' extension library)');
 }
@@ -26,7 +26,7 @@ function pathErrorTransform(message) {
 /** @ignore */
 function emptyOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   return {
     path: operation.path
@@ -54,7 +54,7 @@ ExtLibs.prototype.read = function readExtensionLibrary(path) {
     throw new Error('must specify path when reading the extension library resource');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.path = encodeURI(
       (path.substr(0,5) === '/ext/') ? ('/v1'+path)     :
@@ -62,7 +62,7 @@ ExtLibs.prototype.read = function readExtensionLibrary(path) {
       ('/v1/ext/'+path)
       );
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read extension library', this.client, requestOptions, 'empty', 'single'
       );
   operation.path           = path;
@@ -82,20 +82,20 @@ ExtLibs.prototype.read = function readExtensionLibrary(path) {
  * @param {object|string} source - the library resource
  */
 ExtLibs.prototype.write = function writeExtensionLibrary() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen === 0) {
     throw new Error('no arguments for writing an extension library');
   }
 
-  var path = null;
-  var permissions = null;
-  var contentType = null;
-  var source = null;
-  var i = 0;
-  var arg = null;
+  let path = null;
+  let permissions = null;
+  let contentType = null;
+  let source = null;
+  let i = 0;
+  let arg = null;
 
-  var params = null;
+  let params = null;
   if (argLen === 1) {
     params = args[0];
     path        = params.path;
@@ -103,7 +103,7 @@ ExtLibs.prototype.write = function writeExtensionLibrary() {
     contentType = params.contentType;
     source      = params.source;
   } else {
-    var argMax = Math.min(argLen,4);
+    const argMax = Math.min(argLen,4);
     for (;i < argMax; i++) {
       arg = args[i];
       if (typeof arg === 'string' || arg instanceof String) {
@@ -127,15 +127,15 @@ ExtLibs.prototype.write = function writeExtensionLibrary() {
     throw new Error('must specify the path, content type, and source when writing a extension library');
   }
 
-  var endpoint =
+  let endpoint =
       (path.substr(0,5) === '/ext/') ? ('/v1'+path)     :
       (path.substr(0,1) === '/')     ? ('/v1/ext'+path) :
       ('/v1/ext/'+path);
 
   if (Array.isArray(permissions)) {
-    var role = null;
-    var capabilities = null;
-    var j=null;
+    let role = null;
+    let capabilities = null;
+    let j=null;
     for (i=0; i < permissions.length; i++) {
       arg = permissions[i];
       role = arg['role-name'];
@@ -149,14 +149,14 @@ ExtLibs.prototype.write = function writeExtensionLibrary() {
     }
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method  = 'PUT';
   requestOptions.headers = {
       'Content-Type': contentType
   };
   requestOptions.path = encodeURI(endpoint);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write extension library', this.client, requestOptions, 'single', 'empty'
       );
   operation.path            = path;
@@ -178,7 +178,7 @@ ExtLibs.prototype.remove = function removeExtensionLibrary(path) {
     throw new Error('must specify path when deleting the extension library resource');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'DELETE';
   requestOptions.path = encodeURI(
     (path.substr(0,5) === '/ext/') ? ('/v1'+path)     :
@@ -186,7 +186,7 @@ ExtLibs.prototype.remove = function removeExtensionLibrary(path) {
     ('/v1/ext/'+path)
     );
 
-  var operation = new Operation(
+  const operation = new Operation(
       'remove extension library', this.client, requestOptions, 'empty', 'empty'
       );
   operation.path            = path;
@@ -207,7 +207,7 @@ ExtLibs.prototype.remove = function removeExtensionLibrary(path) {
  * in the directory
  */
 ExtLibs.prototype.list = function listExtensionLibraries(directory) {
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.headers = {
       'Accept': 'application/json'
@@ -222,8 +222,8 @@ ExtLibs.prototype.list = function listExtensionLibraries(directory) {
       requestOptions.path = encodeURI(directory+'/');
     }
   } else {
-    var hasInitialSlash  = (directory.substr(0,1)  === '/');
-    var hasTrailingSlash = (directory.substr(-1,1) === '/');
+    const hasInitialSlash  = (directory.substr(0,1)  === '/');
+    const hasTrailingSlash = (directory.substr(-1,1) === '/');
     if (hasInitialSlash && hasTrailingSlash) {
       requestOptions.path = encodeURI('/v1/ext'  + directory);
     } else if (hasTrailingSlash) {
@@ -235,7 +235,7 @@ ExtLibs.prototype.list = function listExtensionLibraries(directory) {
     }
   }
 
-  var operation = new Operation(
+  const operation = new Operation(
       'list extension libraries', this.client, requestOptions, 'empty', 'single'
       );
 
diff --git a/lib/graphs.js b/lib/graphs.js
index 2c5489d3..b64660e3 100644
--- a/lib/graphs.js
+++ b/lib/graphs.js
@@ -3,15 +3,15 @@
 */
 'use strict';
 
-var requester = require('./requester.js');
+const requester = require('./requester.js');
 var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
-var qb        = require('./query-builder.js');
+const Operation = require('./operation.js');
+const qb        = require('./query-builder.js');
 var mlutil    = require('./mlutil.js');
 
 function uriErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   switch(operation.graphType) {
   case 'default': return message+' (on default graph)';
@@ -19,7 +19,7 @@ function uriErrorTransform(message) {
   case 'managed': return message+' (on managed graphs)';
   }
 
-  var uri = operation.uri;
+  const uri = operation.uri;
   if (typeof uri === 'string' || uri instanceof String) {
     return message+' (on graph '+uri+')';
   }
@@ -28,12 +28,12 @@ function uriErrorTransform(message) {
 }
 function checkOutputTransform(headers, data) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var statusCode = operation.responseStatusCode;
-  var exists     = (statusCode === 200) ? true : false;
+  const statusCode = operation.responseStatusCode;
+  const exists     = (statusCode === 200) ? true : false;
 
-  var output = exists ? operation.responseHeaders : {};
+  const output = exists ? operation.responseHeaders : {};
   output.exists = exists;
 
   return identifyOutput.call(operation, data, output);
@@ -44,9 +44,9 @@ function emptyOutputTransform(headers, data) {
 }
 function identifyOutput(data, output) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var graphType = operation.graphType;
+  const graphType = operation.graphType;
   switch(graphType) {
   case 'named':
     output.defaultGraph = false;
@@ -71,7 +71,7 @@ function identifyOutput(data, output) {
 }
 function listOutputTransform(headers, data) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   if (data == null) {
     return data;
@@ -123,19 +123,19 @@ function Graphs(client) {
  * that receives the triples for the graph in the requested format
  */
 Graphs.prototype.read = function readGraph() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen === 0) {
     throw new Error('must specify the content type when reading a graph');
   }
 
-  var contentType = null;
-  var uri         = null;
-  var category    = null;
-  var txid        = null;
-  var timestamp   = null;
+  let contentType = null;
+  let uri         = null;
+  let category    = null;
+  let txid        = null;
+  let timestamp   = null;
 
-  var testArg = args[0];
+  const testArg = args[0];
   if (typeof testArg === 'string' || testArg instanceof String) {
     if (argLen > 1) {
       uri = testArg;
@@ -144,7 +144,7 @@ Graphs.prototype.read = function readGraph() {
       contentType = testArg;
     }
   } else {
-    var params = testArg;
+    const params = testArg;
     contentType = params.contentType;
     uri         = params.uri;
     category    = params.category;
@@ -155,7 +155,7 @@ Graphs.prototype.read = function readGraph() {
     }
   }
 
-  var endpoint = (uri == null) ?
+  let endpoint = (uri == null) ?
       '/v1/graphs?default' : ('/v1/graphs?graph='+encodeURIComponent(uri));
   if (category !== null && category !== void 0) {
     if (typeof category === 'string' || category instanceof String) {
@@ -178,7 +178,7 @@ Graphs.prototype.read = function readGraph() {
       'Accept': contentType
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read graph', this.client, requestOptions, 'empty', 'single'
       );
   if (uri === null) {
@@ -270,7 +270,7 @@ Graphs.prototype.createMergeStream = function createGraphMergeStream() {
 /** @ignore */
 function changeGraph(action, isStreaming, args) {
   /*jshint validthis:true */
-  var argLen = args.length;
+  const argLen = args.length;
   if (argLen === 0) {
     throw new Error(
         isStreaming ?
@@ -279,16 +279,16 @@ function changeGraph(action, isStreaming, args) {
         );
   }
 
-  var uri         = null;
-  var contentType = null;
-  var repair      = false;
-  var permissions = null;
-  var data        = null;
-  var txid        = null;
+  let uri         = null;
+  let contentType = null;
+  let repair      = false;
+  let permissions = null;
+  let data        = null;
+  let txid        = null;
 
   if (argLen > 1 || (typeof args[0] === 'string' || args[0] instanceof String)) {
-    var arg = null;
-    var i = argLen - 1;
+    let arg = null;
+    let i = argLen - 1;
     for (; i >= 0; i--) {
       arg = args[i];
       if (typeof arg === 'boolean') {
@@ -312,14 +312,14 @@ function changeGraph(action, isStreaming, args) {
       throw new Error('unknown positional parameter for graphs write: '+arg);
     }
   } else {
-    var params = args[0];
+    const params = args[0];
     contentType = params.contentType;
     uri         = params.uri;
     repair      = params.repair || false;
     permissions = params.permissions;
     data        = params.data;
     txid        = mlutil.convertTransaction(params.txid);
-    var noContentType = (contentType == null);
+    const noContentType = (contentType == null);
     if (isStreaming) {
       if (noContentType) {
         throw new Error('named parameters must specify the content type for '+action);
@@ -331,7 +331,7 @@ function changeGraph(action, isStreaming, args) {
     }
   }
 
-  var graphType = null;
+  let graphType = null;
   if (uri === null || uri === void 0) {
     graphType = 'default';
   } else if (uri instanceof InlineGraphUrisDef) {
@@ -340,9 +340,9 @@ function changeGraph(action, isStreaming, args) {
     graphType = 'named';
   }
 
-  var sep = '?';
+  let sep = '?';
 
-  var endpoint = null;
+  let endpoint = null;
   switch(graphType) {
   case 'named':   endpoint = '/v1/graphs?graph='+encodeURIComponent(uri); sep = '&'; break;
   case 'default': endpoint = '/v1/graphs?default';                        sep = '&'; break;
@@ -359,7 +359,7 @@ function changeGraph(action, isStreaming, args) {
     if (sep === '?') { sep = '&'; }
   }
 
-  var permissionsParams = makePermissionsParams(permissions, sep);
+  const permissionsParams = makePermissionsParams(permissions, sep);
   if (permissionsParams !== null) {
     endpoint += permissionsParams;
     if (sep === '?') { sep = '&'; }
@@ -370,7 +370,7 @@ function changeGraph(action, isStreaming, args) {
       'Content-Type': contentType
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       action+' graph', this.client, requestOptions, (isStreaming ? 'chunked' : 'single'), 'empty'
       );
   operation.graphType = graphType;
@@ -400,7 +400,7 @@ function changeGraph(action, isStreaming, args) {
  * called when the triples are removed
  */
 Graphs.prototype.remove = function removeGraph() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   return applyGraph.call(this, 'remove', args);
 };
@@ -416,15 +416,15 @@ Graphs.prototype.remove = function removeGraph() {
  * that receives an object with an exists boolean for the graph
  */
 Graphs.prototype.probe = function probeGraph() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   return applyGraph.call(this, 'probe', args);
 };
 /** @ignore */
 function applyGraph(action, args) {
   /*jshint validthis:true */
-  var uri  = null;
-  var txid = null;
+  let uri  = null;
+  let txid = null;
   switch(args.length) {
   case 0:
     break;
@@ -444,9 +444,9 @@ function applyGraph(action, args) {
     break;
   }
 
-  var endpoint  = null;
-  var graphType = null;
-  var sep       = null;
+  let endpoint  = null;
+  let graphType = null;
+  let sep       = null;
   if (uri === null || uri === void 0) {
     endpoint  = '/v1/graphs?default';
     graphType = 'default';
@@ -471,7 +471,7 @@ function applyGraph(action, args) {
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), endpoint, ((action === 'remove') ? 'DELETE' : 'HEAD'));
 
-  var operation = new Operation(
+  const operation = new Operation(
       action+' graph', this.client, requestOptions, 'empty', 'empty'
       );
   operation.graphType = graphType;
@@ -504,14 +504,14 @@ function applyGraph(action, args) {
  * on the server
  */
 Graphs.prototype.list = function listGraphs() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
 
-  var contentType = null;
-  var txid        = null;
-  var timestamp   = null;
+  let contentType = null;
+  let txid        = null;
+  let timestamp   = null;
   if (argLen > 0) {
-    var arg = null;
-    var i = argLen - 1;
+    let arg = null;
+    let i = argLen - 1;
     for (; i >= 0; i--) {
       arg = arguments[i];
       if (typeof arg === 'string' || arg instanceof String) {
@@ -536,10 +536,10 @@ Graphs.prototype.list = function listGraphs() {
     }
   }
 
-  var noContentType = (contentType === null || contentType === void 0);
+  const noContentType = (contentType === null || contentType === void 0);
 
-  var endpoint = '/v1/graphs';
-  var sep      = '?';
+  let endpoint = '/v1/graphs';
+  let sep      = '?';
 
   if (txid !== null && txid !== void 0) {
     endpoint += sep+'txid='+mlutil.getTxidParam(txid);
@@ -560,7 +560,7 @@ Graphs.prototype.list = function listGraphs() {
     };
   }
 
-  var operation = new Operation(
+  const operation = new Operation(
       'list graphs', this.client, requestOptions, 'empty', 'single'
       );
   if (!noContentType) {
@@ -611,34 +611,34 @@ Graphs.prototype.list = function listGraphs() {
  * that receives the query response
  */
 Graphs.prototype.sparql = function queryGraphSPARQL() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
   if (argLen === 0) {
     throw new Error('must specify content type and query for SPARQL query on graphs');
   }
 
-  var defaultGraphs = null;
-  var namedGraphs   = null;
-  var acceptType    = null;
-  var query         = null;
+  let defaultGraphs = null;
+  let namedGraphs   = null;
+  let acceptType    = null;
+  let query         = null;
 
-  var docQuery        = null;
-  var begin           = null;
-  var end             = null;
-  var base            = null;
-  var txid            = null;
-  var rulesets        = null;
-  var defaultRulesets = null;
-  var optimizeLevel   = null;
-  var bindings        = null;
-  var timestamp       = null;
+  let docQuery        = null;
+  let begin           = null;
+  let end             = null;
+  let base            = null;
+  let txid            = null;
+  let rulesets        = null;
+  let defaultRulesets = null;
+  let optimizeLevel   = null;
+  let bindings        = null;
+  let timestamp       = null;
 
   // TODO: collection, directory?
 
   // Single configuration object
   if (argLen === 1) {
-    var params = args[0];
+    const params = args[0];
     acceptType    = params.contentType;
     defaultGraphs = params.defaultGraphs;
     namedGraphs   = params.namedGraphs;
@@ -667,10 +667,10 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
     query = args[argLen - 1];
   }
 
-  var endpoint = '/v1/graphs/sparql';
-  var sep = '?';
+  let endpoint = '/v1/graphs/sparql';
+  let sep = '?';
 
-  var hasDefaultGraphs = (defaultGraphs !== null && defaultGraphs !== void 0);
+  let hasDefaultGraphs = (defaultGraphs !== null && defaultGraphs !== void 0);
   if (hasDefaultGraphs) {
     defaultGraphs = mlutil.asArray(defaultGraphs);
     if (defaultGraphs.length > 0) {
@@ -681,7 +681,7 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
     }
   }
 
-  var hasNamedGraphs = (namedGraphs !== null && namedGraphs !== void 0);
+  let hasNamedGraphs = (namedGraphs !== null && namedGraphs !== void 0);
   if (hasNamedGraphs) {
     namedGraphs = mlutil.asArray(namedGraphs);
     if (namedGraphs.length > 0) {
@@ -692,7 +692,7 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
     }
   }
 
-  var hasBegin = (begin !== null && begin !== void 0);
+  const hasBegin = (begin !== null && begin !== void 0);
   if (hasBegin) {
     if (begin >= 0) {
       endpoint += sep+'start='+(begin + 1);
@@ -717,7 +717,7 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
     }
   }
 
-  var commonParams = makeCommonSPARQLParams(
+  const commonParams = makeCommonSPARQLParams(
       base, txid, rulesets, defaultRulesets, optimizeLevel, bindings, sep
   );
   if (commonParams !== null) {
@@ -725,14 +725,14 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
     if (sep === '?') { sep = '&'; }
   }
 
-  var contentType = null;
-  var queryBody   = null;
+  let contentType = null;
+  let queryBody   = null;
   if (docQuery === null || docQuery === void 0) {
     contentType = 'application/sparql-query';
     queryBody   = query;
   } else {
     contentType = 'application/json';
-    var builtQuery =
+    const builtQuery =
       (docQuery instanceof qb.lib.QueryBuilder || docQuery.search !== void 0) ? docQuery :
       qb.builder.where(docQuery);
     if (builtQuery.queryType === 'qbe') {
@@ -750,7 +750,7 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
       'Accept':       acceptType
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'SPARQL graph query', this.client, requestOptions, 'single', 'single'
       );
   if (hasDefaultGraphs) {
@@ -795,25 +795,25 @@ Graphs.prototype.sparql = function queryGraphSPARQL() {
  * called when the triples are updated
  */
 Graphs.prototype.sparqlUpdate = function updateGraphSPARQL() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
   if (argLen === 0) {
     throw new Error('must specify data for SPARQL update on graphs');
   }
 
-  var permissions        = null;
-  var usingDefaultGraphs = null;
-  var usingNamedGraphs   = null;
-  var base               = null;
-  var txid               = null;
-  var rulesets           = null;
-  var defaultRulesets    = null;
-  var optimizeLevel      = null;
-  var bindings           = null;
+  let permissions        = null;
+  let usingDefaultGraphs = null;
+  let usingNamedGraphs   = null;
+  let base               = null;
+  let txid               = null;
+  let rulesets           = null;
+  let defaultRulesets    = null;
+  let optimizeLevel      = null;
+  let bindings           = null;
 
-  var arg  = args[0];
-  var data = (argLen === 1) ? arg.data : null;
+  const arg  = args[0];
+  let data = (argLen === 1) ? arg.data : null;
   if (data !== null && data !== void 0) {
     permissions        = arg.permissions;
     usingDefaultGraphs = arg.usingDefaultGraphs;
@@ -831,10 +831,10 @@ Graphs.prototype.sparqlUpdate = function updateGraphSPARQL() {
     data = args[0];
   }
 
-  var endpoint = '/v1/graphs/sparql';
-  var sep = '?';
+  let endpoint = '/v1/graphs/sparql';
+  let sep = '?';
 
-  var hasUsingDefaultGraphs = (usingDefaultGraphs !== null && usingDefaultGraphs !== void 0);
+  let hasUsingDefaultGraphs = (usingDefaultGraphs !== null && usingDefaultGraphs !== void 0);
   if (hasUsingDefaultGraphs) {
     usingDefaultGraphs = mlutil.asArray(usingDefaultGraphs);
     if (usingDefaultGraphs.length > 0) {
@@ -845,7 +845,7 @@ Graphs.prototype.sparqlUpdate = function updateGraphSPARQL() {
     }
   }
 
-  var hasUsingNamedGraphs = (usingNamedGraphs !== null && usingNamedGraphs !== void 0);
+  let hasUsingNamedGraphs = (usingNamedGraphs !== null && usingNamedGraphs !== void 0);
   if (hasUsingNamedGraphs) {
     usingNamedGraphs = mlutil.asArray(usingNamedGraphs);
     if (usingNamedGraphs.length > 0) {
@@ -856,13 +856,13 @@ Graphs.prototype.sparqlUpdate = function updateGraphSPARQL() {
     }
   }
 
-  var permissionsParams = makePermissionsParams(permissions, sep);
+  const permissionsParams = makePermissionsParams(permissions, sep);
   if (permissionsParams !== null) {
     endpoint += permissionsParams;
     if (sep === '?') { sep = '&'; }
   }
 
-  var commonParams = makeCommonSPARQLParams(
+  const commonParams = makeCommonSPARQLParams(
       base, txid, rulesets, defaultRulesets, optimizeLevel, bindings, sep
   );
   if (commonParams !== null) {
@@ -875,7 +875,7 @@ Graphs.prototype.sparqlUpdate = function updateGraphSPARQL() {
       'Content-Type': 'application/sparql-update'
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'SPARQL graph update', this.client, requestOptions, 'single', 'empty'
       );
 
@@ -895,15 +895,15 @@ function makePermissionsParams(permissions, sep) {
     return null;
   }
 
-  var endpoint = '';
+  let endpoint = '';
 
-  var permLen      = permissions.length;
-  var permdef      = null;
-  var roleName     = null;
-  var capabilities = null;
-  var capLen       = 0;
-  var j            = 0;
-  for (var i = 0; i < permLen; i++) {
+  const permLen      = permissions.length;
+  let permdef      = null;
+  let roleName     = null;
+  let capabilities = null;
+  let capLen       = 0;
+  let j            = 0;
+  for (let i = 0; i < permLen; i++) {
     permdef      = permissions[i];
     roleName     = permdef['role-name'];
     capabilities = permdef.capabilities;
@@ -919,8 +919,8 @@ function makePermissionsParams(permissions, sep) {
 function makeCommonSPARQLParams(
     base, txidRaw, rulesets, defaultRulesets, optimizeLevel, bindings, sep
     ) {
-  var endpoint = '';
-  var txid = mlutil.convertTransaction(txidRaw);
+  let endpoint = '';
+  const txid = mlutil.convertTransaction(txidRaw);
   if (base !== null && base !== void 0) {
     endpoint += sep+'base='+encodeURIComponent(base);
     if (sep === '?') { sep = '&'; }
@@ -949,9 +949,9 @@ function makeCommonSPARQLParams(
 }
 function encodeParamValues(name, values) {
   if (Array.isArray(values)) {
-    var result = null;
-    var max = values.length;
-	for (var i=0; i < max; i++) {
+    let result = null;
+    const max = values.length;
+	for (let i=0; i < max; i++) {
 	  if (i === 0) {
         result = encodeURIComponent(name)+'='+encodeURIComponent(values[i]);
 	  } else {
diff --git a/lib/internal.js b/lib/internal.js
index fbe8edb6..bcfbeeff 100644
--- a/lib/internal.js
+++ b/lib/internal.js
@@ -14,7 +14,7 @@ class InternalClass {
         if(!path){
             throw new Error('Path is needed to send request.');
         }
-        let requestOptions = mlutil.newRequestOptions(this.clientObject.getConnectionParams(), path);
+        const requestOptions = mlutil.newRequestOptions(this.clientObject.getConnectionParams(), path);
         if (requestOptionsCallback) {
             requestOptionsCallback(requestOptions);
         }
diff --git a/lib/marklogic.js b/lib/marklogic.js
index 83ad0639..be579a34 100644
--- a/lib/marklogic.js
+++ b/lib/marklogic.js
@@ -2,32 +2,32 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var http                 = require('http');
-var https                = require('https');
-
-var mlutil               = require('./mlutil.js');
-var mllog                = require('./mllog.js');
-
-var documents            = require('./documents.js');
-var Graphs               = require('./graphs.js');
-var Rows                 = require('./rows.js');
-var Values               = require('./values.js');
-var ExtLibs              = require('./extlibs.js');
-var RESTServerProperties = require('./rest-server-properties.js');
-var Transactions         = require('./transactions.js');
-var Transforms           = require('./transforms.js');
-var ResourcesConfig      = require('./resources-config.js');
-var ResourcesExec        = require('./resources-exec.js');
-var serverExec           = require('./server-exec.js');
-
-var queryBuilder         = require('./query-builder.js');
-var patchBuilder         = require('./patch-builder.js');
-var valuesBuilder        = require('./values-builder.js');
-var planBuilder          = require('./plan-builder.js');
-var ctsQueryBuilder      = require('./ctsquery-builder');
-var Operation            = require('./operation.js');
-var requester            = require('./requester.js');
-let internal             = require('./internal.js');
+const http                 = require('http');
+const https                = require('https');
+
+const mlutil               = require('./mlutil.js');
+const mllog                = require('./mllog.js');
+
+const documents            = require('./documents.js');
+const Graphs               = require('./graphs.js');
+const Rows                 = require('./rows.js');
+const Values               = require('./values.js');
+const ExtLibs              = require('./extlibs.js');
+const RESTServerProperties = require('./rest-server-properties.js');
+const Transactions         = require('./transactions.js');
+const Transforms           = require('./transforms.js');
+const ResourcesConfig      = require('./resources-config.js');
+const ResourcesExec        = require('./resources-exec.js');
+const serverExec           = require('./server-exec.js');
+
+const queryBuilder         = require('./query-builder.js');
+const patchBuilder         = require('./patch-builder.js');
+const valuesBuilder        = require('./values-builder.js');
+const planBuilder          = require('./plan-builder.js');
+const ctsQueryBuilder      = require('./ctsquery-builder');
+const Operation            = require('./operation.js');
+const requester            = require('./requester.js');
+const internal             = require('./internal.js');
 
 const proxy              = require('./endpoint-proxy.js');
 const dns = require('dns');
@@ -181,9 +181,9 @@ ExtlibsWrapper.prototype.remove = function removeExtlibsWrapper() {
       );
 };
 ExtlibsWrapper.prototype.write = function writeExtlibsWrapper() {
-  var args = expandExtlibsWrapper.call(this, 'writing', mlutil.asArray.apply(null, arguments));
-  var module = args[0];
-  var ext = mlutil.extension(module);
+  const args = expandExtlibsWrapper.call(this, 'writing', mlutil.asArray.apply(null, arguments));
+  const module = args[0];
+  const ext = mlutil.extension(module);
   if (ext === null) {
     throw new Error(module+' module for '+this.name+' library must have an extension of .mjs, .sjs, or .xqy');
   }
@@ -205,7 +205,7 @@ ExtlibsWrapper.prototype.write = function writeExtlibsWrapper() {
 };
 function expandExtlibsWrapper(action, args) {
   /*jshint validthis:true */
-  var module = (args.length > 0) ? args[0] : null;
+  const module = (args.length > 0) ? args[0] : null;
   if (typeof module !== 'string' && !(module instanceof String)) {
     throw new Error('no module name for '+action+' '+this.name+' library');
   }
@@ -321,7 +321,7 @@ function MarkLogicClient(connectionParams) {
    */
   this.values    = new Values(this);
 
-  var configExtlibs = new ExtLibs(this);
+  const configExtlibs = new ExtLibs(this);
 
   /**
    * Provides access to namespaces that configure the REST server for the client.
@@ -381,7 +381,7 @@ MarkLogicClient.prototype.getConnectionParams = function getConnectionParams() {
  */
 MarkLogicClient.prototype.checkConnection = function checkConnection() {
   const requestOptions = mlutil.newRequestOptions(this.connectionParams, '/v1/ping', 'HEAD');
-  var operation = new Operation(
+  const operation = new Operation(
       'test operation', this, requestOptions, 'empty', 'empty'
       );
   operation.statusCodeValidator = function testStatusCodes(statusCode, response){
@@ -391,7 +391,7 @@ MarkLogicClient.prototype.checkConnection = function checkConnection() {
     return null;
    };
   operation.outputTransform = function addOutputTransform() {
-    var content = null;
+    let content = null;
     if(this.responseStatusCode <300) {
        content = {connected: true};
     } else {
@@ -426,24 +426,24 @@ MarkLogicClient.prototype.invoke                = serverExec.serverInvoke;
  * a success callback receiving an array of uri strings for the created documents.
  */
 MarkLogicClient.prototype.createCollection = function createCollection() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
   if (argLen < 2) {
     throw new Error('must specify both a collection and content objects for document create');
   }
 
-  var collection = arguments[0];
+  const collection = arguments[0];
   if (typeof collection !== 'string' && !(collection instanceof String)) {
     throw new Error('must specify at least one collection for document create');
   }
 
-  var contentArray = arguments[1];
-  var i = 0;
+  let contentArray = arguments[1];
+  let i = 0;
   if (!Array.isArray(contentArray)) {
     i = 1;
     contentArray = arguments;
   }
 
-  var documentList = [];
+  const documentList = [];
   for (; i < contentArray.length; i++) {
     documentList.push({
       collections: collection,
@@ -567,25 +567,25 @@ MarkLogicClient.prototype.removeCollection = function removeCollectionClient(col
  * a success callback receiving an array of uri strings for the written documents.
  */
 MarkLogicClient.prototype.writeCollection = function writeClient() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
   if (argLen < 2) {
     throw new Error('must specify both a collection and mapping object for quick document write');
   }
 
-  var collection = arguments[0];
+  const collection = arguments[0];
   if (typeof collection !== 'string' && !(collection instanceof String)) {
     throw new Error('must specify at least one collection for quick document write');
   }
 
-  var map  = arguments[1];
-  var uris = Object.keys(map);
+  const map  = arguments[1];
+  const uris = Object.keys(map);
   if (uris.length === 0) {
     throw new Error('must map at least one document uri to content for quick document write');
   }
 
-  var documentList = [];
-  var uri = null;
-  var i = 0;
+  const documentList = [];
+  let uri = null;
+  let i = 0;
   for (; i < uris.length; i++) {
     uri = uris[i];
     documentList.push({
@@ -616,14 +616,14 @@ MarkLogicClient.prototype.release = function releaseMarkLogicClient() {
  * must be provided as true for Bunyan (but not for Winston); defaults to false
  */
 MarkLogicClient.prototype.setLogger = function setClientLogger() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
   if (argLen < 1) {
     throw new Error('must provide a logger as the first argument');
   }
 
-  var arg = arguments[0];
+  const arg = arguments[0];
   if (typeof arg === 'string' || arg instanceof String) {
-    var logger = (argLen === 1) ? this.getLogger() : null;
+    const logger = (argLen === 1) ? this.getLogger() : null;
     if (logger instanceof mllog.ConsoleLogger) {
       logger.setLevel(arg);
     } else {
@@ -639,7 +639,7 @@ MarkLogicClient.prototype.setLogger = function setClientLogger() {
 
 /** @ignore */
 MarkLogicClient.prototype.getLogger = function getClientLogger() {
-  var logger = this.logger;
+  let logger = this.logger;
 
   if (logger == null) {
     logger = new mllog.ConsoleLogger();
@@ -663,7 +663,7 @@ MarkLogicClient.prototype.getLogger = function getClientLogger() {
  * @returns {Timestamp} - a Timestamp object.
  */
 MarkLogicClient.prototype.createTimestamp = function databaseCreateTimestamp(value) {
-  let ts = new mlutil.Timestamp(value ? value : null);
+  const ts = new mlutil.Timestamp(value ? value : null);
   return ts;
 };
 
@@ -711,20 +711,20 @@ MarkLogicClient.prototype.endpointCaller =function endpointCaller(endpointDeclar
 };
 
 function initClient(client, inputParams) {
-  var connectionParams = {};
-  var isSSL = (inputParams.ssl == null) ? false : inputParams.ssl;
+  const connectionParams = {};
+  let isSSL = (inputParams.ssl == null) ? false : inputParams.ssl;
   if(inputParams.authType && inputParams.authType.toString().toLowerCase() === 'cloud' && !isSSL){
     isSSL = true;
   }
-  var keys = ['host', 'port', 'database', 'user', 'password', 'authType', 'token', 'basePath','apiKey','accessTokenDuration',
+  const keys = ['host', 'port', 'database', 'user', 'password', 'authType', 'token', 'basePath','apiKey','accessTokenDuration',
   'enableGzippedResponses', 'oauthToken'];
   if(isSSL) {
     keys.push('ca', 'cert', 'ciphers', 'clientCertEngine', 'crl', 'dhparam', 'ecdhCurve', 'honorCipherOrder', 'key', 'passphrase',
         'pfx', 'rejectUnauthorized', 'secureOptions', 'secureProtocol', 'servername', 'sessionIdContext', 'highWaterMark');
   }
-  for (var i=0; i < keys.length; i++) {
-    var key = keys[i];
-    var value = inputParams[key];
+  for (let i=0; i < keys.length; i++) {
+    const key = keys[i];
+    const value = inputParams[key];
     if (value != null) {
       connectionParams[key] = value;
     } else if (key === 'host') {
@@ -771,8 +771,8 @@ function initClient(client, inputParams) {
       connectionParams.user+':'+connectionParams.password;
   }
 
-  var noAgent = (inputParams.agent == null);
-  var agentOptions = noAgent ? {
+  const noAgent = (inputParams.agent == null);
+  const agentOptions = noAgent ? {
     keepAlive: true
   } : null;
   if (isSSL) {
@@ -799,7 +799,7 @@ function initClient(client, inputParams) {
   client.internal = new internal.InternalClass(client);
 }
 function releaseClient(client) {
-  var agent = client.connectionParams.agent;
+  const agent = client.connectionParams.agent;
   if (agent == null){
     return;
   }
diff --git a/lib/mllog.js b/lib/mllog.js
index e1fd65f1..6e013356 100644
--- a/lib/mllog.js
+++ b/lib/mllog.js
@@ -2,7 +2,7 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var util = require('util');
+const util = require('util');
 
 
 
diff --git a/lib/mlutil.js b/lib/mlutil.js
index 46d1b03f..e5b453be 100644
--- a/lib/mlutil.js
+++ b/lib/mlutil.js
@@ -2,13 +2,13 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var util = require('util');
+const util = require('util');
 
-var multipartBoundary = 'MLBOUND_' + Date.UTC(2014,12,31);
+const multipartBoundary = 'MLBOUND_' + Date.UTC(2014,12,31);
 
 // Normalize arguments by returning them as an array.
 function asArray() {
-  var argLen = arguments.length;
+  const argLen = arguments.length;
   switch(argLen) {
   // No arguments returns an empty array
   case 0:
@@ -24,22 +24,22 @@ function asArray() {
   // List of arguments returns an array with arguments as elements
   default:
     var args = new Array(argLen);
-    for(var i=0; i < argLen; ++i) {
+    for(let i=0; i < argLen; ++i) {
       args[i] = arguments[i];
     }
     return args;
   }
 }
 function copyProperties(source, target, srcKeys) {
-  var dest    = (arguments.length > 1) ? target  : {};
-  var isNamed = Array.isArray(srcKeys);
-  var keys    = isNamed ? srcKeys : Object.keys(source);
+  const dest    = (arguments.length > 1) ? target  : {};
+  const isNamed = Array.isArray(srcKeys);
+  const keys    = isNamed ? srcKeys : Object.keys(source);
 
   // for...in not currently optimized by v8
-  var keyLen = keys.length;
-  for (var i=0; i < keyLen; i++) {
-    var key = keys[i];
-    var val = source[key];
+  const keyLen = keys.length;
+  for (let i=0; i < keyLen; i++) {
+    const key = keys[i];
+    const val = source[key];
     if (!isNamed || (val !== void 0 && val !== null)) {
       dest[key] = val;
     }
@@ -64,7 +64,7 @@ function appendItem(object, key, value) {
     return;
   }
 
-  var array = object[key];
+  const array = object[key];
   if (array === void 0) {
     object[key] = [value];
   } else {
@@ -86,8 +86,8 @@ function MarkLogicError(firstArg, secondArg) {
     return new MarkLogicError(firstArg, secondArg);
   }
 
-  var name    = null;
-  var message = null;
+  let name    = null;
+  let message = null;
   if (firstArg == null) {
     message = 'unknown error';
   } else if (secondArg == null) {
@@ -108,8 +108,8 @@ function MarkLogicError(firstArg, secondArg) {
 util.inherits(MarkLogicError, Error);
 
 function callbackOn(object, method) {
-  var self = object;
-  var func = method;
+  const self = object;
+  const func = method;
   return function callBackMethod() {
     return func.apply(self, arguments);
   };
@@ -127,8 +127,8 @@ function endpointTransform(transform) {
         var endpointParam = 'transform='+encodeURIComponent(transform[0]);
         var transformParams = transform[1];
         var transformKeys = Object.keys(transformParams);
-        for (var i=0; i < transformKeys.length; i++) {
-          var transformKey = transformKeys[i];
+        for (let i=0; i < transformKeys.length; i++) {
+          const transformKey = transformKeys[i];
           endpointParam += '&trans:'+encodeURIComponent(transformKey)+'='+
             encodeURIComponent(transformParams[transformKey]);
         }
@@ -142,7 +142,7 @@ function endpointTransform(transform) {
 
 function newRequestOptions(connectionParams, endpoint, method) {
   const requestOptions = copyProperties(connectionParams);
-  let database = connectionParams.database;
+  const database = connectionParams.database;
   if(connectionParams.basePath) {
     const basePath = connectionParams.basePath.toString();
     let fixedBasePath = (connectionParams.host.toString().endsWith('/') && basePath.startsWith('/')) ? basePath.substring(1):basePath;
@@ -166,14 +166,14 @@ function newRequestOptions(connectionParams, endpoint, method) {
 }
 
 function extension(filename) {
-  var extStart = filename.lastIndexOf('.') + 1;
+  const extStart = filename.lastIndexOf('.') + 1;
   if (extStart === 0 || extStart === filename.length) {
     return null;
   }
   return filename.substring(extStart);
 }
 function rootname(filename) {
-  var extStart = filename.lastIndexOf('.');
+  const extStart = filename.lastIndexOf('.');
   if (extStart === 0 || extStart === filename.length) {
     return null;
   }
@@ -187,7 +187,7 @@ function identify(arg, withValues) {
   if (arg === null) {
     return 'null';
   }
-  var typed = typeof arg;
+  const typed = typeof arg;
   switch(typed) {
   case 'boolean'  : return withValues ? typed+' '+arg : typed;
   case 'function' : return typed;
@@ -296,7 +296,7 @@ function Transaction(id, cookies) {
 
   this.txid = id;
   if (Array.isArray(cookies) && cookies.length > 0) {
-    for (var i=0; i < cookies.length; i++) {
+    for (let i=0; i < cookies.length; i++) {
       cookies[i] = cookies[i].replace(/;\s*expires\s*=[^;]+(;|$)/i, '$1');
     }
     this.cookies = cookies;
@@ -329,9 +329,9 @@ function getTxidParam(txid, action) {
 }
 function addTxidHeaders(requestOptions, txid) {
   if (txid instanceof Transaction) {
-    var cookies = txid.cookies;
+    const cookies = txid.cookies;
     if (cookies != null) {
-      var headers = requestOptions.headers;
+      const headers = requestOptions.headers;
       if (headers != null) {
         headers.cookie = cookies;
       } else {
@@ -358,22 +358,22 @@ function Timestamp(value) {
 }
 
 // Slice mode can be 'array' or 'legacy'
-var sliceMode = 'array';
+let sliceMode = 'array';
 function setSliceMode(mode) {
   sliceMode = mode;
 }
 
 function makeSliceClause(variant, args) {
-  var argLen = args.length;
+  const argLen = args.length;
 
-  var sliceClause = {};
+  const sliceClause = {};
 
-  var firstArg  = null;
-  var secondArg = null;
+  let firstArg  = null;
+  let secondArg = null;
 
-  var argMax = Math.min(argLen, ((variant === 'query') ? 5 : 3));
-  var arg    = null;
-  for (var i=0; i < argMax; i++) {
+  const argMax = Math.min(argLen, ((variant === 'query') ? 5 : 3));
+  let arg    = null;
+  for (let i=0; i < argMax; i++) {
     arg = args[i];
     if (typeof arg === 'number' || arg instanceof Number) {
       switch(i) {
@@ -410,7 +410,7 @@ function makeSliceClause(variant, args) {
   }
 
   if (firstArg !== null && secondArg !== 0) {
-    var pageStart = (sliceMode === 'legacy') ? firstArg : firstArg + 1;
+    const pageStart = (sliceMode === 'legacy') ? firstArg : firstArg + 1;
     if (pageStart === 0 && secondArg === null) {
       sliceClause['page-length'] = 0;
     } else {
diff --git a/lib/operation.js b/lib/operation.js
index 68ab3066..9f439202 100644
--- a/lib/operation.js
+++ b/lib/operation.js
@@ -3,7 +3,7 @@
 */
 'use strict';
 
-var mlutil   = require('./mlutil.js');
+const mlutil   = require('./mlutil.js');
 
 function Operation(name, client, options, requestType, responseType) {
   if (!(this instanceof Operation)) {
@@ -48,11 +48,11 @@ Operation.prototype.STREAM_MODES_CHUNKED_OBJECT_SEQUENCE =
 Operation.prototype.emptyHeaderData = function emptyHeaderData(
     response
     ) {
-  var operation = this;
+  const operation = this;
 
-  var outputTransform = operation.outputTransform;
+  const outputTransform = operation.outputTransform;
   if (outputTransform != null) {
-    var responseHeaders = operation.responseHeaders;
+    let responseHeaders = operation.responseHeaders;
     if (responseHeaders == null) {
       operation.copyResponseHeaders(response);
       responseHeaders = operation.responseHeaders;
@@ -66,16 +66,16 @@ Operation.prototype.emptyHeaderData = function emptyHeaderData(
   return null;
 };
 Operation.prototype.collectBodyObject = function collectBodyObject(data) {
-  var operation = this;
+  const operation = this;
 
-  var outputTransform    = operation.outputTransform;
-  var hasOutputTransform = (outputTransform != null);
+  const outputTransform    = operation.outputTransform;
+  const hasOutputTransform = (outputTransform != null);
 
-  var headers = operation.responseHeaders;
+  const headers = operation.responseHeaders;
 
-  var bodyObject = mlutil.unmarshal(headers.format, data);
+  let bodyObject = mlutil.unmarshal(headers.format, data);
   if (bodyObject !== null) {
-    var subdata = operation.subdata;
+    const subdata = operation.subdata;
     if (Array.isArray(subdata)) {
       bodyObject = projectData(bodyObject, subdata, 0);
     }
@@ -98,25 +98,25 @@ Operation.prototype.collectBodyObject = function collectBodyObject(data) {
 Operation.prototype.makeObject = function makeObject(
     data, rawHeaderQueue
     ) {
-  var operation = this;
+  const operation = this;
 
-  var outputTransform = operation.outputTransform;
-  var partObject = null;
+  const outputTransform = operation.outputTransform;
+  let partObject = null;
 
   // Get corresponding multipart header for part
-  var partRawHeaders = rawHeaderQueue.pollFirst();
-  var partHeaders = parsePartHeaders(partRawHeaders);
-  var partUri = partHeaders.uri;
+  const partRawHeaders = rawHeaderQueue.pollFirst();
+  const partHeaders = parsePartHeaders(partRawHeaders);
+  const partUri = partHeaders.uri;
 
-  var isInline = (partUri == null && !partHeaders.kind);
-  var isMetadata = (
+  const isInline = (partUri == null && !partHeaders.kind);
+  const isMetadata = (
       !isInline &&
       (partHeaders.category != null) &&
       partHeaders.category !== 'content'
     );
 
   // Convert buffer data to object
-  var partData = mlutil.unmarshal(partHeaders.format, data);
+  const partData = mlutil.unmarshal(partHeaders.format, data);
 
   // Inline case
   if (isInline) {
@@ -135,7 +135,7 @@ Operation.prototype.makeObject = function makeObject(
   else if (isMetadata) {
     operation.logger.debug('parsed metadata for %s', partUri);
     if (this.nextMetadataBuffer !== null) {
-      var metadataHeaders = this.nextMetadataBuffer[0];
+      const metadataHeaders = this.nextMetadataBuffer[0];
       mlutil.copyProperties(this.nextMetadataBuffer[1], metadataHeaders);
       partObject = metadataHeaders;
     }
@@ -156,7 +156,7 @@ Operation.prototype.makeObject = function makeObject(
 
   if (partObject !== null) {
     // Subdata processing (poor man's XPath)
-    var subdata = operation.subdata;
+    const subdata = operation.subdata;
     if (Array.isArray(subdata)) {
       partObject = projectData(partObject, subdata, 0);
     }
@@ -171,16 +171,16 @@ Operation.prototype.makeObject = function makeObject(
   return partObject;
 };
 Operation.prototype.dispatchError = function dispatchError(error) {
-  var operation = this;
+  const operation = this;
 
-  var input =
+  const input =
     (error == null) ? operation.makeError('unknown error') :
     (typeof error === 'string' || error instanceof String)          ? operation.makeError(error) :
     error;
 
-  var outputStream = operation.outputStream;
+  const outputStream = operation.outputStream;
   if (outputStream != null) {
-    var errorListeners = outputStream.listeners('error');
+    const errorListeners = outputStream.listeners('error');
     if (Array.isArray(errorListeners) && errorListeners.length > 0) {
       outputStream.emit('error', input);
     } else {
@@ -193,7 +193,7 @@ Operation.prototype.dispatchError = function dispatchError(error) {
   }
 };
 Operation.prototype.logError = function logError(error) {
-  var operation = this;
+  const operation = this;
 
   if (error.body == null) {
     operation.logger.error(error.message);
@@ -204,13 +204,13 @@ Operation.prototype.logError = function logError(error) {
   }
 };
 Operation.prototype.makeError = function makeError(message) {
-  var operation = this;
+  const operation = this;
 
-  var operationName = operation.name;
-  var operationMsg  = (operationName === void 0) ? message :
+  const operationName = operation.name;
+  let operationMsg  = (operationName === void 0) ? message :
     (operationName+': '+message);
 
-  var errorTransform = operation.errorTransform;
+  const errorTransform = operation.errorTransform;
   const responsePath = operation.options.path;
   const subMsg = (responsePath && responsePath.toString().includes('?'))?
       responsePath.toString().substring(0,responsePath.toString().indexOf('?') ):
@@ -222,13 +222,13 @@ Operation.prototype.makeError = function makeError(message) {
     );
 };
 Operation.prototype.copyResponseHeaders = function copyResponseHeaders(response) {
-  var operation = this;
+  const operation = this;
 
-  var responseHeaders = response.headers;
+  const responseHeaders = response.headers;
 
-  var contentType = trimContentType(responseHeaders['content-type']);
+  const contentType = trimContentType(responseHeaders['content-type']);
 
-  var format = responseHeaders['vnd.marklogic.document-format'];
+  let format = responseHeaders['vnd.marklogic.document-format'];
   if ((format == null) && contentType !== null) {
     format = contentTypeToFormat(contentType);
   }
@@ -267,8 +267,8 @@ function OperationHeaders(
   if (versionId == null) {
     this.versionId = null;
   } else {
-    var firstChar = versionId.charAt(0);
-    var lastChar  = versionId.charAt(versionId.length - 1);
+    const firstChar = versionId.charAt(0);
+    const lastChar  = versionId.charAt(versionId.length - 1);
     this.versionId = (
         (firstChar === '"' && lastChar === '"') ||
         (firstChar === '\'' && lastChar === '\'')
@@ -283,7 +283,7 @@ function trimContentType(contentType) {
   if (contentType == null) {
     return null;
   }
-  var semicolonPos = contentType.indexOf(';');
+  const semicolonPos = contentType.indexOf(';');
   return (semicolonPos > 0) ?
     contentType.substring(0, semicolonPos) : contentType;
 }
@@ -292,7 +292,7 @@ function contentTypeToFormat(contentType) {
     return null;
   }
 
-  var fields = contentType.split(/[\/+]/);
+  const fields = contentType.split(/[\/+]/);
   switch(fields[0]) {
   case 'application':
     switch(fields[fields.length - 1]) {
@@ -326,21 +326,21 @@ function contentTypeToFormat(contentType) {
 }
 
 function parsePartHeaders(headers) {
-  var partHeaders = {};
+  const partHeaders = {};
 
-  var contentDispositionArray = headers['content-disposition'];
+  const contentDispositionArray = headers['content-disposition'];
   if (Array.isArray(contentDispositionArray) &&
       contentDispositionArray.length > 0) {
-    var contentDisposition = contentDispositionArray[0];
+    let contentDisposition = contentDispositionArray[0];
     if (contentDisposition.substring(contentDisposition.length) !== ';') {
       contentDisposition += ';';
     }
 
-    var tokens = contentDisposition.match(/"[^"]*"|;|=|[^";=\s]+/g);
-    var key   = null;
-    var value = null;
-    for (var i=0; i < tokens.length; i++) {
-      var token = tokens[i];
+    const tokens = contentDisposition.match(/"[^"]*"|;|=|[^";=\s]+/g);
+    let key   = null;
+    let value = null;
+    for (let i=0; i < tokens.length; i++) {
+      const token = tokens[i];
       switch(token) {
       case ';':
         if (key) {
@@ -350,7 +350,7 @@ function parsePartHeaders(headers) {
               value = value.substring(1,value.length - 1);
             }
 
-            var currentValue = partHeaders[key];
+            const currentValue = partHeaders[key];
             if (!currentValue) {
               partHeaders[key] = value;
             } else if (currentValue instanceof Array) {
@@ -378,8 +378,8 @@ function parsePartHeaders(headers) {
     }
   }
 
-  var contentTypeArray = headers['content-type'];
-  var contentType = null;
+  const contentTypeArray = headers['content-type'];
+  let contentType = null;
   if (Array.isArray(contentTypeArray) && contentTypeArray.length > 0) {
     contentType             = trimContentType(contentTypeArray[0]);
     partHeaders.contentType = contentType;
@@ -389,12 +389,12 @@ function parsePartHeaders(headers) {
     partHeaders.format = contentTypeToFormat(contentType);
   }
 
-  var contentLengthArray = headers['content-length'];
+  const contentLengthArray = headers['content-length'];
   if (Array.isArray(contentLengthArray) && contentLengthArray.length > 0) {
     partHeaders.contentLength = contentLengthArray[0];
   }
 
-  var contentIdArray = headers['content-id'];
+  const contentIdArray = headers['content-id'];
   if (Array.isArray(contentIdArray) && contentIdArray.length > 0) {
     partHeaders.contentId = contentIdArray[0].slice(1, -1);
   }
@@ -407,19 +407,19 @@ function projectData(data, subdata, i) {
     return data;
   }
 
-  var key = subdata[i];
+  const key = subdata[i];
   if (!Array.isArray(data)) {
-    var nextData = data[key];
+    const nextData = data[key];
     if (nextData == null) {
       return data;
     }
     return projectData(nextData, subdata, i + 1);
   }
 
-  var newData = [];
-  for (var j=0; j < data.length; j++) {
-    var currItem  = data[j];
-    var nextValue = currItem[key];
+  const newData = [];
+  for (let j=0; j < data.length; j++) {
+    const currItem  = data[j];
+    const nextValue = currItem[key];
     newData.push(
         (nextValue == null) ? currItem :
           projectData(nextValue, subdata, i + 1)
diff --git a/lib/optional.js b/lib/optional.js
index 2c66000e..228c9234 100644
--- a/lib/optional.js
+++ b/lib/optional.js
@@ -14,7 +14,7 @@ function library(libname) {
   }
 }
 function libraryProperty(libname, propertyName) {
-  var lib = library(libname);
+  const lib = library(libname);
   if (lib == null) {
     return null;
   }
diff --git a/lib/patch-builder.js b/lib/patch-builder.js
index 673ef102..f70b78a1 100644
--- a/lib/patch-builder.js
+++ b/lib/patch-builder.js
@@ -4,9 +4,9 @@
 'use strict';
 
 
-var mlutil   = require('./mlutil.js');
+const mlutil   = require('./mlutil.js');
 
-var qb = require('./query-builder.js');
+const qb = require('./query-builder.js');
 
 /**
  * A helper for building the definition of a document patch. The helper is
@@ -33,12 +33,12 @@ var qb = require('./query-builder.js');
  * @returns {patchBuilder.PatchOperation} a patch operation
  */
 function remove() {
-  var select      = null;
-  var cardinality = null;
+  let select      = null;
+  let cardinality = null;
 
-  var argLen = arguments.length;
-  for (var i=0; i < argLen; i++) {
-    var arg = arguments[i];
+  const argLen = arguments.length;
+  for (let i=0; i < argLen; i++) {
+    const arg = arguments[i];
     if (i === 0) {
       select = arg;
       continue;
@@ -54,7 +54,7 @@ function remove() {
     throw new Error('remove takes select and optional cardinality');
   }
 
-  var operation = {
+  const operation = {
     select: select
   };
   if (cardinality !== null) {
@@ -80,14 +80,14 @@ function remove() {
  * @returns {patchBuilder.PatchOperation} a patch operation
  */
 function insert() {
-  var context     = null;
-  var position    = null;
-  var content     = void 0;
-  var cardinality = null;
-
-  var argLen = arguments.length;
-  for (var i=0; i < argLen; i++) {
-    var arg = arguments[i];
+  let context     = null;
+  let position    = null;
+  let content     = void 0;
+  let cardinality = null;
+
+  const argLen = arguments.length;
+  for (let i=0; i < argLen; i++) {
+    const arg = arguments[i];
     if (i === 0) {
       context = arg;
       continue;
@@ -96,7 +96,7 @@ function insert() {
       content = arg;
       continue;
     }
-    var isString = (typeof arg === 'string' || arg instanceof String);
+    const isString = (typeof arg === 'string' || arg instanceof String);
     if (isString) {
       if (position === null && /^(before|after|last-child)$/.test(arg)) {
         position = arg;
@@ -120,7 +120,7 @@ function insert() {
         );
   }
 
-  var operation = {
+  const operation = {
     context:  context,
     position: position,
     content:  content
@@ -158,11 +158,11 @@ function library(module) {
         );
   }
 
-  var rootname = mlutil.rootname(module);
+  const rootname = mlutil.rootname(module);
   if (rootname === null) {
     throw new Error('library must have an extension of .sjs or .xqy');
   }
-  var extension = module.substring((module.lastIndexOf('.')+1), module.length);
+  const extension = module.substring((module.lastIndexOf('.')+1), module.length);
 
   if(extension === 'sjs') {
     return {'replace-library':{
@@ -195,9 +195,9 @@ function library(module) {
  * @returns {patchBuilder.ApplyDefinition} the specification for applying a function
  */
 function apply() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
-  var argLen = args.length;
+  const argLen = args.length;
   switch(argLen) {
   case 0:
     throw new Error('no name for function to apply');
@@ -412,14 +412,14 @@ function replaceRegex(match, replace, flags) {
  * @returns {patchBuilder.PatchOperation} a patch operation
  */
 function replace() {
-  var select      = null;
-  var content     = void 0;
-  var cardinality = null;
-  var apply       = null;
-
-  var argLen = arguments.length;
-  for (var i=0; i < argLen; i++) {
-    var arg = arguments[i];
+  let select      = null;
+  let content     = void 0;
+  let cardinality = null;
+  let apply       = null;
+
+  const argLen = arguments.length;
+  for (let i=0; i < argLen; i++) {
+    const arg = arguments[i];
     if (i === 0) {
       select = arg;
       continue;
@@ -428,7 +428,7 @@ function replace() {
       content = arg;
       continue;
     }
-    var isString = (typeof arg === 'string' || arg instanceof String);
+    const isString = (typeof arg === 'string' || arg instanceof String);
     if (isString && cardinality === null && /^[?.*+]$/.test(arg)) {
       cardinality = arg;
       continue;
@@ -455,7 +455,7 @@ function replace() {
         );
   }
 
-  var operation = {
+  const operation = {
     select:  select,
     content: content
   };
@@ -493,16 +493,16 @@ function replace() {
  * @returns {patchBuilder.PatchOperation} a patch operation
  */
 function replaceInsert() {
-  var select      = null;
-  var context     = null;
-  var position    = null;
-  var content     = void 0;
-  var cardinality = null;
-  var apply       = null;
-
-  var argLen = arguments.length;
-  for (var i=0; i < argLen; i++) {
-    var arg = arguments[i];
+  let select      = null;
+  let context     = null;
+  let position    = null;
+  let content     = void 0;
+  let cardinality = null;
+  let apply       = null;
+
+  const argLen = arguments.length;
+  for (let i=0; i < argLen; i++) {
+    const arg = arguments[i];
     if (i === 0) {
       select = arg;
       continue;
@@ -515,7 +515,7 @@ function replaceInsert() {
       content = arg;
       continue;
     }
-    var isString = (typeof arg === 'string' || arg instanceof String);
+    const isString = (typeof arg === 'string' || arg instanceof String);
     if (isString) {
       if (position === null && /^(before|after|last-child)$/.test(arg)) {
         position = arg;
@@ -547,7 +547,7 @@ function replaceInsert() {
         );
   }
 
-  var operation = {
+  const operation = {
     select:   select,
     context:  context,
     position: position,
@@ -583,7 +583,7 @@ function replaceInsert() {
  * @returns {patchBuilder.PathLanguageParam} the specification for the path language
  */
 function pathLanguage() {
-  var pathlang = (arguments.length < 1) ? null : arguments[0];
+  const pathlang = (arguments.length < 1) ? null : arguments[0];
   if (pathlang !== 'jsonpath' && pathlang !== 'xpath') {
     throw new Error(
         'pathLanguage takes a path language of xpath or jsonpath'
@@ -642,7 +642,7 @@ function removeCollection(collection) {
  * @returns {patchBuilder.PatchOperation} a patch operation
  */
 function addPermission() {
-  var permission = getPermission(
+  const permission = getPermission(
       mlutil.asArray.apply(null, arguments)
       );
   if (permission === null) {
@@ -662,7 +662,7 @@ function addPermission() {
  * capabilities from the insert|update|read|execute enumeration
  */
 function replacePermission() {
-  var permission = getPermission(
+  const permission = getPermission(
       mlutil.asArray.apply(null, arguments)
       );
   if (permission === null) {
@@ -688,13 +688,13 @@ function removePermission(roleName) {
 }
 /** @ignore */
 function getPermission(args) {
-  var argLen = args.length;
+  const argLen = args.length;
 
-  var roleName     = null;
-  var capabilities = null;
-  var isObject     = false;
+  let roleName     = null;
+  let capabilities = null;
+  let isObject     = false;
 
-  var first = (argLen === 0) ? null : args[0];
+  const first = (argLen === 0) ? null : args[0];
   if (first !== null) {
     if (args.length > 1 && typeof first === 'string') {
       roleName = first;
@@ -713,10 +713,10 @@ function getPermission(args) {
     return null;
   }
 
-  var check = {execute:true, insert:true, read:true, update:true};
+  const check = {execute:true, insert:true, read:true, update:true};
   if (Array.isArray(capabilities)) {
-    var max = capabilities.length;
-    for (var i=0; i < max; i++) {
+    const max = capabilities.length;
+    for (let i=0; i < max; i++) {
       if (!check[capabilities[i]]) {
         return null;
       }
@@ -754,7 +754,7 @@ function addProperty(name, value) {
   if (typeof name !== 'string' || value == null) {
     throw new Error('properties.add() takes a string name and a value');
   }
-  var prop = {};
+  const prop = {};
   prop[name] = value;
   return insert('/object-node("properties")', 'last-child', prop);
 }
@@ -822,7 +822,7 @@ function addMetadataValue(name, value) {
   if (typeof name !== 'string' || typeof value !== 'string' ) {
     throw new Error('metadataValues.add() takes a string name and string value');
   }
-  var metaVal = {};
+  const metaVal = {};
   metaVal[name] = value;
   return insert('/object-node("metadataValues")', 'last-child', metaVal);
 }
diff --git a/lib/plan-builder-base.js b/lib/plan-builder-base.js
index 70e3a791..cbeb9149 100644
--- a/lib/plan-builder-base.js
+++ b/lib/plan-builder-base.js
@@ -261,11 +261,11 @@ function castArg(arg, funcName, paramName, argPos, paramTypes) {
                   );
                 }
                 if(key === 'permissions'){
-                  let permissionValue = [];
+                  const permissionValue = [];
                   for(let i=0; i<value.length; i++){
                     if(value[i].hasOwnProperty('role-name')){
                       for(let j=0; (value[i].capabilities && j<value[i].capabilities.length); j++){
-                        let tempValue = {};
+                        const tempValue = {};
                         tempValue.roleName=value[i]['role-name'];
                         tempValue.capability = value[i].capabilities[j];
                         permissionValue.push(tempValue);
diff --git a/lib/query-builder.js b/lib/query-builder.js
index 65808297..08fc1f7b 100644
--- a/lib/query-builder.js
+++ b/lib/query-builder.js
@@ -2,14 +2,14 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var util     = require('util');
+const util     = require('util');
 
-var mlutil   = require('./mlutil.js');
+const mlutil   = require('./mlutil.js');
 
 const types    = require('./server-types-generated.js');
 const bldrbase = require('./plan-builder-base.js');
 
-var comparisons = {
+const comparisons = {
     '<'  : 'LT',
     '<=' : 'LE',
     '>'  : 'GT',
@@ -17,7 +17,7 @@ var comparisons = {
     '='  : 'EQ',
     '!=' : 'NE'
 };
-var datatypes = {
+const datatypes = {
     'xs:anyURI':            'xs:anyURI',
     'xs:date':              'xs:date',
     'xs:dateTime':          'xs:dateTime',
@@ -44,7 +44,7 @@ function asIndex(index) {
 }
 /** @ignore */
 function addIndex(query, index, isContainer) {
-  var containerOnly = (isContainer || false);
+  const containerOnly = (isContainer || false);
   if (index instanceof JSONPropertyDef) {
     query['json-property'] = index['json-property'];
   } else if (index instanceof ElementDef) {
@@ -111,12 +111,12 @@ function checkQueryArray(queryArray) {
     return queryArray;
   }
 
-  var max = queryArray.length;
+  const max = queryArray.length;
   if (max === 0) {
     return queryArray;
   }
 
-  var i = 0;
+  let i = 0;
   for (; i < max; i++) {
     checkQuery(queryArray[i]);
   }
@@ -170,11 +170,11 @@ function ConstraintDef() {
  * @returns {queryBuilder.Query} a composable query
  */
 function and() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var queries = [];
-  var ordered = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  const args = mlutil.asArray.apply(null, arguments);
+  const queries = [];
+  let ordered = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (ordered === null) {
       if (arg instanceof OrderedDef) {
@@ -260,7 +260,7 @@ function QueryListDef(queries, ordered, weight, distance) {
  * @returns {queryBuilder.Query} a composable query
  */
 function andNot() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing positive and negative queries');
@@ -316,7 +316,7 @@ function PositiveNegativeDef(positive, negative) {
  * @returns {queryBuilder.IndexedName} an indexed name for specifying a query
  */
 function attribute() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing element and attribute');
@@ -393,7 +393,7 @@ function AttributeDef(elemQName, attrQName) {
  * @returns {queryBuilder.Query} a composable query
  */
 function boost() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing matching and boosting queries');
@@ -451,7 +451,7 @@ function MatchingBoostingDef(matching, boosting) {
  * @returns {queryBuilder.Region} the region criteria for a geospatial query
  */
 function box() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing four corners for box');
@@ -497,8 +497,8 @@ function BoxRegionDef(box) {
  * @returns {queryBuilder.Region} the region criteria for a geospatial query
  */
 function circle() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var arg = null;
+  const args = mlutil.asArray.apply(null, arguments);
+  let arg = null;
   switch(args.length) {
   case 0:
     throw new Error('missing radius and center for circle');
@@ -582,18 +582,18 @@ function CircleDef(radius, center) {
  * @returns {queryBuilder.Query} a composable query
  */
 function collection() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
   if (argLen === 0) {
     return new CollectionConstraintDef(null, null, null);
   }
 
-  var constraintName = null;
-  var suggestOptions = null;
-  var prefix = null;
-  var arg = null;
-  var i = 0;
+  let constraintName = null;
+  let suggestOptions = null;
+  let prefix = null;
+  let arg = null;
+  let i = 0;
   for (; i < argLen; i++) {
     arg = args[i];
     if (constraintName === null && arg instanceof BindDef) {
@@ -699,18 +699,18 @@ util.inherits(CollectionQueryDef, QueryDef);
  * @returns {queryBuilder.Query} a composable query
  */
 function lsqtQuery() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('no temporal collection for lsqt query');
   }
 
-  var temporalCollection = null;
-  var weight = null;
-  var timestamp = null;
-  var temporalOptions = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  let temporalCollection = null;
+  let weight = null;
+  let timestamp = null;
+  let temporalOptions = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
       if (typeof arg !== 'string' && !(arg instanceof String)) {
@@ -810,17 +810,17 @@ function LSQTQueryDef(temporalCollection, weight, timestamp, temporalOptions) {
  * @returns {queryBuilder.Query} a composable query
  */
 function scope() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 1) {
     throw new Error('element or property scope not specified');
   }
 
-  var index = null;
-  var constraintName = null;
-  var fragmentScope = null;
-  var query = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  let index = null;
+  let constraintName = null;
+  let fragmentScope = null;
+  let query = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
       index = asIndex(arg);
@@ -918,9 +918,9 @@ function ContainedDef(index, fragmentScope, query) {
     this['fragment-scope'] = fragmentScope;
   }
   if (query != null) {
-    var queryKeys = Object.keys(query);
-    var queryKey = null;
-    for (var i=0; i < queryKeys.length; i++) {
+    const queryKeys = Object.keys(query);
+    let queryKey = null;
+    for (let i=0; i < queryKeys.length; i++) {
       queryKey = queryKeys[i];
       this[queryKey] = query[queryKey];
     }
@@ -943,7 +943,7 @@ function ContainedDef(index, fragmentScope, query) {
  * @returns {queryBuilder.DatatypeParam} a datatype specification
  */
 function datatype() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing datatype');
@@ -987,12 +987,12 @@ function DatatypeDef(datatype, collation) {
  * @returns {queryBuilder.Query} a composable query
  */
 function directory() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
-  var uris = [];
-  var infinite = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  const uris = [];
+  let infinite = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (infinite === null && (typeof arg === 'boolean')) {
       infinite = arg;
@@ -1105,7 +1105,7 @@ util.inherits(DocumentFragmentDef, QueryDef);
  * @returns {queryBuilder.IndexedName} an indexed name for specifying a query
  */
 function element() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing element name');
@@ -1144,7 +1144,7 @@ function ElementDef(qname) {
  * @returns {queryBuilder.IndexedName} an indexed name for specifying a query
  */
 function field() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing field name');
@@ -1239,18 +1239,18 @@ function FragmentScopeDef(scope) {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoAttributePair() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 2) {
     throw new Error('need at least two parameters for geospatial attribute pair query');
   }
 
-  var location = {};
+  const location = {};
 
-  var keys = ['parent', 'lat', 'lon'];
-  var iArg=0;
-  for (var i=0; i < keys.length; i++) {
-    var key = keys[i];
-    var arg = args[iArg++];
+  const keys = ['parent', 'lat', 'lon'];
+  let iArg=0;
+  for (let i=0; i < keys.length; i++) {
+    const key = keys[i];
+    const arg = args[iArg++];
     if (arg instanceof QNameDef) {
       location[key] = arg;
     } else if (typeof arg === 'string' || arg instanceof String) {
@@ -1284,19 +1284,19 @@ function geoAttributePair() {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoElement() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('need at least one parameter for geospatial element query');
   }
 
-  var location = {};
+  const location = {};
 
 // TODO: elementName
-  var maxIndex = Math.min(argLen, 2);
-  var elemName = null;
-  var arg = null;
-  var i=0;
+  const maxIndex = Math.min(argLen, 2);
+  let elemName = null;
+  let arg = null;
+  let i=0;
   while (i < maxIndex) {
     arg = args[i];
     if (arg instanceof QNameDef) {
@@ -1336,17 +1336,17 @@ function geoElement() {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoElementPair() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 2) {
     throw new Error('need at least two parameters for geospatial element pair query');
   }
 
-  var location = {};
+  const location = {};
 
-  var keys = ['parent', 'lat', 'lon'];
-  var key = null;
-  var arg = null;
-  for (var i=0; i < keys.length; i++) {
+  const keys = ['parent', 'lat', 'lon'];
+  let key = null;
+  let arg = null;
+  for (let i=0; i < keys.length; i++) {
     key = keys[i];
     arg = args[i];
     if (arg instanceof QNameDef) {
@@ -1375,18 +1375,18 @@ function geoElementPair() {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoProperty() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('need at least one parameters for geospatial property query');
   }
 
-  var location = {};
+  const location = {};
 
-  var maxIndex = Math.min(argLen, 2);
-  var propName = null;
-  var arg = null;
-  var i=0;
+  const maxIndex = Math.min(argLen, 2);
+  let propName = null;
+  let arg = null;
+  let i=0;
   while (i < maxIndex) {
     arg = args[i];
     if (arg instanceof JSONPropertyDef) {
@@ -1420,17 +1420,17 @@ function geoProperty() {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoPropertyPair() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 2) {
     throw new Error('need at least two parameters for geospatial property pair query');
   }
 
-  var location = {};
+  const location = {};
 
-  var keys = ['parent-property', 'lat-property', 'lon-property'];
-  var key = null;
-  var arg = null;
-  for (var i=0; i < keys.length; i++) {
+  const keys = ['parent-property', 'lat-property', 'lon-property'];
+  let key = null;
+  let arg = null;
+  for (let i=0; i < keys.length; i++) {
     key = keys[i];
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
@@ -1459,17 +1459,17 @@ function geoPropertyPair() {
  * @returns {queryBuilder.GeoLocation} the specification for the geospatial locations
  */
 function geoPath() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 1) {
     throw new Error('need at least one parameter for geospatial path query');
   }
 
-  var location = {};
+  const location = {};
 
-  var seekingPathIndex = true;
-  var firstArg = null;
-  var arg = null;
-  var i=0;
+  let seekingPathIndex = true;
+  let firstArg = null;
+  let arg = null;
+  let i=0;
   for (; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
@@ -1581,7 +1581,7 @@ function geospatialImpl(hasOperator, args) {
     throw new Error('need at least one parameter for geospatial query');
   }
 
-  var isGeoLocationIndex = {
+  const isGeoLocationIndex = {
     'geo-attr-pair':          true,
     'geo-elem':               true,
     'geo-elem-pair':          true,
@@ -1590,18 +1590,18 @@ function geospatialImpl(hasOperator, args) {
     'geo-path':               true
   };
 
-  var query = null;
-  var variant = null;
-  var constraintName = null;
-  var suggestOptions = null;
-  var seekingWeight = true;
-  var seekingFragmentScope = true;
-  var seekingGeoOption = true;
-  var seekingRegion = true;
-  var seekingGeoOperator = true;
-  var firstKey = null;
-  var arg = null;
-  var i=0;
+  let query = null;
+  let variant = null;
+  let constraintName = null;
+  let suggestOptions = null;
+  let seekingWeight = true;
+  let seekingFragmentScope = true;
+  let seekingGeoOption = true;
+  let seekingRegion = true;
+  let seekingGeoOperator = true;
+  let firstKey = null;
+  let arg = null;
+  let i=0;
   for (; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
@@ -1742,13 +1742,13 @@ util.inherits(GeospatialConstraintDef, ConstraintDef);
  * @returns {queryBuilder.HeatMapParam} the buckets for a geospatial facet
  */
 function heatmap() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('no region or divisions for heat map');
   }
 
-  var hmap = {};
+  const hmap = {};
   switch(argLen) {
   case 3:
     var first  = args[0];
@@ -1768,14 +1768,14 @@ function heatmap() {
     }
 
     var keys = ['s', 'w', 'n', 'e'];
-    for (var i=0; i < keys.length; i++) {
-      var key   = keys[i];
-      var value = region[key];
+    for (let i=0; i < keys.length; i++) {
+      const key   = keys[i];
+      let value = region[key];
       if (value != null) {
         hmap[key] = value;
         continue;
       } else {
-        var altKey = null;
+        let altKey = null;
         switch(key) {
         case 's':
           altKey = 'south';
@@ -1857,7 +1857,7 @@ function GeoOptionsDef(options) {
  * @returns {queryBuilder.LatLon} a coordinate for a {queryBuilder.Region}
  */
 function latlon() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing latitude and longitude for latlon coordinate');
@@ -1971,7 +1971,7 @@ function MinDistanceDef(distance) {
  * @returns {queryBuilder.Query} a composable query
  */
 function near() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 1) {
     throw new Error('need at least a subquery for near query');
   }
@@ -1983,14 +1983,14 @@ function NearDef(args) {
     return new NearDef(args);
   }
 
-  var query               = {};
-  var subquery            = [];
-  var seekingOrdered      = true;
-  var seekingWeight       = true;
-  var seekingDistance     = true;
-  var seekingMinDistance  = true;
-  var arg                 = null;
-  for (var i=0; i < args.length; i++) {
+  const query               = {};
+  const subquery            = [];
+  let seekingOrdered      = true;
+  let seekingWeight       = true;
+  let seekingDistance     = true;
+  let seekingMinDistance  = true;
+  let arg                 = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (seekingOrdered) {
       if (arg instanceof OrderedDef) {
@@ -2069,7 +2069,7 @@ util.inherits(NotDef, QueryDef);
  * @returns {queryBuilder.Query} a composable query
  */
 function notIn() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing positive and negative queries');
@@ -2163,7 +2163,7 @@ function OrderedDef(on) {
  * @returns {queryBuilder.IndexedName} an indexed name for specifying a query
  */
 function pathIndex() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing path for path index identifier');
@@ -2214,7 +2214,7 @@ function PathDef(pathExpression, namespaces) {
  * @returns {queryBuilder.CoordSystem} a coordinate system identifier
  */
 function coordSystem() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing identifier for coordinate system');
@@ -2249,7 +2249,7 @@ function CoordSystemDef(coordSystem) {
  * @returns {queryBuilder.Region} the region criteria for a geospatial query
  */
 function point() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing latitude and longitude for point');
@@ -2287,11 +2287,11 @@ function PointRegionDef(point) {
  * @returns {queryBuilder.Region} the region criteria for a geospatial query
  */
 function polygon() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
-  var points = [];
-  var arg = null;
-  var i=0;
+  const points = [];
+  let arg = null;
+  let i=0;
   for (; i < args.length; i++) {
     arg = args[i];
     if (arg instanceof PointRegionDef) {
@@ -2357,7 +2357,7 @@ util.inherits(PropertiesFragmentDef, QueryDef);
  * @returns {queryBuilder.IndexedName} an indexed name for specifying a query
  */
 function property() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing JSON property name');
@@ -2399,7 +2399,7 @@ function JSONPropertyDef(name) {
  * an element or attribute
  */
 function qname() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('missing name for QName identifier');
@@ -2450,8 +2450,8 @@ function QNameDef(ns, name) {
  * for a {@link queryBuilder#periodRange} temporal query
  */
 function period() {
-  var startDate = null;
-  var endDate   = null;
+  let startDate = null;
+  let endDate   = null;
 
   switch(arguments.length) {
   case 0:
@@ -2512,15 +2512,15 @@ function PeriodDef(startDate, endDate) {
  * @returns {queryBuilder.Query} a composable query
  */
 function periodCompare() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
-
-  var compareAxis1    = null;
-  var compareOperator = null;
-  var compareAxis2    = null;
-  var temporalOptions = null;
-  var arg = null;
-  for (var i=0; i < argLen; i++) {
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
+
+  let compareAxis1    = null;
+  let compareOperator = null;
+  let compareAxis2    = null;
+  let temporalOptions = null;
+  let arg = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       if (compareAxis1 === null) {
@@ -2612,15 +2612,15 @@ function PeriodCompareQueryDef(
  * @returns {queryBuilder.Query} a composable query
  */
 function periodRange() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
-
-  var rangeAxis       = null;
-  var rangeOperator   = null;
-  var rangePeriod     = null;
-  var temporalOptions = null;
-  var arg = null;
-  for (var i=0; i < argLen; i++) {
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
+
+  let rangeAxis       = null;
+  let rangeOperator   = null;
+  let rangePeriod     = null;
+  let temporalOptions = null;
+  let arg = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     if (Array.isArray(arg) && arg.length > 0) {
       if (rangeAxis === null && (typeof arg[0] === 'string' || arg[0] instanceof String)) {
@@ -2829,21 +2829,21 @@ function TemporalOptionsDef(options) {
  * @returns {queryBuilder.Query} a composable query
  */
 function range() {
-  var args = mlutil.asArray.apply(null, arguments);
-
-  var index = null;
-  var datatype = null;
-  var collation = null;
-  var weight = null;
-  var fragmentScope = null;
-  var rangeOptions = null;
-  var values = null;
-  var operator = null;
-  var suggestOptions = null;
-  var constraintName = null;
-  var defaultConstraint = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  const args = mlutil.asArray.apply(null, arguments);
+
+  let index = null;
+  let datatype = null;
+  let collation = null;
+  let weight = null;
+  let fragmentScope = null;
+  let rangeOptions = null;
+  let values = null;
+  let operator = null;
+  let suggestOptions = null;
+  let constraintName = null;
+  let defaultConstraint = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
       index = asIndex(arg);
@@ -2887,11 +2887,11 @@ function range() {
       continue;
     }
     if ((datatype === null || operator === null) && (typeof arg === 'string' || arg instanceof String)) {
-      var testType = (datatype === null) ? datatypes[arg.trim()] : null;
+      const testType = (datatype === null) ? datatypes[arg.trim()] : null;
       if (testType != null) {
         datatype = testType;
       } else {
-        var testComp = (operator === null) ? comparisons[arg.trim()] : null;
+        const testComp = (operator === null) ? comparisons[arg.trim()] : null;
         if (testComp != null) {
           operator = testComp;
         } else if (values === null) {
@@ -2909,7 +2909,7 @@ function range() {
     }
   }
 
-  var rangeDef = new RangeDef(
+  const rangeDef = new RangeDef(
       index, datatype, collation, operator, values, weight, rangeOptions, fragmentScope
   );
 
@@ -2933,7 +2933,7 @@ function range() {
     }
   }
 
-  var constraint = new RangeConstraintDef(constraintName, rangeDef, suggestOptions);
+  const constraint = new RangeConstraintDef(constraintName, rangeDef, suggestOptions);
 
   return (defaultConstraint !== true) ?
       constraint : new DefaultConstraintDef(constraint);
@@ -2976,7 +2976,7 @@ function RangeDef(
         );
   }
 
-  var hasOperator = (operator != null);
+  const hasOperator = (operator != null);
 
   if (index != null) {
     addIndex(this, index, false);
@@ -3060,8 +3060,8 @@ function RangeOptionsDef(options) {
  * @returns {object} the coordinates for the box
  */
 function southWestNorthEast() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen !== 4) {
     throw new Error('box must have four parameters: '+argLen);
   }
@@ -3119,12 +3119,12 @@ function BoxDef(south, west, north, east) {
  * @returns {queryBuilder.Query} a composable query
  */
 function term() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var text = [];
-  var weight = null;
-  var termOptions = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  const args = mlutil.asArray.apply(null, arguments);
+  const text = [];
+  let weight = null;
+  let termOptions = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (weight === null && arg instanceof WeightDef) {
       weight = arg.weight;
@@ -3165,7 +3165,7 @@ util.inherits(TermDef, QueryDef);
  * @returns {queryBuilder.Query} a composable query
  */
 function before() {
-   var args = mlutil.asArray.apply(null, arguments);
+   const args = mlutil.asArray.apply(null, arguments);
    if (args.length === 0 || args[0] === null) {
      throw new Error('missing Timestamp');
    } else if (args.length>1) {
@@ -3196,7 +3196,7 @@ util.inherits(BeforeQueryDef, QueryDef);
  * @returns {queryBuilder.Query} a composable query
  */
 function after() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length === 0 || args[0] === null) {
     throw new Error('missing Timestamp');
   } else if (args.length>1) {
@@ -3254,19 +3254,19 @@ function TermOptionsDef(options) {
 }
 /** @ignore */
 function textQuery(variant, args) {
-  var isValue = (variant === 'value');
-
-  var index = null;
-  var text = null;
-  var weight = null;
-  var fragmentScope = null;
-  var termOptions = null;
-  var suggestOptions = null;
-  var constraintName = null;
-  var defaultConstraint = null;
-  var jsontype = null;
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  const isValue = (variant === 'value');
+
+  let index = null;
+  let text = null;
+  let weight = null;
+  let fragmentScope = null;
+  let termOptions = null;
+  let suggestOptions = null;
+  let constraintName = null;
+  let defaultConstraint = null;
+  let jsontype = null;
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (i === 0) {
       index = asIndex(arg);
@@ -3324,7 +3324,7 @@ function textQuery(variant, args) {
       null;
   }
 
-  var textDef = new TextDef(
+  const textDef = new TextDef(
       index, jsontype, text, weight, termOptions, fragmentScope
   );
 
@@ -3348,7 +3348,7 @@ function textQuery(variant, args) {
     }
   }
 
-  var constraint = isValue ?
+  const constraint = isValue ?
       new ValueConstraintDef(constraintName, textDef, suggestOptions) :
       new WordConstraintDef(constraintName,  textDef, suggestOptions);
 
@@ -3361,7 +3361,7 @@ function DefaultConstraintDef(constraintDef) {
     return new DefaultConstraintDef(constraintDef);
   }
 
-  this['default'] = constraintDef;
+  this.default = constraintDef;
 }
 /** @ignore */
 function ValueConstraintDef(constraintName, textDef, suggestOptions) {
@@ -3535,7 +3535,7 @@ function JSONTypeDef(type) {
     return new JSONTypeDef(type);
   }
 
-  var isJSONType = {
+  const isJSONType = {
       'boolean': true,
       'null':    true,
       'number':  true,
@@ -3627,18 +3627,18 @@ function word() {
  * @returns {queryBuilder.BuiltQuery} a built query
  */
 function copyFromQueryBuilder(otherQueryBuilder) {
-  var qb = new QueryBuilder();
+  const qb = new QueryBuilder();
   if (otherQueryBuilder != null) {
-    var clauseKeys = [
+    const clauseKeys = [
       'whereClause', 'calculateClause', 'orderByClause',
       'sliceClause', 'withOptionsClause'
     ];
-    var isString = (typeof otherQueryBuilder === 'string' || otherQueryBuilder instanceof String);
-    var other = isString ?
+    const isString = (typeof otherQueryBuilder === 'string' || otherQueryBuilder instanceof String);
+    const other = isString ?
         JSON.parse(otherQueryBuilder) : otherQueryBuilder;
-    for (var i=0; i < clauseKeys.length; i++){
-      var key = clauseKeys[i];
-      var value = other[key];
+    for (let i=0; i < clauseKeys.length; i++){
+      const key = clauseKeys[i];
+      const value = other[key];
       if (value != null) {
         // structuredClone instead of clone to avoid preserving prototype
         qb[key] = isString ? value : structuredClone(value);
@@ -3670,19 +3670,19 @@ function copyFromQueryBuilder(otherQueryBuilder) {
  */
 function where() {
   /*jshint validthis:true */
-  var self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
+  const self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
 
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   // TODO: if empty, clear the clause
 
-  var parsedQuery = null;
-  var fragmentScope = null;
-  var queries = null;
+  let parsedQuery = null;
+  let fragmentScope = null;
+  let queries = null;
 
-  var i=0;
+  let i=0;
 
-  var arg = (argLen > 0) ? args[0] : null;
+  let arg = (argLen > 0) ? args[0] : null;
   if (arg == null) {
     self.whereClause = {query: {queries: [and()]}};
     self.queryType = 'structured';
@@ -3715,7 +3715,7 @@ function where() {
         queries.push(checkQuery(arg));
       }
     }
-    var whereClause = {};
+    const whereClause = {};
     if (queries !== null) {
       whereClause.query = {queries: queries};
     }
@@ -3756,7 +3756,7 @@ QueryBuilder.prototype.where = where;
  * for the {@link queryBuilder#where} function
  */
 function byExample() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     return {$query: []};
@@ -3787,18 +3787,18 @@ function byExample() {
  */
 function orderBy() {
   /*jshint validthis:true */
-  var self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
+  const self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
 
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   // TODO: if empty, clear the clause
 
-  var sortOrder = [];
+  const sortOrder = [];
 
-  var scoreOption    = null;
-  var scoreDirection = null;
+  let scoreOption    = null;
+  let scoreDirection = null;
 
-  var arg = null;
-  for (var i=0; i < args.length; i++) {
+  let arg = null;
+  for (let i=0; i < args.length; i++) {
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       sortOrder.push(sort(arg));
@@ -3879,24 +3879,24 @@ function score() {
  * for the {@link queryBuilder#orderBy} function
  */
 function sort() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length === 0) {
     throw new Error('missing sorted index');
   }
 
-  var firstIndex = asIndex(args[0]);
+  const firstIndex = asIndex(args[0]);
   // null is a legitimate value of score
-  var isScore    = (firstIndex.score !== void 0);
+  const isScore    = (firstIndex.score !== void 0);
 
-  var sorter = {};
+  const sorter = {};
   if (isScore) {
     sorter.score = firstIndex.score;
   } else {
     addIndex(sorter, firstIndex, false);
   }
 
-  var arg = null;
-  for (var i=1; i < args.length; i++) {
+  let arg = null;
+  for (let i=1; i < args.length; i++) {
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       switch (arg) {
@@ -3944,7 +3944,7 @@ function transform(name, params) {
     throw new Error('transform without name');
   }
 
-  var transformList = [name];
+  const transformList = [name];
   if (params != null) {
     transformList.push(params);
   }
@@ -3995,9 +3995,9 @@ util.inherits(TrueQueryDef, QueryDef);
  */
 function slice() {
   /*jshint validthis:true */
-  var self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
+  const self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
 
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   // TODO: if empty, clear the clause
 
@@ -4021,12 +4021,12 @@ QueryBuilder.prototype.slice = slice;
  */
 function calculate() {
   /*jshint validthis:true */
-  var self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
+  const self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
 
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   // TODO: distinguish facets and values
-  var calculateClause = {
+  const calculateClause = {
       constraint: args
   };
 
@@ -4070,13 +4070,13 @@ QueryBuilder.prototype.calculate = calculate;
  * for the {@link queryBuilder#calculate} function
  */
 function facet() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('facet must at a minimum identify the index');
   }
 
-  var isConstraintIndex = {
+  const isConstraintIndex = {
     collection:               true,
     element:                  true,
     field:                    true,
@@ -4089,7 +4089,7 @@ function facet() {
     'json-property':          true,
     'path-index':             true
   };
-  var isGeoLocationIndex = {
+  const isGeoLocationIndex = {
     'geo-attr-pair':          true,
     'geo-elem':               true,
     'geo-elem-pair':          true,
@@ -4098,19 +4098,19 @@ function facet() {
     'geo-path':               true
   };
 
-  var constraintName = null;
-  var constraintIndex = null;
-  var firstKey = null;
-  var datatype;
-  var collation;
-  var facetOptions;
-  var calculateFunction;
-  var buckets = null;
-  var computedBuckets = null;
-  var heatmap = null;
-
-  var arg = null;
-  for (var i=0; i < argLen; i++) {
+  let constraintName = null;
+  let constraintIndex = null;
+  let firstKey = null;
+  let datatype;
+  let collation;
+  let facetOptions;
+  let calculateFunction;
+  let buckets = null;
+  let computedBuckets = null;
+  let heatmap = null;
+
+  let arg = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     switch(i) {
     case 0:
@@ -4210,8 +4210,8 @@ function facet() {
     }
   }
 
-  var facetWrapper = {name: constraintName};
-  var constraint = {facet: true};
+  const facetWrapper = {name: constraintName};
+  const constraint = {facet: true};
   if (constraintIndex.collection !== undefined) {
     facetWrapper.collection = constraint;
   } else if (calculateFunction !== undefined) {
@@ -4231,10 +4231,10 @@ function facet() {
         constraint.collation = collation;
       }
     }
-    var constraintKeys = Object.keys(constraintIndex);
-    var constraintKeyLen = constraintKeys.length;
-    for (var j=0; j < constraintKeyLen; j++) {
-      var key = constraintKeys[j];
+    const constraintKeys = Object.keys(constraintIndex);
+    const constraintKeyLen = constraintKeys.length;
+    for (let j=0; j < constraintKeyLen; j++) {
+      const key = constraintKeys[j];
       constraint[key] = constraintIndex[key];
     }
     if (buckets !== null) {
@@ -4274,14 +4274,14 @@ function facet() {
  * module for the {@link queryBuilder#facet} function.
  */
 function calculateFunction() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   if (args.length < 1) {
     throw new Error('calculate function without module name');
   }
 
-  var moduleName = args[0];
+  const moduleName = args[0];
 
-  var rootname = mlutil.rootname(moduleName);
+  const rootname = mlutil.rootname(moduleName);
   if (rootname === null) {
     throw new Error('library must have an extension of .xqy');
   }
@@ -4377,7 +4377,7 @@ util.inherits(FalseQueryDef, QueryDef);
  * @returns {queryBuilder.BucketParam} specification for a {@link queryBuilder#facet} calculation
  */
 function bucket() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('must specify name, comparison, and bound for bucket');
@@ -4442,7 +4442,7 @@ function BucketDef(name, lower, upper) {
   this.name  = name;
   this.label = name;
 
-  var lowerType = -1;
+  let lowerType = -1;
   if (lower == null) {
     lowerType = 0;
   } else if (typeof lower === 'number' || lower instanceof Number) {
@@ -4453,7 +4453,7 @@ function BucketDef(name, lower, upper) {
     throw new Error('invalid lower bound for bucket: '+mlutil.identify(lower, true));
   }
 
-  var upperType = -1;
+  let upperType = -1;
   if (upper == null) {
     upperType = 0;
   } else if (typeof upper === 'number' || upper instanceof Number) {
@@ -4491,7 +4491,7 @@ function ComputedBucketDef(name, lower, upper) {
   this.name  = name;
   this.label = name;
 
-  var lowerType = -1;
+  let lowerType = -1;
   if (lower == null) {
     lowerType = 0;
   } else if (lower instanceof AnchorDef) {
@@ -4500,7 +4500,7 @@ function ComputedBucketDef(name, lower, upper) {
     throw new Error('invalid lower bound for computed bucket: '+mlutil.identify(lower, true));
   }
 
-  var upperType = -1;
+  let upperType = -1;
   if (upper == null) {
     upperType = 0;
   } else if (upper instanceof AnchorDef) {
@@ -4561,7 +4561,7 @@ function ComputedBucketDef(name, lower, upper) {
  * as part of a facet calculation
  */
 function anchor() {
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
   switch(args.length) {
   case 0:
     throw new Error('no milestone or lower bound for anchor');
@@ -4591,7 +4591,7 @@ function AnchorDef(milestone, first, comparison, second) {
     throw new Error('invalid milestone for anchor: '+mlutil.identify(milestone, true));
   }
 
-  var comparisonType = -1;
+  let comparisonType = -1;
   if (comparison == null) {
     comparisonType = 0;
   } else if (comparison === '<') {
@@ -4673,10 +4673,10 @@ function defaultConstraintName(index) {
  * the {@link queryBuilder#where} function
  */
 function parsedFrom() {
-  var qtext = null;
-  var bindings = null;
-  var constraints = null;
-  var term = null;
+  let qtext = null;
+  let bindings = null;
+  let constraints = null;
+  let term = null;
 
   switch(arguments.length) {
   case 0:
@@ -4766,20 +4766,20 @@ function parseBindings() {
 }
 /** @ignore */
 function makeBindings(variant, args) {
-  var isParse = (variant === 'parse');
-  var desc = isParse ? 'parsing query text' : 'defining suggestion sources';
+  const isParse = (variant === 'parse');
+  const desc = isParse ? 'parsing query text' : 'defining suggestion sources';
 
-  var argLen = args.length;
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('no bindings for '+desc);
   }
 
-  var constraints = null;
-  var defaultConstraints = null;
-  var suggestOptions = null;
-  var empty = null;
-  var arg = null;
-  for (var i=0; i < argLen; i++) {
+  let constraints = null;
+  let defaultConstraints = null;
+  let suggestOptions = null;
+  let empty = null;
+  let arg = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     if (arg.name !== void 0) {
       if (isParse && (arg['suggest-option'] !== void 0)) {
@@ -4793,7 +4793,7 @@ function makeBindings(variant, args) {
       continue;
     }
     if (defaultConstraints == null) {
-      defaultConstraints = arg['default'];
+      defaultConstraints = arg.default;
       if (defaultConstraints !== void 0) {
         suggestOptions = arg['suggest-option'];
         if (isParse && (suggestOptions !== void 0)) {
@@ -4811,7 +4811,7 @@ function makeBindings(variant, args) {
     throw new Error('unknown argument for parse query binding: '+mlutil.identify(arg, true));
   }
 
-  var termDef = (
+  const termDef = (
       (defaultConstraints == null) &&
       (empty == null) &&
       (suggestOptions == null)
@@ -4844,7 +4844,7 @@ function TermBindingDef(defaultConstraints, empty, suggestOptions) {
   }
 
   if (defaultConstraints != null) {
-      this['default'] = defaultConstraints;
+      this.default = defaultConstraints;
   }
   if (empty != null) {
     this.empty = empty;
@@ -4958,7 +4958,7 @@ function EmptyApplyDef(binding) {
     return new EmptyApplyDef(binding);
   }
 
-  var valid = {'all-results': true, 'no-results': true};
+  const valid = {'all-results': true, 'no-results': true};
 
   if ((typeof binding === 'string' || binding instanceof String) && valid[binding] === true) {
     this.apply = binding;
@@ -4993,18 +4993,18 @@ function EmptyApplyDef(binding) {
  * module for the {@link queryBuilder#parseBindings} function.
  */
 function parseFunction() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 2) {
     throw new Error('query parse function without module name or binding');
   }
 
-  var moduleName = args[0];
+  const moduleName = args[0];
 
-  var constraintName = null;
-  var termOptions = null;
-  var arg = null;
-  for (var i=1; i < args.length; i++) {
+  let constraintName = null;
+  let termOptions = null;
+  let arg = null;
+  for (let i=1; i < args.length; i++) {
     arg = args[i];
     if (termOptions === null && arg instanceof TermOptionsDef) {
       termOptions = arg['term-option'];
@@ -5068,7 +5068,7 @@ function CustomParserDef(moduleName) {
     return new CustomParserDef(moduleName);
   }
 
-  var rootname = mlutil.rootname(moduleName);
+  const rootname = mlutil.rootname(moduleName);
   if (rootname === null) {
     throw new Error('library must have an extension of .xqy');
   }
@@ -5100,19 +5100,19 @@ function CustomParserDef(moduleName) {
  * for the {@link queryBuilder#slice} function
  */
 function extract() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('must specify paths to extract');
   }
 
-  var extractdef = {};
+  const extractdef = {};
 
-  var arg = args[0];
+  const arg = args[0];
   if (typeof arg === 'string' || arg instanceof String) {
     extractdef['extract-path'] = args;
   } else {
-    var paths = arg.paths;
+    const paths = arg.paths;
     if (typeof paths === 'string' || paths instanceof String) {
       extractdef['extract-path'] = [paths];
     } else if (Array.isArray(paths)) {
@@ -5121,12 +5121,12 @@ function extract() {
       throw new Error('first argument does not have key for paths to extract');
     }
 
-    var namespaces = arg.namespaces;
+    const namespaces = arg.namespaces;
     if (namespaces !== void 0) {
       extractdef.namespaces = namespaces;
     }
 
-    var selected = arg.selected;
+    const selected = arg.selected;
     if (selected !== void 0) {
       extractdef.selected = selected;
     }
@@ -5158,10 +5158,10 @@ function extract() {
  * for the {@link queryBuilder#slice} function
  */
 function snippet() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
-  var builtins = {
+  const builtins = {
       empty:              'empty-snippet',
       'empty-snippet':    'empty-snippet',
       metadata:           'metadata-snippet',
@@ -5169,13 +5169,13 @@ function snippet() {
       snippet:            'snippet'
   };
 
-  var snippeter = {
+  const snippeter = {
       apply: 'snippet'
   };
 
-  var arg = null;
-  var builtin = null;
-  for (var i=0; i < argLen; i++) {
+  let arg = null;
+  let builtin = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       builtin = builtins[arg];
@@ -5183,7 +5183,7 @@ function snippet() {
         snippeter.apply = builtin;
         continue;
       } else {
-        var rootname = mlutil.rootname(arg);
+        const rootname = mlutil.rootname(arg);
         snippeter.ns    = 'http://marklogic.com/snippet/custom/'+rootname;
         snippeter.at    = '/ext/marklogic/snippet/custom/'+arg;
         snippeter.apply = 'snippet';
@@ -5228,10 +5228,10 @@ function snippet() {
  */
 function withOptions() {
   /*jshint validthis:true */
-  var self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
+  const self = (this instanceof QueryBuilder) ? this : new QueryBuilder();
 
   // TODO: share with documents.js
-  var optionKeyMapping = {
+  const optionKeyMapping = {
     search:'search-option',     weight:'quality-weight',
     forestNames:'forest',       similarDocs:'return-similar',
     metrics:'return-metrics',   queryPlan:'return-plan',
@@ -5239,14 +5239,14 @@ function withOptions() {
     categories:true,            txid:true
   };
 
-  var withOptionsClause = {};
+  const withOptionsClause = {};
   if (0 < arguments.length) {
-    var arg = arguments[0];
-    var argKeys = Object.keys(arg);
-    for (var i=0; i < argKeys.length; i++) {
-      var key = argKeys[i];
+    const arg = arguments[0];
+    const argKeys = Object.keys(arg);
+    for (let i=0; i < argKeys.length; i++) {
+      const key = argKeys[i];
       if (optionKeyMapping[key] !== void 0) {
-        var value = arg[key];
+        const value = arg[key];
         if (value !== void 0) {
           withOptionsClause[key] = value;
         } else {
@@ -5268,17 +5268,17 @@ function makeSearchBody(builtQuery) {
     throw new Error('no query for documents');
   }
 
-  var categories  = null;
-  var optionsName = null;
-  var pageStart   = null;
-  var pageLength  = null;
-  var txid        = null;
-  var transform   = null;
-  var view        = null;
+  let categories  = null;
+  let optionsName = null;
+  let pageStart   = null;
+  let pageLength  = null;
+  let txid        = null;
+  let transform   = null;
+  let view        = null;
 
-  var i=0;
+  let i=0;
 
-  var searchBody = {};
+  const searchBody = {};
   if (builtQuery.search !== void 0) {
     searchBody.search = builtQuery.search;
 
@@ -5307,10 +5307,10 @@ function makeSearchBody(builtQuery) {
     categories = (builtQuery.categories !== void 0) ?
         builtQuery.categories : ['content'];
   } else {
-    var search = {};
+    const search = {};
     searchBody.search = search;
 
-    var searchOptions = search.options;
+    let searchOptions = search.options;
     if (searchOptions == null) {
       searchOptions = {};
       search.options = searchOptions;
@@ -5318,11 +5318,11 @@ function makeSearchBody(builtQuery) {
 
     // TODO: validate clauses
 
-    var whereClause = builtQuery.whereClause;
+    const whereClause = builtQuery.whereClause;
     if (builtQuery.queryType === 'qbe') {
       search.$query = whereClause.$query;
-      var format    = whereClause.$format;
-      var validate  = whereClause.$validate;
+      const format    = whereClause.$format;
+      const validate  = whereClause.$validate;
       if (format != null) {
         search.$format = format;
       }
@@ -5332,9 +5332,9 @@ function makeSearchBody(builtQuery) {
     } else if (builtQuery.queryType === 'cts') {
       search.ctsast = bldrbase.exportArg(whereClause);
     } else if (whereClause != null) {
-      var query         = whereClause.query;
-      var parsedQuery   = whereClause.parsedQuery;
-      var fragmentScope = whereClause['fragment-scope'];
+      const query         = whereClause.query;
+      const parsedQuery   = whereClause.parsedQuery;
+      const fragmentScope = whereClause['fragment-scope'];
 
       if (query != null) {
         search.query = query;
@@ -5347,7 +5347,7 @@ function makeSearchBody(builtQuery) {
       }
     }
 
-    var calculateClause = builtQuery.calculateClause;
+    const calculateClause = builtQuery.calculateClause;
     if (calculateClause != null) {
       view = 'results';
       searchOptions['return-facets']     = true;
@@ -5355,30 +5355,30 @@ function makeSearchBody(builtQuery) {
       searchOptions['return-metrics']    = false;
       searchOptions['return-qtext']      = false;
       searchOptions['transform-results'] = {apply: 'empty-snippet'};
-      var searchConstraintList = searchOptions.constraint;
+      const searchConstraintList = searchOptions.constraint;
       if (searchConstraintList == null) {
         searchOptions.constraint = calculateClause.constraint;
       } else {
         // TODO: convert into a generic deep merge utility
-        var constraintLookup = {};
-        for (var li=0; li < searchConstraintList.length; li++) {
-          var lookupConstraint = searchConstraintList[li];
+        const constraintLookup = {};
+        for (let li=0; li < searchConstraintList.length; li++) {
+          const lookupConstraint = searchConstraintList[li];
           constraintLookup[lookupConstraint.name] = lookupConstraint;
         }
 
-        var calculateConstraints = calculateClause.constraint;
-        for (var mi=0; mi < calculateConstraints.length; mi++) {
-          var calculateConstraint = calculateConstraints[mi];
-          var searchConstraint = constraintLookup[calculateConstraint.name];
+        const calculateConstraints = calculateClause.constraint;
+        for (let mi=0; mi < calculateConstraints.length; mi++) {
+          const calculateConstraint = calculateConstraints[mi];
+          const searchConstraint = constraintLookup[calculateConstraint.name];
           if (searchConstraint == null) {
             searchConstraintList.push(calculateConstraint);
           } else {
-            var constraintChildKeys =
+            const constraintChildKeys =
               Object.keys(calculateConstraint).filter(notNameFilter);
-            for (var ki=0; ki < constraintChildKeys.length; ki++) {
-              var constraintChildKey = constraintChildKeys[ki];
-              var searchChild = searchConstraint[constraintChildKey];
-              var searchType = (searchChild === null) ?
+            for (let ki=0; ki < constraintChildKeys.length; ki++) {
+              const constraintChildKey = constraintChildKeys[ki];
+              const searchChild = searchConstraint[constraintChildKey];
+              const searchType = (searchChild === null) ?
                   'undefined' : typeof searchChild;
               switch(searchType) {
               case 'boolean':
@@ -5399,7 +5399,7 @@ function makeSearchBody(builtQuery) {
       }
     }
 
-    var searchFlags = searchOptions['search-option'];
+    let searchFlags = searchOptions['search-option'];
     if (searchFlags == null) {
       searchFlags = ['unfiltered'];
       searchOptions['search-option'] = searchFlags;
@@ -5407,11 +5407,11 @@ function makeSearchBody(builtQuery) {
       searchFlags.push('unfiltered');
     }
 
-    var orderByClause = builtQuery.orderByClause;
+    const orderByClause = builtQuery.orderByClause;
     if (orderByClause != null) {
       searchOptions['sort-order'] = orderByClause['sort-order'];
 
-      var scoreOption = orderByClause.scoreOption;
+      const scoreOption = orderByClause.scoreOption;
       if (scoreOption !== null && scoreOption !== void 0) {
         for (i=0; i < searchFlags.length; i++) {
           if (searchFlags[i].indexOf('score-') !== -1) {
@@ -5424,25 +5424,25 @@ function makeSearchBody(builtQuery) {
       }
     }
 
-    var sliceClause = builtQuery.sliceClause;
+    const sliceClause = builtQuery.sliceClause;
     if (sliceClause != null) {
-      var sliceStart = sliceClause['page-start'];
+      const sliceStart = sliceClause['page-start'];
       if (sliceStart != null) {
         pageStart = sliceStart;
       }
-      var sliceLength = sliceClause['page-length'];
+      const sliceLength = sliceClause['page-length'];
       if (sliceLength != null) {
         pageLength = sliceLength;
       }
 
-      var transformResults = sliceClause['transform-results'];
+      const transformResults = sliceClause['transform-results'];
       if (transformResults != null) {
         searchOptions['transform-results'] = transformResults;
         searchOptions['return-results']    = true;
         view = 'results';
       }
 
-      var extractResults = sliceClause['extract-document-data'];
+      const extractResults = sliceClause['extract-document-data'];
       if (extractResults != null) {
         searchOptions['extract-document-data'] = extractResults;
       }
@@ -5452,27 +5452,27 @@ function makeSearchBody(builtQuery) {
 
     categories = (pageLength > 0) ? ['content'] : null;
 
-    var withOptionsClause = builtQuery.withOptionsClause;
+    const withOptionsClause = builtQuery.withOptionsClause;
     if (withOptionsClause != null) {
       // TODO: share with queryBuilder.js
-      var optionKeyMapping = {
+      const optionKeyMapping = {
           search:'search-option',     weight:'quality-weight',
           forestNames:'forest',       similarDocs:'return-similar',
           metrics:'return-metrics',   queryPlan:'return-plan',
           debug:'debug',              concurrencyLevel:'concurrency-level',
           categories:true,            txid:true
         };
-      var optionKeyInResponse = {
+      const optionKeyInResponse = {
           similarDocs:true, metrics:true,
           queryPlan:true,   debug:true
         };
 
-      var optionsKeys = Object.keys(withOptionsClause);
+      const optionsKeys = Object.keys(withOptionsClause);
       for (i=0; i < optionsKeys.length; i++) {
-        var key     = optionsKeys[i];
-        var mapping = optionKeyMapping[key];
+        const key     = optionsKeys[i];
+        const mapping = optionKeyMapping[key];
         if (mapping != null) {
-          var value = withOptionsClause[key];
+          const value = withOptionsClause[key];
           if (value != null) {
             if (mapping === true) {
               switch(key) {
@@ -5509,15 +5509,15 @@ function makeSearchBody(builtQuery) {
   };
 }
 function makeParsedQuery(searchBody, parsedQuery) {
-  var search   = searchBody.search;
+  const search   = searchBody.search;
   search.qtext = parsedQuery.qtext;
 
-  var constraintBindings = parsedQuery.constraint;
-  var hasConstraints     = (constraintBindings != null);
-  var termBinding        = parsedQuery.term;
-  var hasTerm            = (termBinding != null);
+  const constraintBindings = parsedQuery.constraint;
+  const hasConstraints     = (constraintBindings != null);
+  const termBinding        = parsedQuery.term;
+  const hasTerm            = (termBinding != null);
   if (hasConstraints || hasTerm) {
-    var searchOptions = search.options;
+    let searchOptions = search.options;
     if (searchOptions == null) {
       searchOptions = {};
       search.options = searchOptions;
diff --git a/lib/requester.js b/lib/requester.js
index 7d4d3ba8..63bd1479 100644
--- a/lib/requester.js
+++ b/lib/requester.js
@@ -2,19 +2,19 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var createAuthInitializer = require('./www-authenticate-patched/www-authenticate');
-var Kerberos              = require('./optional.js')
+const createAuthInitializer = require('./www-authenticate-patched/www-authenticate');
+const Kerberos              = require('./optional.js')
                             .libraryProperty('kerberos', 'Kerberos');
-var Multipart             = require('multipart-stream');
-var through2              = require('through2');
-var mlutil                = require('./mlutil.js');
-var responder             = require('./responder.js');
-var kerberos = null;
+const Multipart             = require('multipart-stream');
+const through2              = require('through2');
+const mlutil                = require('./mlutil.js');
+const responder             = require('./responder.js');
+let kerberos = null;
 const https = require('https');
 const formData = require('form-data');
 
 function createAuthenticator(client, user, password, challenge) {
-  var authenticator = createAuthInitializer.call(null, user, password)(challenge);
+  const authenticator = createAuthInitializer.call(null, user, password)(challenge);
   if (!client.authenticator) {
     client.authenticator = {};
   }
@@ -23,7 +23,7 @@ function createAuthenticator(client, user, password, challenge) {
 }
 
 function createAuthenticatorKerberos(client, credentials) {
-  var authenticatorKerberos = {
+  const authenticatorKerberos = {
     'credentials': credentials
   };
   client.authenticatorKerberos = authenticatorKerberos;
@@ -81,11 +81,11 @@ function getAccessToken(operation){
 }
 
 function startRequest(operation) {
-  var options = operation.options;
-  var operationErrorListener = responder.operationErrorListener;
+  const options = operation.options;
+  const operationErrorListener = responder.operationErrorListener;
   operation.errorListener = mlutil.callbackOn(operation, operationErrorListener);
 
-  var headers = options.headers;
+  let headers = options.headers;
   if (headers == null) {
     headers = {};
     options.headers = headers;
@@ -96,8 +96,8 @@ function startRequest(operation) {
   if(options.enableGzippedResponses) {
     headers['Accept-Encoding'] = 'gzip';
   }
-  var started                = null;
-  var operationResultPromise = null;
+  let started                = null;
+  let operationResultPromise = null;
 
   switch(operation.requestType) {
   case 'empty':
@@ -127,12 +127,12 @@ function startRequest(operation) {
   }
 
   const authType = options.authType.toUpperCase();
-  var needsAuthenticator = (
+  let needsAuthenticator = (
       authType === 'DIGEST' ||
       authType === 'KERBEROS'
   );
   if (needsAuthenticator) {
-    var authenticator = null;
+    let authenticator = null;
     switch(authType) {
     case 'DIGEST':
       authenticator = getAuthenticator(operation.client, options.user);
@@ -173,23 +173,23 @@ function startRequest(operation) {
   }
 
   if (started === null) {
-    var ResponseSelector = responder.ResponseSelector;
+    const ResponseSelector = responder.ResponseSelector;
     started = new ResponseSelector(operation);
   }
 
   return started;
 }
 function challengeRequest(operation) {
-  var isRead        = (operation.inputSender === null);
-  var options       = operation.options;
-  var challengeOpts = isRead ? options : {
+  const isRead        = (operation.inputSender === null);
+  const options       = operation.options;
+  const challengeOpts = isRead ? options : {
     method:     'HEAD',
     path:       '/v1/ping'
   };
   if (!isRead) {
     Object.keys(options).forEach(function optionKeyCopier(key) {
       if (challengeOpts[key] === void 0) {
-        var value = options[key];
+        const value = options[key];
         if (value != null) {
           challengeOpts[key] = value;
         }
@@ -199,10 +199,10 @@ function challengeRequest(operation) {
 
   operation.logger.debug('challenge request for %s', challengeOpts.path);
   var request1 = operation.client.request(challengeOpts, function challengeResponder(response1) {
-    var statusCode1   = response1.statusCode;
-    var successStatus = (statusCode1 < 400);
-    var challenge     = response1.headers['www-authenticate'];
-    var hasChallenge  = (challenge != null);
+    const statusCode1   = response1.statusCode;
+    const successStatus = (statusCode1 < 400);
+    const challenge     = response1.headers['www-authenticate'];
+    const hasChallenge  = (challenge != null);
 
     operation.logger.debug('response with status %d and %s challenge for %s',
         statusCode1, hasChallenge, challengeOpts.path);
@@ -218,7 +218,7 @@ function challengeRequest(operation) {
       authenticatedRequest(operation);
     // should never happen
     } else if (successStatus && isRead) {
-      var responseDispatcher = responder.responseDispatcher;
+      const responseDispatcher = responder.responseDispatcher;
       responseDispatcher.call(operation, response1);
     } else if (isRetry(response1)) {
       retryRequest(operation, response1, challengeRequest);
@@ -232,7 +232,7 @@ function challengeRequest(operation) {
 }
 function credentialsRequest(operation) {
   kerberos = new Kerberos();
-  var uri = 'HTTP@'+operation.options.host;
+  const uri = 'HTTP@'+operation.options.host;
   kerberos.authGSSClientInit(uri, 0, function(err, ctx) {
     if (err) {
       operation.errorListener('kerberos initialization failed at '+uri);
@@ -257,12 +257,12 @@ function credentialsRequest(operation) {
   });
 }
 function authenticatedRequest(operation) {
-  var isRead = (operation.inputSender === null);
-  var options = operation.options;
+  const isRead = (operation.inputSender === null);
+  const options = operation.options;
   operation.logger.debug('authenticated request for %s', options.path);
-  var authenticator = operation.authenticator;
-  var responseDispatcher = operation.isReplayable ? retryDispatcher : responder.responseDispatcher;
-  var request = operation.client.request(
+  const authenticator = operation.authenticator;
+  const responseDispatcher = operation.isReplayable ? retryDispatcher : responder.responseDispatcher;
+  const request = operation.client.request(
       options, mlutil.callbackOn(operation, responseDispatcher)
       );
   const authType = options.authType.toUpperCase();
@@ -364,9 +364,9 @@ function retryRequest(operation, response, requestSender) {
 
 function singleRequester(request) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var requestSource = mlutil.marshal(operation.requestBody, operation);
+  const requestSource = mlutil.marshal(operation.requestBody, operation);
   if (requestSource == null) {
     request.end();
   } else if (typeof requestSource === 'string' || requestSource instanceof String) {
@@ -382,13 +382,13 @@ function singleRequester(request) {
 }
 function multipartRequester(request) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var operationBoundary = operation.multipartBoundary;
-  var multipartStream = new Multipart((operationBoundary == null) ?
+  const operationBoundary = operation.multipartBoundary;
+  const multipartStream = new Multipart((operationBoundary == null) ?
         mlutil.multipartBoundary : operationBoundary);
 
-  var requestPartsProvider = operation.requestPartsProvider;
+  const requestPartsProvider = operation.requestPartsProvider;
   if(operation.bindingParam) {
     const form = new formData();
     const bindingParam = operation.bindingParam;
@@ -443,14 +443,14 @@ function multipartRequester(request) {
   } else if (typeof requestPartsProvider === 'function') {
     requestPartsProvider.call(operation, multipartStream);
   } else {
-    var parts = operation.requestPartList;
+    const parts = operation.requestPartList;
     if (Array.isArray(parts)) {
-      var partsLen = parts.length;
+      const partsLen = parts.length;
       operation.logger.debug('writing %s parts', partsLen);
-      for (var i=0; i < partsLen; i++) {
-        var part = parts[i];
-        var headers = part.headers;
-        var content = part.content;
+      for (let i=0; i < partsLen; i++) {
+        const part = parts[i];
+        const headers = part.headers;
+        const content = part.content;
         if ((headers != null) &&
             (content != null)) {
           operation.logger.debug('starting part %s', i);
@@ -471,9 +471,9 @@ function multipartRequester(request) {
 }
 function chunkedRequester(request) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var requestWriter = operation.requestWriter;
+  const requestWriter = operation.requestWriter;
   if (requestWriter === null || requestWriter === undefined) {
     operation.errorListener('no request writer for streaming request');
     request.end();
@@ -483,10 +483,10 @@ function chunkedRequester(request) {
 }
 function chunkedMultipartRequester(request) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var requestWriter = operation.requestWriter;
-  var requestDocument = operation.requestDocument;
+  const requestWriter = operation.requestWriter;
+  const requestDocument = operation.requestDocument;
   if (requestWriter == null) {
     operation.errorListener('no request writer for streaming request');
     request.end();
@@ -494,17 +494,17 @@ function chunkedMultipartRequester(request) {
     operation.errorListener('no request document for streaming request');
     request.end();
   } else {
-    var operationBoundary = operation.multipartBoundary;
+    const operationBoundary = operation.multipartBoundary;
 
-    var multipartStream = new Multipart((operationBoundary == null) ?
+    const multipartStream = new Multipart((operationBoundary == null) ?
         mlutil.multipartBoundary : operationBoundary);
 
-    var partLast = requestDocument.length - 1;
-    for (var i=0; i <= partLast; i++) {
-      var part = requestDocument[i];
-      var headers = part.headers;
+    const partLast = requestDocument.length - 1;
+    for (let i=0; i <= partLast; i++) {
+      const part = requestDocument[i];
+      const headers = part.headers;
       if (i < partLast) {
-        var content = part.content;
+        const content = part.content;
         if ((headers != null) &&
             (content != null)) {
           multipartStream.addPart({
diff --git a/lib/resources-config.js b/lib/resources-config.js
index 6846a5ca..97762dcf 100644
--- a/lib/resources-config.js
+++ b/lib/resources-config.js
@@ -2,16 +2,16 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /** @ignore */
 function nameErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var name = operation.name;
+  const name = operation.name;
   return (name == null) ? message :
     (message+' (on '+name+' resource service)');
 }
@@ -26,7 +26,7 @@ function nameErrorTransform(message) {
 /** @ignore */
 function emptyOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   return {
     name: operation.name
@@ -59,11 +59,11 @@ Resources.prototype.read = function readResourceConfig(name) {
     throw new Error('must specify name when reading the resource service source');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.path = '/v1/config/resources/'+encodeURIComponent(name);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read resource service', this.client, requestOptions, 'empty', 'single'
       );
   operation.name            = name;
@@ -82,21 +82,21 @@ Resources.prototype.read = function readResourceConfig(name) {
  * @param {object|string} source - the source for the resource service
  */
 Resources.prototype.write = function writeResourceConfig() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen === 0) {
     throw new Error('no arguments for writing an extension library');
   }
 
-  var name        = null;
-  var title       = null;
-  var description = null;
-  var provider    = null;
-  var version     = null;
-  var format      = null;
-  var source      = null;
+  let name        = null;
+  let title       = null;
+  let description = null;
+  let provider    = null;
+  let version     = null;
+  let format      = null;
+  let source      = null;
 
-  var params = null;
+  let params = null;
   if (argLen === 1) {
     params = args[0];
     name        = params.name;
@@ -117,7 +117,7 @@ Resources.prototype.write = function writeResourceConfig() {
     throw new Error('must specify name, format, and source when writing a resource service');
   }
 
-  var contentType = null;
+  let contentType = null;
   switch(format) {
   case 'javascript':
     contentType = 'application/javascript';
@@ -129,9 +129,9 @@ Resources.prototype.write = function writeResourceConfig() {
     throw new Error('unsupported resource service format '+format);
   }
 
-  var endpoint = '/v1/config/resources/'+encodeURIComponent(name);
+  let endpoint = '/v1/config/resources/'+encodeURIComponent(name);
 
-  var sep = '?';
+  let sep = '?';
   if (title != null) {
     endpoint += sep+'title='+encodeURIComponent(title);
     if (sep === '?') {sep = '&';}
@@ -149,14 +149,14 @@ Resources.prototype.write = function writeResourceConfig() {
     if (sep === '?') {sep = '&';}
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'PUT';
   requestOptions.headers = {
       'Content-Type': contentType
   };
   requestOptions.path = endpoint;
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write resource service', this.client, requestOptions, 'single', 'empty'
       );
   operation.name            = name;
@@ -178,11 +178,11 @@ Resources.prototype.remove = function removeResourceConfig(name) {
     throw new Error('must specify name when deleting the resource service source');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'DELETE';
   requestOptions.path = '/v1/config/resources/'+encodeURIComponent(name);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'remove resource service', this.client, requestOptions, 'empty', 'empty'
       );
   operation.name            = name;
@@ -201,14 +201,14 @@ Resources.prototype.remove = function removeResourceConfig(name) {
  * on the server
  */
 Resources.prototype.list = function listResourceConfig() {
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.headers = {
       'Accept': 'application/json'
   };
   requestOptions.path = '/v1/config/resources';
 
-  var operation = new Operation(
+  const operation = new Operation(
       'list resource services', this.client, requestOptions, 'empty', 'single'
       );
 
diff --git a/lib/resources-exec.js b/lib/resources-exec.js
index d9b9db70..c3103da0 100644
--- a/lib/resources-exec.js
+++ b/lib/resources-exec.js
@@ -2,9 +2,9 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /**
  * Provides functions to execute resource services on the REST server
@@ -20,7 +20,7 @@ function checkArgs() {
     throw new Error('no argument for executing resource service');
   }
 
-  var args = arguments[0];
+  const args = arguments[0];
   if (args.name === void 0) {
     throw new Error('no name for executing resource service');
   }
@@ -29,18 +29,18 @@ function checkArgs() {
 }
 /** @ignore */
 function makeRequestOptions(client, args) {
-  var path = '/v1/resources/'+args.name;
-
-  var sep ='?';
-
-  var params = args.params;
-  var keys = (params === void 0) ? null : Object.keys(params);
-  var keyLen = (keys === null) ? 0 : keys.length;
-  var key = null;
-  var prefix = null;
-  var i=0;
-  var value = null;
-  var j=0;
+  let path = '/v1/resources/'+args.name;
+
+  let sep ='?';
+
+  const params = args.params;
+  const keys = (params === void 0) ? null : Object.keys(params);
+  const keyLen = (keys === null) ? 0 : keys.length;
+  let key = null;
+  let prefix = null;
+  let i=0;
+  let value = null;
+  let j=0;
   for (; i < keyLen; i++) {
     key = keys?keys[i]:null;
     if(params){
@@ -63,7 +63,7 @@ function makeRequestOptions(client, args) {
     }
   }
 
-  var txid = mlutil.convertTransaction(args.txid);
+  const txid = mlutil.convertTransaction(args.txid);
   if (txid !== undefined && txid != null) {
     path += sep+'txid='+mlutil.getTxidParam(txid);
     if (sep === '?') {
@@ -109,9 +109,9 @@ Resources.prototype.get = function getResourceExec() {
       );
 };
 Resources.prototype.getReadStream = function getResourceExecStream() {
-  var args = checkArgs.apply(null, arguments);
+  const args = checkArgs.apply(null, arguments);
 
-  var contentType = args.contentType;
+  const contentType = args.contentType;
   if (contentType == null) {
     throw new Error('no content type for reading stream from resource service');
   }
@@ -120,13 +120,13 @@ Resources.prototype.getReadStream = function getResourceExecStream() {
 };
 /** @ignore */
 function readResourceExec(self, responseType, contentType, args) {
-  var requestOptions = makeRequestOptions(self.client, args);
+  const requestOptions = makeRequestOptions(self.client, args);
   requestOptions.method = 'GET';
   requestOptions.headers = {
       'Accept': contentType
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'execute remove service', self.client, requestOptions, 'empty', responseType
       );
   operation.name = args.name;
@@ -179,19 +179,19 @@ Resources.prototype.putWriteStream  = function putResourceExecStream() {
 };
 /** @ignore */
 function writeResourceStream(self, method, responseType, args) {
-  var contentType = args.contentType;
+  const contentType = args.contentType;
   if (contentType == null) {
     throw new Error('no content type for writing stream to resource service');
   }
 
-  var requestOptions = makeRequestOptions(self.client, args);
+  const requestOptions = makeRequestOptions(self.client, args);
   requestOptions.headers = {
       'Content-Type': contentType,
       'Accept': 'application/json'
   };
   requestOptions.method = method;
 
-  var operation = new Operation(
+  const operation = new Operation(
       'execute '+method+' service stream', self.client, requestOptions,
       'chunked', responseType
       );
@@ -203,16 +203,16 @@ function writeResourceStream(self, method, responseType, args) {
 }
 /** @ignore */
 function writeResources(self, method, responseType, args) {
-  var documents = args.documents;
+  let documents = args.documents;
 
-  var isEmpty = (documents == null);
+  const isEmpty = (documents == null);
   if (!isEmpty && !Array.isArray(documents)) {
     documents = [documents];
   }
 
-  var multipartBoundary = mlutil.multipartBoundary;
+  const multipartBoundary = mlutil.multipartBoundary;
 
-  var requestOptions = makeRequestOptions(self.client, args);
+  const requestOptions = makeRequestOptions(self.client, args);
   requestOptions.method = method;
   requestOptions.headers = (!isEmpty) ?
     {
@@ -223,7 +223,7 @@ function writeResources(self, method, responseType, args) {
         'Accept': 'application/json'
     };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'execute '+method+' service', self.client, requestOptions,
       (isEmpty ? 'empty' : 'multipart'), responseType
       );
@@ -234,7 +234,7 @@ function writeResources(self, method, responseType, args) {
 
   operation.requestPartList = [];
   if (typeof documents !== 'undefined' && documents !== null) {
-    for (var i=0; i < documents.length; i++) {
+    for (let i=0; i < documents.length; i++) {
       addPart(operation, documents[i]);
     }
   }
@@ -245,17 +245,17 @@ function writeResources(self, method, responseType, args) {
 }
 /** @ignore */
 function addPart(operation, document) {
-  var headers = {};
-  var part    = {
+  const headers = {};
+  const part    = {
       headers: headers
       };
 
-  var content       = document.content;
-  var hasContent    = (content != null);
-  var contentType   = hasContent ? document.contentType : null;
+  const content       = document.content;
+  const hasContent    = (content != null);
+  const contentType   = hasContent ? document.contentType : null;
 
   if (hasContent && (contentType != null)) {
-    var marshaledData = mlutil.marshal(content, operation);
+    const marshaledData = mlutil.marshal(content, operation);
 /* TODO: allow encoding in multipart parse
     headers['Content-Type'] = contentType +
       ((typeof marshaledData === 'string' || marshaledData instanceof String) ? '; charset=utf-8' : '');
@@ -291,15 +291,15 @@ function addPart(operation, document) {
  * multi-statement transaction
  */
 Resources.prototype.remove = function removeResourceExec() {
-  var args = checkArgs.apply(null, arguments);
+  const args = checkArgs.apply(null, arguments);
 
-  var requestOptions = makeRequestOptions(this.client, args);
+  const requestOptions = makeRequestOptions(this.client, args);
   requestOptions.headers = {
       'Accept': 'application/json'
   };
   requestOptions.method  = 'DELETE';
 
-  var operation = new Operation(
+  const operation = new Operation(
       'execute remove service', this.client, requestOptions, 'empty', 'single'
       );
   operation.name = args.name;
diff --git a/lib/responder.js b/lib/responder.js
index b5f6793f..412ca64d 100644
--- a/lib/responder.js
+++ b/lib/responder.js
@@ -2,11 +2,11 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var concatStream = require('concat-stream');
-var jsonParser   = require('json-text-sequence').Parser;
-var Dicer        = require('@fastify/busboy/deps/dicer/lib/Dicer');
-var through2     = require('through2');
-var mlutil       = require('./mlutil.js');
+const concatStream = require('concat-stream');
+const jsonParser   = require('json-text-sequence').Parser;
+const Dicer        = require('@fastify/busboy/deps/dicer/lib/Dicer');
+const through2     = require('through2');
+const mlutil       = require('./mlutil.js');
 const requester = require('./requester');
 const {createGunzip} = require('zlib');
 
@@ -31,20 +31,20 @@ const {createGunzip} = require('zlib');
  */
 function responseDispatcher(response) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   if (!isResponseStatusOkay.call(operation, response)) {
     return;
   }
 
-  var outputMode = operation.outputMode;
+  const outputMode = operation.outputMode;
   if (outputMode === 'none') {
     return;
   }
 
-  var responseType     = response.headers['content-type'];
-  var responseTypeLen  = (!responseType) ? 0 : responseType.length;
-  var responseBoundary = null;
+  const responseType     = response.headers['content-type'];
+  const responseTypeLen  = (!responseType) ? 0 : responseType.length;
+  let responseBoundary = null;
   if (15 <= responseTypeLen && responseType.substr(0, 15) === 'multipart/mixed') {
     responseBoundary = responseType.replace(
         /^multipart.mixed\s*;\s*boundary\s*=\s*([^\s;]+)([\s;].*)?$/, '$1'
@@ -60,16 +60,16 @@ function responseDispatcher(response) {
           );
     }
   }
-  var isMultipart = (responseBoundary != null);
+  const isMultipart = (responseBoundary != null);
 
   // inputHeader may be boundary (for multipart) or content type (for body)
   // Allows dispatch function signatures to remain consistent
-  var inputHeader = isMultipart ? responseBoundary : responseType;
+  const inputHeader = isMultipart ? responseBoundary : responseType;
 
-  var responseLength = response.headers['content-length'];
-  var isEmpty = ((responseLength != null) && responseLength === '0');
+  const responseLength = response.headers['content-length'];
+  const isEmpty = ((responseLength != null) && responseLength === '0');
 
-  var expectedType = operation.responseType;
+  const expectedType = operation.responseType;
 
   // point-in-time operations: if timestamp unset, set with header value
   if (operation.timestamp !== undefined && operation.timestamp !== null) {
@@ -79,7 +79,7 @@ function responseDispatcher(response) {
     }
   }
 
-  var dispatcher = null;
+  let dispatcher = null;
   if (isMultipart) {
     if (expectedType !== 'multipart') {
       operation.logger.debug('expected body but received multipart');
@@ -149,15 +149,15 @@ function CSVDispatcher(operation) {
 CSVDispatcher.prototype.promise = function dispatchCSVPromise(
     contentType, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('csv promise');
-  var collectObject = function collectPromiseBodyObject(data) {
+  const collectObject = function collectPromiseBodyObject(data) {
     operation.data = data;
     resolvedPromise(operation, operation.resolve);
   };
 
-  var isString = operation.copyResponseHeaders(response);
+  const isString = operation.copyResponseHeaders(response);
   if(isResponseGzipped(response.headers)) {
     response.pipe(createGunzip()).pipe(concatStream(
         {encoding: (isString ? 'string' : 'buffer')},
@@ -173,7 +173,7 @@ CSVDispatcher.prototype.promise = function dispatchCSVPromise(
 CSVDispatcher.prototype.chunkedStream = function dispatchCSVChunkedStream(
     contentType, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('csv chunked stream');
 
@@ -196,20 +196,20 @@ function JSONSeqDispatcher(operation) {
 JSONSeqDispatcher.prototype.promise = function dispatchJSONSeqPromise(
   contentType, response
   ) {
-  var operation     = this.operation;
-  var errorListener = operation.errorListener;
-  var objectQueue   = new FifoQueue(2);
-  var parsedObjects = 0;
+  const operation     = this.operation;
+  const errorListener = operation.errorListener;
+  let objectQueue   = new FifoQueue(2);
+  let parsedObjects = 0;
 
   operation.logger.debug('json sequence promise');
 
-  var dataListener = function JSONSeqDataListener(object) {
+  let dataListener = function JSONSeqDataListener(object) {
     parsedObjects++;
     operation.logger.debug('json-seq parsing object %d', parsedObjects);
     objectQueue.addLast(object);
   };
 
-  var finishListener = function JSONSeqFinishListener() {
+  let finishListener = function JSONSeqFinishListener() {
     operation.logger.debug('json-seq finished parsing %d objects', parsedObjects);
     operation.data = objectQueue.getQueue();
     resolvedPromise(operation, operation.resolve);
@@ -248,21 +248,21 @@ JSONSeqDispatcher.prototype.objectStream = function dispatchJSONSeqObjectStream(
 JSONSeqDispatcher.prototype.stream = function dispatchJSONSeqStream(
   streamMode, response
   ) {
-  var operation     = this.operation;
-  var errorListener = operation.errorListener;
-  var outputStream = operation.outputStream;
-  var parsedObjects = 0;
-  var hasParsed = false;
-  var hasEnded = false;
+  const operation     = this.operation;
+  const errorListener = operation.errorListener;
+  const outputStream = operation.outputStream;
+  let parsedObjects = 0;
+  let hasParsed = false;
+  let hasEnded = false;
 
   operation.logger.debug('json sequence stream ' + streamMode);
 
-  var dataListener = function JSONSeqDataListener(object) {
+  let dataListener = function JSONSeqDataListener(object) {
     parsedObjects++;
     operation.logger.debug('parsing object %d', parsedObjects);
     operation.logger.debug(object);
 
-    var writeResult = null;
+    let writeResult = null;
     if (object !== null && object !== undefined) {
       if (streamMode === 'object') {
         writeResult = outputStream.write(object);
@@ -284,7 +284,7 @@ JSONSeqDispatcher.prototype.stream = function dispatchJSONSeqStream(
 
   };
 
-  var responseFinisher = function JSONSeqFinishListener() {
+  let responseFinisher = function JSONSeqFinishListener() {
 
     if (hasParsed && hasEnded) {
       operation.logger.debug('finished parsing %d objects', parsedObjects);
@@ -343,7 +343,7 @@ function BodyDispatcher(operation) {
   this.operation = operation;
 }
 BodyDispatcher.prototype.emptyPromise = function dispatchBodyEmptyPromise(response) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('empty body promise');
 
@@ -351,13 +351,13 @@ BodyDispatcher.prototype.emptyPromise = function dispatchBodyEmptyPromise(respon
   resolvedPromise(operation, operation.resolve);
 };
 BodyDispatcher.prototype.emptyStream = function dispatchBodyEmptyStream(response) {
-  var operation = this.operation;
+  const operation = this.operation;
 
-  var data = operation.emptyHeaderData(response);
+  const data = operation.emptyHeaderData(response);
 
   operation.logger.debug('empty body stream');
 
-  var outputStream = operation.outputStream;
+  const outputStream = operation.outputStream;
   if (data != null) {
     if (operation.outputStreamMode === 'chunked') {
       outputStream.write(JSON.stringify(data));
@@ -370,17 +370,17 @@ BodyDispatcher.prototype.emptyStream = function dispatchBodyEmptyStream(response
 BodyDispatcher.prototype.promise = function dispatchBodyPromise(
     contentType, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('body promise');
-  var collectObject = function collectPromiseBodyObject(data) {
+  const collectObject = function collectPromiseBodyObject(data) {
     // turn collected data into something usable
     // e.g., if JSON, parse as JS object
     operation.data = operation.collectBodyObject(data);
     resolvedPromise(operation, operation.resolve);
   };
 
-  var isString = operation.copyResponseHeaders(response);
+  const isString = operation.copyResponseHeaders(response);
 
   if(isResponseGzipped(response.headers)) {
     const gunzip = createGunzip();
@@ -400,7 +400,7 @@ BodyDispatcher.prototype.promise = function dispatchBodyPromise(
 BodyDispatcher.prototype.chunkedStream = function dispatchBodyChunkedStream(
     contentType, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('body chunked stream');
 
@@ -416,23 +416,23 @@ BodyDispatcher.prototype.chunkedStream = function dispatchBodyChunkedStream(
 BodyDispatcher.prototype.objectStream = function dispatchBodyObjectStream(
     contentType, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
 
   operation.logger.debug('body object stream');
 
   // outputStream is a through2 stream in object mode
-  var outputStream = operation.outputStream;
+  const outputStream = operation.outputStream;
 
-  var collectObject = function collectStreamBodyObject(data) {
+  const collectObject = function collectStreamBodyObject(data) {
     // similar to promise body case, but write to through2
-    var writableObject = operation.collectBodyObject(data);
+    const writableObject = operation.collectBodyObject(data);
     if (writableObject != null) {
       outputStream.write(writableObject);
     }
     outputStream.end();
   };
 
-  var isString = operation.copyResponseHeaders(response);
+  const isString = operation.copyResponseHeaders(response);
   if(isResponseGzipped(response.headers)) {
     response.pipe(createGunzip()).pipe(concatStream(
         {encoding: (isString ? 'string' : 'buffer')},
@@ -458,9 +458,9 @@ function MultipartDispatcher(operation) {
   this.operation = operation;
 }
 MultipartDispatcher.prototype.emptyPromise = function dispatchMultipartEmptyPromise(response) {
-  var operation = this.operation;
+  const operation = this.operation;
 
-  var data = operation.emptyHeaderData(response);
+  const data = operation.emptyHeaderData(response);
 
   operation.logger.debug('empty multipart promise');
 
@@ -468,13 +468,13 @@ MultipartDispatcher.prototype.emptyPromise = function dispatchMultipartEmptyProm
   resolvedPromise(operation, operation.resolve);
 };
 MultipartDispatcher.prototype.emptyStream = function dispatchMultipartEmptyStream(response) {
-  var operation = this.operation;
+  const operation = this.operation;
 
-  var data = operation.emptyHeaderData(response);
+  const data = operation.emptyHeaderData(response);
 
   operation.logger.debug('empty multipart stream');
 
-  var outputStream = operation.outputStream;
+  const outputStream = operation.outputStream;
   if (data != null) {
     if (operation.outputStreamMode === 'chunked') {
       outputStream.write(JSON.stringify(data));
@@ -492,10 +492,10 @@ MultipartDispatcher.prototype.emptyStream = function dispatchMultipartEmptyStrea
 MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
     boundary, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
   operation.logger.debug('multipart promise');
 
-  const errorListenerCheck = (operation.options.headers['Accept'] === 'application/json' && (operation.name.includes('rows') || operation.name.includes('query') || operation.name.includes('/v1/rows')));
+  const errorListenerCheck = (operation.options.headers.Accept === 'application/json' && (operation.name.includes('rows') || operation.name.includes('query') || operation.name.includes('/v1/rows')));
 
   if(errorListenerCheck) {
     if(response.headers['content-encoding']!=='gzip'){
@@ -512,7 +512,7 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
       response.pipe(concatStream(
           {encoding: 'json'},
           () => {
-            let data = JSON.parse(chunks);
+            const data = JSON.parse(chunks);
             operation.data = data;
             resolvedPromise(operation, operation.resolve);
           }
@@ -521,22 +521,22 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
     return;
   }
 
-  var errorListener = operation.errorListener;
+  const errorListener = operation.errorListener;
 
-  var rawHeaderQueue  = new FifoQueue(2);
-  var objectQueue     = new FifoQueue(2);
-  var partReaderQueue = new FifoQueue(3);
+  let rawHeaderQueue  = new FifoQueue(2);
+  let objectQueue     = new FifoQueue(2);
+  let partReaderQueue = new FifoQueue(3);
 
-  var parsingParts = 0;
-  var parsedParts  = 0;
+  let parsingParts = 0;
+  let parsedParts  = 0;
 
-  var hasParsed = false;
-  var hasEnded  = false;
+  let hasParsed = false;
+  let hasEnded  = false;
 
-  var responseFinisher = function promiseResponseFinisher() {
+  let responseFinisher = function promiseResponseFinisher() {
     // If there is metadata left in the buffer, add it to queue
     if (operation.nextMetadataBuffer !== null) {
-      var metadataHeaders = operation.nextMetadataBuffer[0];
+      const metadataHeaders = operation.nextMetadataBuffer[0];
       mlutil.copyProperties(operation.nextMetadataBuffer[1], metadataHeaders);
       objectQueue.addLast(metadataHeaders);
     }
@@ -563,7 +563,7 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
 
     partReaderQueue.removeFirst();
 
-    var madeObject = operation.makeObject(
+    const madeObject = operation.makeObject(
         (data.length === 0) ? null : data, rawHeaderQueue
         );
 
@@ -572,10 +572,10 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
     }
 
     if (partReaderQueue.hasItem()) {
-      var partConcatenator = concatStream(partFinisher);
+      const partConcatenator = concatStream(partFinisher);
       partConcatenator.on('error', errorListener);
 
-      var partReadStream = partReaderQueue.getFirst();
+      const partReadStream = partReaderQueue.getFirst();
       partReadStream.pipe(partConcatenator);
     } else if (hasParsed) {
       responseFinisher();
@@ -597,7 +597,7 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
     partReaderQueue.addLast(partReadStream);
 
     if (partReaderQueue.isLast()) {
-      var partConcatenator = concatStream(partFinisher);
+      const partConcatenator = concatStream(partFinisher);
       partConcatenator.on('error', errorListener);
       partReadStream.pipe(partConcatenator);
     }
@@ -629,19 +629,19 @@ MultipartDispatcher.prototype.promise = function dispatchMultipartPromise(
 MultipartDispatcher.prototype.chunkedStream = function dispatchMultipartChunkedStream(
     boundary, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
   operation.logger.debug('multipart chunked stream');
 
-  var errorListener = operation.errorListener;
+  const errorListener = operation.errorListener;
 
-  var outputStream = operation.outputStream;
+  let outputStream = operation.outputStream;
 
-  var partReaderQueue = new FifoQueue(3);
+  const partReaderQueue = new FifoQueue(3);
 
-  var hasParsed = false;
-  var hasEnded  = false;
+  let hasParsed = false;
+  let hasEnded  = false;
 
-  var responseFinisher = function chunkedResponseFinisher() {
+  let responseFinisher = function chunkedResponseFinisher() {
     outputStream.end();
     outputStream        = null;
     partEndListener     = null;
@@ -656,7 +656,7 @@ MultipartDispatcher.prototype.chunkedStream = function dispatchMultipartChunkedS
     partReaderQueue.removeFirst();
 
     if (partReaderQueue.hasItem()) {
-      var partReadStream = partReaderQueue.getFirst();
+      const partReadStream = partReaderQueue.getFirst();
       partReadStream.pipe(outputStream, {end: false});
     } else if (hasParsed) {
       responseFinisher();
@@ -699,26 +699,26 @@ MultipartDispatcher.prototype.chunkedStream = function dispatchMultipartChunkedS
 MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStream(
     boundary, response
     ) {
-  var operation = this.operation;
+  const operation = this.operation;
   operation.logger.debug('multipart object stream');
 
-  var errorListener   = operation.errorListener;
+  const errorListener   = operation.errorListener;
 
-  var rawHeaderQueue = new FifoQueue(5);
-  var partReaderQueue = new FifoQueue(3);
+  let rawHeaderQueue = new FifoQueue(5);
+  const partReaderQueue = new FifoQueue(3);
 
   // For referenced attachments case
-  var partBuffer = null;
+  let partBuffer = null;
 
-  var parsingParts = 0;
-  var parsedParts  = 0;
+  let parsingParts = 0;
+  let parsedParts  = 0;
 
-  var hasParsed = false;
-  var hasEnded  = false;
+  let hasParsed = false;
+  let hasEnded  = false;
 
-  var isConcatenating = false;
+  let isConcatenating = false;
 
-  var responseFinisher = function objectResponseFinisher() {
+  const responseFinisher = function objectResponseFinisher() {
 
     if (!partReaderQueue.hasItem() && hasParsed && hasEnded) {
 
@@ -734,7 +734,7 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
       else {
         // If there is metadata left in the buffer, write it
         if (operation.nextMetadataBuffer !== null) {
-          var metadataHeaders = operation.nextMetadataBuffer[0];
+          const metadataHeaders = operation.nextMetadataBuffer[0];
           mlutil.copyProperties(operation.nextMetadataBuffer[1], metadataHeaders);
           operation.outputStream.write(metadataHeaders);
           operation.nextMetadataBuffer = null;
@@ -753,16 +753,16 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
 
   };
 
-  var partFinisher = function objectPartFinisher(data) {
+  const partFinisher = function objectPartFinisher(data) {
     parsedParts++;
     operation.logger.debug('parsed part %d', parsedParts);
 
-    var madeObject = operation.makeObject(
+    const madeObject = operation.makeObject(
       (data.length === 0) ? null : data, rawHeaderQueue
     );
 
     // Handle multipart with reference attachments (rows)
-    var writeResult = null;
+    let writeResult = null;
     if (operation.complexValues === 'reference') {
       if (madeObject !== null && madeObject !== undefined) {
         // Columns object
@@ -784,7 +784,7 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
         // Attachment object
         else {
           // Remove '[n]' to get column name
-          var columnName = madeObject.contentId
+          const columnName = madeObject.contentId
             .slice(0, madeObject.contentId.lastIndexOf('['));
           // Put attachment into currently cached part
           partBuffer.content[columnName] = {
@@ -819,9 +819,9 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
     // If item avail, concat-stream it with callback to finisher
     if (partReaderQueue.hasItem()) {
       isConcatenating = true;
-      var partRead = concatStream(partFinisher);
+      const partRead = concatStream(partFinisher);
       partRead.on('error', errorListener);
-      var partReadStream = partReaderQueue.getFirst();
+      const partReadStream = partReaderQueue.getFirst();
       partReadStream.pipe(partRead);
 
     } else if (hasParsed) {
@@ -845,7 +845,7 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
 
     if (partReaderQueue.isLast()) {
       isConcatenating = true;
-      var partRead = concatStream(partFinisher);
+      const partRead = concatStream(partFinisher);
       partRead.on('error', errorListener);
       partReadStream.pipe(partRead);
     }
@@ -861,15 +861,15 @@ MultipartDispatcher.prototype.objectStream = function dispatchMultipartObjectStr
     responseFinisher();
   };
 
-  var drainListener = function objectDrainListener() {
+  const drainListener = function objectDrainListener() {
     if (!hasEnded) {
       response.resume();
       // Don't read if concat in progress to avoid double processing
       if (partReaderQueue.hasItem() && !isConcatenating) {
         isConcatenating = true;
-        var partRead = concatStream(partFinisher);
+        const partRead = concatStream(partFinisher);
         partRead.on('error', errorListener);
-        var partReadStream = partReaderQueue.getFirst();
+        const partReadStream = partReaderQueue.getFirst();
         partReadStream.pipe(partRead);
       }
     }
@@ -951,7 +951,7 @@ FifoQueue.prototype.removeFirst = function fifoRemoveFirst() {
   }
 };
 FifoQueue.prototype.pollFirst = function fifoPollFirst() {
-  var item = this.getFirst();
+  const item = this.getFirst();
   if (item !== undefined) {
     this.removeFirst();
   }
@@ -997,20 +997,20 @@ FifoQueue.prototype.compact = function fifoCompact() {
 
 function isResponseStatusOkay(response) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var statusCode = response.statusCode;
+  const statusCode = response.statusCode;
 
-  var errMsg = null;
+  let errMsg = null;
 
-  var statusCodeValidator = operation.statusCodeValidator;
+  const statusCodeValidator = operation.statusCodeValidator;
   if (typeof statusCodeValidator === 'function') {
     errMsg = statusCodeValidator.call(operation, statusCode, response);
   } else {
-    var validStatusCodes = operation.validStatusCodes;
+    const validStatusCodes = operation.validStatusCodes;
     if (Array.isArray(validStatusCodes)) {
-      var isError = true;
-      for (var i=0; i < validStatusCodes.length; i++) {
+      let isError = true;
+      for (let i=0; i < validStatusCodes.length; i++) {
         if (validStatusCodes[i] === statusCode) {
           isError = false;
           break;
@@ -1025,16 +1025,16 @@ function isResponseStatusOkay(response) {
   }
 
   if (errMsg != null) {
-    var clientError = operation.makeError(errMsg);
+    const clientError = operation.makeError(errMsg);
     clientError.statusCode = statusCode;
     if (statusCode >= 400) {
-      let errorResponse = (isResponseGzipped(response.headers))?response.pipe(createGunzip()):response;
+      const errorResponse = (isResponseGzipped(response.headers))?response.pipe(createGunzip()):response;
       errorResponse.pipe(concatStream(
           {encoding: 'string'},
           function errorBodyDispatcher(body) {
             if (body.length > 0) {
-              var bodyMsg = (typeof body === 'string' || body instanceof String) ? body : body.toString();
-              var contentType = response.headers['content-type'];
+              const bodyMsg = (typeof body === 'string' || body instanceof String) ? body : body.toString();
+              const contentType = response.headers['content-type'];
               clientError.body =
                 ((typeof contentType === 'string' || contentType instanceof String) &&
                     /^application\/([^+]+\+)?json(\s*;.*)?$/.test(contentType)) ?
@@ -1065,7 +1065,7 @@ function ResponseSelector(operation) {
 }
 function operationResultPromise(fullfilled, rejected) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   switch (operation.outputMode) {
   case 'none':
@@ -1080,7 +1080,7 @@ function operationResultPromise(fullfilled, rejected) {
   }
   operation.outputMode = 'promise';
 
-  var promise = new Promise(function promiseDispatcher(resolve, reject) {
+  const promise = new Promise(function promiseDispatcher(resolve, reject) {
     if (operation.done !== true) {
       if (resolve) {
         operation.resolve = resolve;
@@ -1109,9 +1109,9 @@ function resolvedPromise(operation, resolve) {
     return;
   }
 
-  var data    = operation.data;
-  var hasData = (data != null);
-  var dataLen = hasData ? data.length : null;
+  const data    = operation.data;
+  const hasData = (data != null);
+  const dataLen = hasData ? data.length : null;
   if(hasData && dataLen) {
     for(let i=0; i<data.length; i++){
       if(data[i] && data[i].value &&
@@ -1132,17 +1132,17 @@ function resolvedPromise(operation, resolve) {
   }
 }
 function rejectedPromise(operation, reject) {
-  var errorArray = operation.error;
+  const errorArray = operation.error;
   if (!Array.isArray(errorArray)) {
     return false;
   }
 
-  var errorLen = errorArray.length;
+  const errorLen = errorArray.length;
   if (errorLen === 0) {
     return false;
   }
 
-  for (var i=0; i < errorLen; i++) {
+  for (let i=0; i < errorLen; i++) {
     operation.logError(errorArray[i]);
   }
 
@@ -1152,7 +1152,7 @@ function rejectedPromise(operation, reject) {
 
   operation.logger.debug('deferred promise rejecting with '+errorLen+' error messages');
 
-  var firstError = errorArray[0];
+  const firstError = errorArray[0];
   if (errorLen > 1) {
     firstError.otherErrors = errorArray.slice(1);
   }
@@ -1163,7 +1163,7 @@ function rejectedPromise(operation, reject) {
 }
 function operationResultStream() {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   switch (operation.outputMode) {
   case 'none':
@@ -1177,8 +1177,8 @@ function operationResultStream() {
     throw new Error('already created stream');
   }
 
-  var streamArg  = (arguments.length > 0) ? arguments[0] : null;
-  var streamMode = null;
+  const streamArg  = (arguments.length > 0) ? arguments[0] : null;
+  let streamMode = null;
   if (streamArg === null) {
     streamMode = operation.streamDefaultMode;
     operation.outputStreamMode = streamMode;
@@ -1194,7 +1194,7 @@ function operationResultStream() {
   }
   operation.outputMode = streamMode+'Stream';
 
-  var outputStream = null;
+  let outputStream = null;
   switch(streamMode) {
   case 'chunked':
     outputStream = through2();
@@ -1210,9 +1210,9 @@ function operationResultStream() {
   }
   operation.outputStream = outputStream;
 
-  var error = operation.error;
+  const error = operation.error;
   if (error != null) {
-    var i = 0;
+    let i = 0;
     for (; i < error.length; i++) {
       outputStream.emit('error', error[i]);
     }
@@ -1223,7 +1223,7 @@ function operationResultStream() {
 }
 function operationErrorListener(error) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
   if(operation.client.connectionParams.apiKey){
     if(error.statusCode === 401 && operation.expiration <= (new Date())){
       if(!operation.lockAccessToken){
@@ -1245,7 +1245,7 @@ function operationErrorListener(error) {
 
   operation.done = true;
 
-  var outputStream = operation.outputStream;
+  const outputStream = operation.outputStream;
   if (outputStream != null) {
     outputStream.end();
 
diff --git a/lib/rest-server-properties.js b/lib/rest-server-properties.js
index 12f6ab63..ee6c0f43 100644
--- a/lib/rest-server-properties.js
+++ b/lib/rest-server-properties.js
@@ -2,9 +2,9 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /**
  * Provides functions to modify the properties of the REST server for
@@ -28,14 +28,14 @@ function RESTServerProperties(client) {
  * @returns {object} the properties
  */
 RESTServerProperties.prototype.read = function readRESTServerProperties() {
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.headers = {
       'Accept': 'application/json'
   };
   requestOptions.path = '/v1/config/properties';
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read REST server properties', this.client, requestOptions, 'empty', 'single'
       );
 
@@ -45,9 +45,9 @@ RESTServerProperties.prototype.read = function readRESTServerProperties() {
 /** @ignore */
 function RESTServerPropertiesOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var statusCode = operation.responseStatusCode;
+  const statusCode = operation.responseStatusCode;
   return (statusCode === 204 || statusCode === 200);
 }
 
@@ -62,14 +62,14 @@ RESTServerProperties.prototype.write = function writeRESTServerProperties(proper
     throw new Error('cannot write with missing properties object');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'PUT';
   requestOptions.headers = {
       'Content-Type': 'application/json'
   };
   requestOptions.path = '/v1/config/properties';
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write REST server properties', this.client, requestOptions, 'single', 'empty'
       );
   operation.outputTransform = RESTServerPropertiesOutputTransform;
diff --git a/lib/rows.js b/lib/rows.js
index 61dbad31..f24b72b2 100644
--- a/lib/rows.js
+++ b/lib/rows.js
@@ -64,13 +64,13 @@ function Rows(client) {
  * @returns {Promise} A Promise.
  */
 Rows.prototype.query = function queryRows() {
-  let args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   if (args.length < 1) {
     throw new Error('built plan required');
   }
 
-  let builtPlan = args[0],
+  const builtPlan = args[0],
       options = (args.length >= 2) ? args[1] : null;
 
   return queryRowsImpl(this, builtPlan, null, options, args[2]);
@@ -87,12 +87,13 @@ function queryRowsImpl(self, builtPlan, streamType, options, bindingArg, graphql
 }
 
 function queryRowsOperationImpl(self, builtPlan, streamType, options, bindingArg, graphqlQuery) {
+  const validFormats = ['json','xml','csv'],
+        validStructures = ['object','array'],
+        validColumnTypes = ['rows','header'],
+        validComplexValues = ['inline','reference'],
+        validStreamTypes = ['chunked','object','sequence'];
+  
   let sep = '?',
-      validFormats = ['json','xml','csv'],
-      validStructures = ['object','array'],
-      validColumnTypes = ['rows','header'],
-      validComplexValues = ['inline','reference'],
-      validStreamTypes = ['chunked','object','sequence'],
       // set defaults
       format = 'json',
       structure = 'object',
@@ -237,7 +238,7 @@ function queryRowsOperationImpl(self, builtPlan, streamType, options, bindingArg
     }
   }
 
-  let requestOptions = mlutil.newRequestOptions(connectionParams, endpoint, 'POST');
+  const requestOptions = mlutil.newRequestOptions(connectionParams, endpoint, 'POST');
   requestOptions.headers = {
     'Content-Type': contentTypeHeader,
     'Accept': acceptHeader
@@ -291,7 +292,7 @@ function queryContentType(builtPlan, queryType) {
   const validQueryTypes = ['json', 'sparql', 'sql', 'dsl'];
   if (validQueryTypes.indexOf(queryType) < 0) {
     throw new Error('invalid queryType "' + queryType + '"');
-  } else if (queryType != 'json' && typeof builtPlan != 'string' && !(builtPlan instanceof String)) {
+  } else if (queryType != 'json' && typeof builtPlan !== 'string' && !(builtPlan instanceof String)) {
     throw new Error('queryType "' + queryType + '" must be provided as string');
   }
 
@@ -318,15 +319,15 @@ function queryContentType(builtPlan, queryType) {
  * @returns {ReadableStream} A readable stream.
  */
 Rows.prototype.queryAsStream = function queryAsStreamRows() {
-  let args = mlutil.asArray.apply(null, arguments),
-      streamType = 'chunked', // default
+  const args = mlutil.asArray.apply(null, arguments);
+  let streamType = 'chunked', // default
       options = null;
 
   if (args.length < 1) {
     throw new Error('built plan required');
   }
 
-  let builtPlan = args[0];
+  const builtPlan = args[0];
 
   if (args.length === 2) {
     if (typeof args[1] === 'string' || args[1] instanceof String) {
@@ -414,7 +415,7 @@ Rows.prototype.generateView = function generateViewRows(builtPlan, schema, view,
     throw new Error('view cannot be null or empty');
   }
 
-  let acceptHeader = 'application/xml';
+  const acceptHeader = 'application/xml';
 
   const contentTypeHeader = queryContentType(builtPlan, queryType);
   const endpoint = '/v1/rows?output=generateView&schemaName='+schema+'&viewName='+view;
@@ -475,7 +476,7 @@ Rows.prototype.generateView = function generateViewRows(builtPlan, schema, view,
  */
  Rows.prototype.queryAll = function queryAllDocumentsImpl(batchView, jobOptions){
 
-   let path = '/v1/internal/viewinfo';
+   const path = '/v1/internal/viewinfo';
    const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'POST');
 
    requestOptions.headers = {
@@ -483,7 +484,7 @@ Rows.prototype.generateView = function generateViewRows(builtPlan, schema, view,
      'Content-Type': 'application/json'
    };
 
-   let operation = new Operation(
+   const operation = new Operation(
        'read viewInfo', this.client, requestOptions, 'single', 'single'
    );
    if (batchView instanceof planBuilder.Plan) {
@@ -492,7 +493,7 @@ Rows.prototype.generateView = function generateViewRows(builtPlan, schema, view,
      operation.requestBody = batchView;
    }
 
-   let jobState = {
+   const jobState = {
      docInstance : this,
      requesterCount: 0,
      rowsReadSuccessfully:0,
@@ -623,26 +624,26 @@ Rows.prototype.generateView = function generateViewRows(builtPlan, schema, view,
  */
 
 Rows.prototype.execute = function executeRows() {
-  let args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   if (args.length < 1) {
     throw new Error('built plan required');
   }
 
-  let builtPlan = args[0], options = (args.length >= 2 && args[1])?args[1] : {};
+  const builtPlan = args[0], options = (args.length >= 2 && args[1])?args[1] : {};
   // opticExecute is an internal flag to ensure output doesn't default to anything.
   options.opticExecute = true;
   queryRowsImpl(this, builtPlan, null, options, args[2]);
 };
 
 Rows.prototype.graphQL = function graphqlRows() {
-  let args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   if (args.length < 1) {
     throw new Error('graphql query required');
   }
 
-  let options = (args.length >= 2) ? args[1] : null;
+  const options = (args.length >= 2) ? args[1] : null;
 
   return queryRowsImpl(this, null, null, options,null, args[0]);
 };
@@ -702,10 +703,10 @@ function onQueryAllRows(jobState, readerId, batchNum) {
     finishOnQueryAllRows(jobState);
     return;
   }
-  let lowerBound = bigInt((currentBatchNum - 1) * jobState.requestBatchSize);
-  let upperBound = (currentBatchNum === jobState.numberOfBatches) ? '-1' :
+  const lowerBound = bigInt((currentBatchNum - 1) * jobState.requestBatchSize);
+  const upperBound = (currentBatchNum === jobState.numberOfBatches) ? '-1' :
       bigInt(lowerBound + jobState.requestBatchSize -1);
-  let options = {
+  const options = {
     bindings: {ML_LOWER_BOUND:lowerBound, ML_UPPER_BOUND:upperBound},
     format: jobState.jobOptions.rowFormat,
     structure: jobState.jobOptions.rowStructure,
diff --git a/lib/server-exec.js b/lib/server-exec.js
index ddf1a40b..cc934500 100644
--- a/lib/server-exec.js
+++ b/lib/server-exec.js
@@ -2,10 +2,10 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var qs        = require('qs');
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const qs        = require('qs');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 function execOutputTransform(headers, data) {
   /*jshint validthis:true */
@@ -13,7 +13,7 @@ function execOutputTransform(headers, data) {
     return [];
   }
 
-  var contentType = headers['content-type'][0];
+  let contentType = headers['content-type'][0];
   if (typeof contentType === 'string' || contentType instanceof String) {
     contentType = contentType.replace(/;.*$/, '');
   }
@@ -39,8 +39,8 @@ function execOutputTransform(headers, data) {
     };
   }
 
-  var primitive = headers['x-primitive'][0];
-  var value     = null;
+  const primitive = headers['x-primitive'][0];
+  let value     = null;
   switch(primitive) {
   case 'node()':
     return {
@@ -102,7 +102,7 @@ function execOutputTransform(headers, data) {
   case 'unsignedLong':
     value = data.content;
     if (isFinite(value)) {
-      var number = Number(value);
+      const number = Number(value);
       if (Math.abs(number) < 9007199254740992) {
         value = number;
       }
@@ -224,10 +224,10 @@ function serverInvoke() {
 /** @ignore */
 function serverExec(execName, args) {
   /*jshint validthis:true */
-  var client = this;
+  const client = this;
 
-  var operationDesc = null;
-  var execType = null;
+  let operationDesc = null;
+  let execType = null;
   if (execName === 'invoke') {
     operationDesc = 'invoke code on server';
     execType = execName;
@@ -240,13 +240,13 @@ function serverExec(execName, args) {
     throw new Error('must specify the source to '+operationDesc);
   }
 
-  var isInvoke = (execType === 'invoke');
+  const isInvoke = (execType === 'invoke');
 
-  var arg = args[0];
+  const arg = args[0];
 
-  var source    = isInvoke ? arg.path : arg.source;
-  var variables = null;
-  var txid      = null;
+  let source    = isInvoke ? arg.path : arg.source;
+  let variables = null;
+  let txid      = null;
   if (source !== void 0) {
     variables = arg.variables;
     txid      = mlutil.convertTransaction(arg.txid);
@@ -257,7 +257,7 @@ function serverExec(execName, args) {
     }
   }
 
-  var body = {};
+  const body = {};
   if (isInvoke) {
     body.module = source;
   } else {
@@ -267,8 +267,8 @@ function serverExec(execName, args) {
     body.vars = JSON.stringify(variables);
   }
 
-  var endpoint = isInvoke? '/v1/invoke' : '/v1/eval';
-  var sep = '?';
+  let endpoint = isInvoke? '/v1/invoke' : '/v1/eval';
+  let sep = '?';
   if (txid != null) {
     endpoint += sep+'txid='+mlutil.getTxidParam(txid);
     sep = '&';
@@ -281,7 +281,7 @@ function serverExec(execName, args) {
   };
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       operationDesc, client, requestOptions, 'single', 'multipart'
       );
   operation.requestBody     = qs.stringify(body);
diff --git a/lib/transactions.js b/lib/transactions.js
index a4a28ac7..f010ef4c 100644
--- a/lib/transactions.js
+++ b/lib/transactions.js
@@ -2,9 +2,9 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /**
  * Provides functions to open, commit, or rollback multi-statement
@@ -16,9 +16,9 @@ var Operation = require('./operation.js');
 /** @ignore */
 function openOutputTransform(headers/*, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var txid = headers.location.substring('/v1/transactions/'.length);
+  const txid = headers.location.substring('/v1/transactions/'.length);
 
   if (operation.withState === true) {
     return new mlutil.Transaction(txid, operation.rawHeaders['set-cookie']);
@@ -57,17 +57,17 @@ function Transactions(client) {
  * will be removed in the next major release.
  */
 Transactions.prototype.open = function openTransaction() {
-  var args   = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args   = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
-  var transactionName = null;
-  var timeLimit       = null;
-  var withState       = null;
+  let transactionName = null;
+  let timeLimit       = null;
+  let withState       = null;
 
-  var arg = (argLen > 0) ? args[0] : null;
+  let arg = (argLen > 0) ? args[0] : null;
   if (argLen > 1 || (typeof arg === 'string' || arg instanceof String) || (typeof arg === 'number' || arg instanceof Number) ||
       (typeof arg === 'boolean')) {
-    var i=0;
+    let i=0;
     for (; i < argLen; i++) {
       arg = args[i];
       if (transactionName === null && (typeof arg === 'string' || arg instanceof String)) {
@@ -88,8 +88,8 @@ Transactions.prototype.open = function openTransaction() {
     withState       = arg.withState;
   }
 
-  var path = '/v1/transactions';
-  var sep = '?';
+  let path = '/v1/transactions';
+  let sep = '?';
   if (transactionName != null) {
     path += sep+'name='+encodeURIComponent(transactionName);
     sep = '&';
@@ -100,7 +100,7 @@ Transactions.prototype.open = function openTransaction() {
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'POST');
 
-  var operation = new Operation(
+  const operation = new Operation(
       'open transaction', this.client, requestOptions, 'empty', 'empty'
       );
   operation.validStatusCodes = [303];
@@ -121,8 +121,8 @@ Transactions.prototype.open = function openTransaction() {
  * @returns {object} information about the transaction
  */
 Transactions.prototype.read = function readTransaction(txidRaw) {
-  var txid = mlutil.convertTransaction(txidRaw);
-  var path =
+  const txid = mlutil.convertTransaction(txidRaw);
+  const path =
     '/v1/transactions/'+mlutil.getTxidParam(txid, 'read')+'?format=json';
 
   const requestOptions = mlutil.newRequestOptions(this.client.getConnectionParams(), path, 'GET');
@@ -131,7 +131,7 @@ Transactions.prototype.read = function readTransaction(txidRaw) {
   };
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read transaction', this.client, requestOptions, 'empty', 'single'
       );
   operation.txid = txid;
@@ -166,7 +166,7 @@ Transactions.prototype.rollback = function rollbackTransaction(txid) {
 /** @ignore */
 function finishOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   return {
     txid:     operation.txid,
@@ -175,14 +175,14 @@ function finishOutputTransform(/*headers, data*/) {
 }
 /** @ignore */
 function finishTransaction(client, result, txidRaw) {
-  var txid = mlutil.convertTransaction(txidRaw);
-  var path =
+  const txid = mlutil.convertTransaction(txidRaw);
+  const path =
     '/v1/transactions/'+mlutil.getTxidParam(txid, result)+'?result='+result;
 
   const requestOptions = mlutil.newRequestOptions(client.getConnectionParams(), path, 'POST');
   mlutil.addTxidHeaders(requestOptions, txid);
 
-  var operation = new Operation(
+  const operation = new Operation(
       result+' transaction', client, requestOptions, 'empty', 'empty'
       );
   operation.txid             = txid;
diff --git a/lib/transforms.js b/lib/transforms.js
index 1a69e2fb..e3c5338d 100644
--- a/lib/transforms.js
+++ b/lib/transforms.js
@@ -2,16 +2,16 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /** @ignore */
 function nameErrorTransform(message) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
-  var name = operation.name;
+  const name = operation.name;
   return (name == null) ? message :
     (message+' (on '+name+' transform)');
 }
@@ -26,7 +26,7 @@ function nameErrorTransform(message) {
 /** @ignore */
 function emptyOutputTransform(/*headers, data*/) {
   /*jshint validthis:true */
-  var operation = this;
+  const operation = this;
 
   return {
     name: operation.name
@@ -59,11 +59,11 @@ Transforms.prototype.read = function readTransform(name) {
     throw new Error('must specify name when reading the transform source');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.path = '/v1/config/transforms/'+encodeURIComponent(name);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'read transform', this.client, requestOptions, 'empty', 'single'
       );
   operation.name           = name;
@@ -82,21 +82,21 @@ Transforms.prototype.read = function readTransform(name) {
  * @param {object|string} source - the source for the transform
  */
 Transforms.prototype.write = function writeTransform() {
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen === 0) {
     throw new Error('no arguments for writing an extension library');
   }
 
-  var name        = null;
-  var title       = null;
-  var description = null;
-  var provider    = null;
-  var version     = null;
-  var format      = null;
-  var source      = null;
+  let name        = null;
+  let title       = null;
+  let description = null;
+  let provider    = null;
+  let version     = null;
+  let format      = null;
+  let source      = null;
 
-  var params      = null;
+  let params      = null;
   if (argLen === 1) {
     params = args[0];
     name        = params.name;
@@ -117,7 +117,7 @@ Transforms.prototype.write = function writeTransform() {
     throw new Error('must specify name, format, and source when writing a transform');
   }
 
-  var contentType = null;
+  let contentType = null;
   switch(format) {
   case 'javascript':
     contentType = 'application/javascript';
@@ -132,9 +132,9 @@ Transforms.prototype.write = function writeTransform() {
     throw new Error('unsupported transform format '+format);
   }
 
-  var endpoint = '/v1/config/transforms/'+encodeURIComponent(name);
+  let endpoint = '/v1/config/transforms/'+encodeURIComponent(name);
 
-  var sep = '?';
+  let sep = '?';
   if (title != null) {
     endpoint += sep+'title='+encodeURIComponent(title);
     if (sep === '?') {sep = '&';}
@@ -152,14 +152,14 @@ Transforms.prototype.write = function writeTransform() {
     if (sep === '?') {sep = '&';}
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'PUT';
   requestOptions.headers = {
       'Content-Type': contentType
   };
   requestOptions.path = endpoint;
 
-  var operation = new Operation(
+  const operation = new Operation(
       'write transform', this.client, requestOptions, 'single', 'empty'
       );
   operation.name            = name;
@@ -181,11 +181,11 @@ Transforms.prototype.remove = function removeTransform(name) {
     throw new Error('must specify name when deleting the transform source');
   }
 
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'DELETE';
   requestOptions.path = '/v1/config/transforms/'+encodeURIComponent(name);
 
-  var operation = new Operation(
+  const operation = new Operation(
       'remove transform', this.client, requestOptions, 'empty', 'empty'
       );
   operation.name            = name;
@@ -204,14 +204,14 @@ Transforms.prototype.remove = function removeTransform(name) {
  * on the server
  */
 Transforms.prototype.list = function listTransforms() {
-  var requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
+  const requestOptions = mlutil.copyProperties(this.client.getConnectionParams());
   requestOptions.method = 'GET';
   requestOptions.headers = {
       'Accept': 'application/json'
   };
   requestOptions.path = '/v1/config/transforms';
 
-  var operation = new Operation(
+  const operation = new Operation(
       'list transforms', this.client, requestOptions, 'empty', 'single'
       );
 
diff --git a/lib/values-builder.js b/lib/values-builder.js
index b3b4d890..4c93caff 100644
--- a/lib/values-builder.js
+++ b/lib/values-builder.js
@@ -4,8 +4,8 @@
 'use strict';
 
 
-var mlutil = require('./mlutil.js');
-var qb     = require('./query-builder.js').builder;
+const mlutil = require('./mlutil.js');
+const qb     = require('./query-builder.js').builder;
 
 /**
  * A source of datatyped values from a JSON property,
@@ -113,18 +113,18 @@ function ValueBuilder() {
  */
 function valuesFromIndexes() {
   /*jshint validthis:true */
-  var self = (this instanceof ValueBuilder) ? this : new ValueBuilder();
+  const self = (this instanceof ValueBuilder) ? this : new ValueBuilder();
 
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
 
-  var isRangeIndex = {
+  const isRangeIndex = {
     'element':       true,
     'field':         true,
     'json-property': true,
     'path-index':    true
   };
-  var isGeoLocationIndex = {
+  const isGeoLocationIndex = {
     'geo-attr-pair':          true,
     'geo-elem':               true,
     'geo-elem-pair':          true,
@@ -133,10 +133,10 @@ function valuesFromIndexes() {
     'geo-path':               true
   };
 
-  var arg      = null;
-  var firstKey = null;
-  var range    = null;
-  for (var i=0; i < argLen; i++) {
+  let arg      = null;
+  let firstKey = null;
+  let range    = null;
+  for (let i=0; i < argLen; i++) {
     arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       args[i] = {range: qb.property(arg)};
@@ -174,15 +174,15 @@ ValueBuilder.prototype.fromIndexes = valuesFromIndexes;
  * @returns {valuesBuilder.BuiltQuery} a built query
  */
 ValueBuilder.prototype.where = function valuesWhere() {
-  var self = this;
+  const self = this;
 
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   // TODO: if empty, clear the clause
 
-  var parsedQuery = null;
-  var fragmentScope = null;
-  var queries = null;
+  let parsedQuery = null;
+  let fragmentScope = null;
+  let queries = null;
 
   switch(argLen) {
   case 0:
@@ -190,8 +190,8 @@ ValueBuilder.prototype.where = function valuesWhere() {
     self.whereClause = {query: {queries: [qb.and()]}};
     break;
   default:
-    for (var i=0; i < argLen; i++) {
-      var arg = args[i];
+    for (let i=0; i < argLen; i++) {
+      const arg = args[i];
       if (parsedQuery == null) {
         parsedQuery = arg.parsedQuery;
         if (parsedQuery != null) {
@@ -244,17 +244,17 @@ ValueBuilder.prototype.where = function valuesWhere() {
  * @returns {valuesBuilder.BuiltQuery} a built query
  */
 ValueBuilder.prototype.aggregates = function valuesAggregates() {
-  var self = this;
+  const self = this;
 
-  var args = mlutil.asArray.apply(null, arguments);
-  var argLen = args.length;
+  const args = mlutil.asArray.apply(null, arguments);
+  const argLen = args.length;
   if (argLen < 1) {
     throw new Error('aggregates must specify at least one built-in function or UDF');
   }
 
-  var aggregateFunctions = [];
-  for (var i=0; i < argLen; i++) {
-    var arg = args[i];
+  const aggregateFunctions = [];
+  for (let i=0; i < argLen; i++) {
+    const arg = args[i];
     if (typeof arg === 'string' || arg instanceof String) {
       aggregateFunctions.push({apply:arg});
     } else if (arg.udf !== void 0) {
@@ -318,9 +318,9 @@ function udf() {
  * @returns {valuesBuilder.BuiltQuery} a built query
  */
 ValueBuilder.prototype.slice = function valuesSlice() {
-  var self = this;
+  const self = this;
 
-  var args = mlutil.asArray.apply(null, arguments);
+  const args = mlutil.asArray.apply(null, arguments);
 
   // TODO: if empty, clear the clause
 
@@ -342,23 +342,23 @@ ValueBuilder.prototype.slice = function valuesSlice() {
  * @returns {valuesBuilder.BuiltQuery} a built query
  */
 ValueBuilder.prototype.withOptions = function valuesWithOptions() {
-  var self = this;
+  const self = this;
 
   // TODO: share with values.js
-  var optionKeyMapping = {
+  const optionKeyMapping = {
       values:      'values-option',
       forestNames: 'forest-names'
   };
 
   // TODO: reuse key copy logic with query-build withOptions
-  var withOptionsClause = {};
+  const withOptionsClause = {};
   if (0 < arguments.length) {
-    var arg = arguments[0];
-    var argKeys = Object.keys(arg);
-    for (var i=0; i < argKeys.length; i++) {
-      var key = argKeys[i];
+    const arg = arguments[0];
+    const argKeys = Object.keys(arg);
+    for (let i=0; i < argKeys.length; i++) {
+      const key = argKeys[i];
       if (optionKeyMapping[key] !== undefined) {
-        var value = arg[key];
+        const value = arg[key];
         if (value !== undefined) {
           withOptionsClause[key] = value;
         }
@@ -393,20 +393,20 @@ function valuesUri() {
  * @returns {valuesBuilder.BuiltQuery} a built query
  */
 function copyFromValueBuilder(otherValueBuilder) {
-  var tb = new ValueBuilder();
+  const tb = new ValueBuilder();
 
   // TODO: share with QueryBuilder
   if (otherValueBuilder != null) {
-    var clauseKeys = [
+    const clauseKeys = [
       'fromIndexesClause', 'whereClause',      'aggregatesClause',
       'sliceClause',       'withOptionsClause'
     ];
-    var isString = (typeof otherValueBuilder === 'string' || otherValueBuilder instanceof String);
-    var other = isString ?
+    const isString = (typeof otherValueBuilder === 'string' || otherValueBuilder instanceof String);
+    const other = isString ?
         JSON.parse(otherValueBuilder) : otherValueBuilder;
-    for (var i=0; i < clauseKeys.length; i++){
-      var key = clauseKeys[i];
-      var value = other[key];
+    for (let i=0; i < clauseKeys.length; i++){
+      const key = clauseKeys[i];
+      const value = other[key];
       if (value != null) {
         // structuredClone instead of clone to avoid preserving prototype
         tb[key] = isString ? value : structuredClone(value);
diff --git a/lib/values.js b/lib/values.js
index 7290f728..308dfbd1 100644
--- a/lib/values.js
+++ b/lib/values.js
@@ -2,9 +2,9 @@
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
 'use strict';
-var requester = require('./requester.js');
-var mlutil    = require('./mlutil.js');
-var Operation = require('./operation.js');
+const requester = require('./requester.js');
+const mlutil    = require('./mlutil.js');
+const Operation = require('./operation.js');
 
 /**
  * Provides functions to project tuples (aka rows) of values out of documents.
@@ -40,9 +40,9 @@ Values.prototype.read = function readValues() {
   if (arguments.length === 0 || arguments.length > 2) {
     throw new Error('incorrect number of arguments to read values');
   }
-  var arg = arguments[0];
+  const arg = arguments[0];
 
-  var timestamp = null;
+  let timestamp = null;
   if (arguments.length === 2) {
     if (arguments[1] instanceof mlutil.Timestamp) {
       timestamp = arguments[1];
@@ -51,49 +51,49 @@ Values.prototype.read = function readValues() {
     }
   }
 
-  var structuredef = {
+  const structuredef = {
     name:  'structuredef',
     style: 'consistent'
   };
 
-  var indexesClause = arg.fromIndexesClause;
-  var indexesLength = Array.isArray(indexesClause) ? indexesClause.length : 0;
+  const indexesClause = arg.fromIndexesClause;
+  const indexesLength = Array.isArray(indexesClause) ? indexesClause.length : 0;
   if (indexesLength < 1) {
     throw new Error('must specify indexes to read values');
   }
 
-  var isValues      = (indexesLength === 1);
-  var structureName = isValues ? 'values' : 'tuples';
+  const isValues      = (indexesLength === 1);
+  const structureName = isValues ? 'values' : 'tuples';
 
   if (isValues) {
-    var indexObject        = indexesClause[0];
-    var indexKey           = Object.keys(indexObject)[0];
+    const indexObject        = indexesClause[0];
+    const indexKey           = Object.keys(indexObject)[0];
     structuredef[indexKey] = indexObject[indexKey];
   } else {
     structuredef.indexes = indexesClause;
   }
 
-  var aggregatesClause = arg.aggregatesClause;
+  const aggregatesClause = arg.aggregatesClause;
   if (aggregatesClause !== void 0) {
     structuredef.aggregate = aggregatesClause.aggregates;
   }
 
-  var structureOptions = {};
+  const structureOptions = {};
   structureOptions[structureName] = [structuredef];
 
-  var withOptionsClause = arg.withOptionsClause;
+  const withOptionsClause = arg.withOptionsClause;
   if (withOptionsClause !== void 0) {
     // TODO: share with value-builder.js
-    var optionKeyMapping = {
+    const optionKeyMapping = {
         values:      'values-option',
         forestNames: 'forest-names'
     };
 
-    var optionsKeys = Object.keys(withOptionsClause);
-    var key = null;
-    var mapping = null;
-    var value = null;
-    for (var i=0; i < optionsKeys.length; i++) {
+    const optionsKeys = Object.keys(withOptionsClause);
+    let key = null;
+    let mapping = null;
+    let value = null;
+    for (let i=0; i < optionsKeys.length; i++) {
       key = optionsKeys[i];
       mapping = optionKeyMapping[key];
       if (mapping !== void 0) {
@@ -109,23 +109,23 @@ Values.prototype.read = function readValues() {
     }
   }
 
-  var searchBody = {
+  const searchBody = {
       options: structureOptions
   };
 
-  var whereClause = arg.whereClause;
+  const whereClause = arg.whereClause;
   if (whereClause != null) {
-    var query         = whereClause.query;
-    var parsedQuery   = whereClause.parsedQuery;
-    var fragmentScope = whereClause['fragment-scope'];
+    const query         = whereClause.query;
+    const parsedQuery   = whereClause.parsedQuery;
+    const fragmentScope = whereClause['fragment-scope'];
     if (query != null) {
       searchBody.query = query;
     }
     if (parsedQuery != null) {
       searchBody.qtext = parsedQuery.qtext;
 
-      var constraintBindings = parsedQuery.constraint;
-      var termBinding        = parsedQuery.term;
+      const constraintBindings = parsedQuery.constraint;
+      const termBinding        = parsedQuery.term;
       if (constraintBindings != null) {
         structureOptions.constraint = constraintBindings;
       }
@@ -138,17 +138,17 @@ Values.prototype.read = function readValues() {
     }
   }
 
-  var pageStart  = null;
-  var pageLength = null;
-  var transform  = null;
+  let pageStart  = null;
+  let pageLength = null;
+  let transform  = null;
 
-  var sliceClause = arg.sliceClause;
+  const sliceClause = arg.sliceClause;
   if (sliceClause !== void 0) {
-    var sliceStart = sliceClause['page-start'];
+    const sliceStart = sliceClause['page-start'];
     if (sliceStart !== void 0) {
       pageStart = sliceStart;
     }
-    var sliceLength = sliceClause['page-length'];
+    const sliceLength = sliceClause['page-length'];
     if (sliceLength !== void 0) {
       pageLength = sliceLength;
     }
@@ -156,7 +156,7 @@ Values.prototype.read = function readValues() {
     transform = sliceClause['document-transform'];
   }
 
-  var endpoint = '/v1/values/structuredef?format=json';
+  let endpoint = '/v1/values/structuredef?format=json';
 
   if (pageStart !== null) {
     endpoint += '&start='+pageStart;
@@ -180,7 +180,7 @@ Values.prototype.read = function readValues() {
       'Accept':       'application/json'
   };
 
-  var operation = new Operation(
+  const operation = new Operation(
       'query values', this.client, requestOptions, 'single', 'single'
       );
   operation.validStatusCodes = [200, 204];
diff --git a/lib/www-authenticate-patched/md5.js b/lib/www-authenticate-patched/md5.js
index ba61d430..10a5df0f 100644
--- a/lib/www-authenticate-patched/md5.js
+++ b/lib/www-authenticate-patched/md5.js
@@ -9,7 +9,7 @@
 /*
 * Copyright (c) 2015-2025 Progress Software Corporation and/or its subsidiaries or affiliates. All Rights Reserved.
 */
-var crypto= require('crypto');
+const crypto= require('crypto');
 
 function md5(s) {
   return crypto.createHash('md5').update(s).digest('hex');
diff --git a/lib/www-authenticate-patched/parsers.js b/lib/www-authenticate-patched/parsers.js
index 1bda7820..6998fc40 100644
--- a/lib/www-authenticate-patched/parsers.js
+++ b/lib/www-authenticate-patched/parsers.js
@@ -10,25 +10,25 @@
  * Licensed under the MIT license.
  */
 
-var ParseAuth= /(\w+)\s+(.*)/  // -> scheme, params
+const ParseAuth= /(\w+)\s+(.*)/  // -> scheme, params
   , Separators= /([",=])/
   ;
 
 function parse_params(header) {
   // This parser will definitely fail if there is more than one challenge
-  var tok, _i, _len, key, value;
-  var state= 0;   //0: token,
-  var m= header.split(Separators)
+  let tok, _i, _len, key, value;
+  let state= 0;   //0: token,
+  const m= header.split(Separators);
   for (_i = 0, _len = m.length; _i < _len; _i++) {
     tok = m[_i];
-    if (!tok.length) continue;
+    if (!tok.length) {continue;}
     switch (state) {
       case 0: // token
         key= tok.trim();
         state= 1; // expect equals
         continue;
       case 1: // expect equals
-        if ('=' != tok) return 'Equal sign was expected after '+key;
+        if ('=' != tok) {return 'Equal sign was expected after '+key;}
         state= 2;
         continue;
       case 2: // expect value
@@ -68,7 +68,7 @@ function parse_params(header) {
           return 'Unexpected token ('+tok+') after '+value+'"';
         }
       case 9: // expect commma
-        if (',' != tok) return 'Comma expected after '+value;
+        if (',' != tok) {return 'Comma expected after '+value;}
         state= 0;
         continue;
     }
@@ -87,10 +87,10 @@ function parse_params(header) {
 
 function Parse_WWW_Authenticate(to_parse)
 {
-  var m= to_parse.match(ParseAuth);
+  const m= to_parse.match(ParseAuth);
   this.scheme= m[1];
   this.parms= {};
-  var err= this.parse_params(m[2]);
+  const err= this.parse_params(m[2]);
   if (err) {
     this.scheme= '';
     this.parms= {};
@@ -102,7 +102,7 @@ function Parse_Authentication_Info(to_parse)
 {
   this.scheme= 'Digest';
   this.parms= {};
-  var err= this.parse_params(to_parse);
+  const err= this.parse_params(to_parse);
   if (err) {
     this.scheme= '';
     this.parms= {};
diff --git a/lib/www-authenticate-patched/user-credentials.js b/lib/www-authenticate-patched/user-credentials.js
index e9128a3a..3d3555af 100644
--- a/lib/www-authenticate-patched/user-credentials.js
+++ b/lib/www-authenticate-patched/user-credentials.js
@@ -11,7 +11,7 @@
  */
 
 
-var md5= require('./md5');
+const md5= require('./md5');
 
 /*
  * Hide the password. Uses the password to form authorization strings,
@@ -25,14 +25,14 @@ function user_credentials(username,password,options) {
     return username;
   }
 
-  var basic_string= options && options.hide_basic ?
+  const basic_string= options && options.hide_basic ?
     ''
     :
       (!password && password !== '' ?
         Buffer.from(username, 'ascii').toString('base64')
       :
         Buffer.from(username+':'+password, 'ascii').toString('base64')
-      )
+      );
   function Credentials()
   {
     this.username= username;
@@ -40,18 +40,18 @@ function user_credentials(username,password,options) {
   Credentials.prototype.basic= function()
   {
     return basic_string;
-  }
+  };
   Credentials.prototype.digest= function(realm)
   {
     return !password && password !== '' ?
         md5(username+':'+realm)
         :
-        md5(username+':'+realm+':'+password)
-  }
+        md5(username+':'+realm+':'+password);
+  };
   Credentials.prototype.is_user_credentials= function()
   {
     return true;
-  }
+  };
 
   return new Credentials;
 }
diff --git a/lib/www-authenticate-patched/www-authenticate.js b/lib/www-authenticate-patched/www-authenticate.js
index f4d818ac..5b85f9f7 100644
--- a/lib/www-authenticate-patched/www-authenticate.js
+++ b/lib/www-authenticate-patched/www-authenticate.js
@@ -12,7 +12,7 @@
 
 'use strict';
 
-var crypto= require('crypto')
+const crypto= require('crypto')
   , parsers= require('./parsers')
   , md5= require('./md5')
   , user_credentials= require('./user-credentials')
@@ -29,32 +29,32 @@ function hex8(num)
   return ('00000000' + num.toString(16)).slice(-8);
 }
 
-var www_authenticator = function(username,password,options)
+const www_authenticator = function(username,password,options)
 {
   if (2 == arguments.length && toString.call(password) != '[object String]') {
     options= password;
     password= null;
   }
-  var credentials= user_credentials(username,password)
-  var cnonce;
+  const credentials= user_credentials(username,password);
+  let cnonce;
   if (options) {
     if (toString.call(options.cnonce) == '[object String]')
-      cnonce= options.cnonce;
+      {cnonce= options.cnonce;}
   }
-  if (cnonce === void 0) cnonce= crypto.pseudoRandomBytes(8).toString('hex');
-  var parse_header= function(www_authenticate)
+  if (cnonce === void 0) {cnonce= crypto.pseudoRandomBytes(8).toString('hex');}
+  const parse_header= function(www_authenticate)
   {
     function Authenticator()
     {
       function note_error(err)
       {
-        this.err= err
+        this.err= err;
       }
-      var nc= 0;
+      let nc= 0;
 
-      var parsed= new parsers.WWW_Authenticate(www_authenticate);
-      if (parsed.err) return note_error(parsed.err);
-      var auth_parms= this.parms= parsed.parms;
+      const parsed= new parsers.WWW_Authenticate(www_authenticate);
+      if (parsed.err) {return note_error(parsed.err);}
+      const auth_parms= this.parms= parsed.parms;
       this.cnonce= cnonce;
 
       switch(parsed.scheme) {
@@ -83,7 +83,7 @@ var www_authenticator = function(username,password,options)
           var qop= auth_parms.qop;
           if (!qop) {
               this.authorize= function(method,digestURI) {
-                var ha2= md5(method+':'+digestURI);
+                const ha2= md5(method+':'+digestURI);
                 return fixed+
                   ' uri="'+digestURI+'",'+
                   ' response="'+md5(ha1+':'+nonce+':'+ha2)+'",';
@@ -91,12 +91,12 @@ var www_authenticator = function(username,password,options)
               return;
           }
           else {
-            var qopa= qop.split(',');
-            var _i, _len;
+            const qopa= qop.split(',');
+            let _i, _len;
             for (_i = 0, _len = qopa.length; _i < _len; _i++) {
               if ('auth' === qopa[_i]) {
                 var opaque= auth_parms.opaque;
-                var algorithm= auth_parms.algorithm;
+                let algorithm= auth_parms.algorithm;
                 if (algorithm) {
                   fixed+= ' algorithm="'+algorithm+'",';
                 }
@@ -108,10 +108,10 @@ var www_authenticator = function(username,password,options)
                   :
                   ha1;
                 this.authorize= function(method,digestURI) {
-                  var ha2= md5(method+':'+digestURI);
+                  const ha2= md5(method+':'+digestURI);
                   nc= nc+1;
-                  var hexed_nc= hex8(nc);
-                  var s= fixed+
+                  const hexed_nc= hex8(nc);
+                  let s= fixed+
                     ' uri="'+digestURI+'",'+
                     ' qop=auth,'+
                     ' nc='+hexed_nc+','+
@@ -142,8 +142,8 @@ var www_authenticator = function(username,password,options)
 
 function HigherLevel(credentials,options)
 {
-  this.credentials= credentials
-  this.options= options
+  this.credentials= credentials;
+  this.options= options;
   if (options && options.sendImmediately) {
     this.sendImmediately= true;
   }
@@ -151,42 +151,42 @@ function HigherLevel(credentials,options)
 HigherLevel.prototype.get_challenge= function(request) {
   if (401 == request.statusCode && 'www-authenticate' in request.headers) {
     if (!this.parse_header) {
-      this.parse_header= www_authenticator(this.credentials,this.options)
+      this.parse_header= www_authenticator(this.credentials,this.options);
     }
-    this.challenge= this.parse_header(request.headers['www-authenticate'])
+    this.challenge= this.parse_header(request.headers['www-authenticate']);
     return this.challenge.err;
   }
-}
+};
 HigherLevel.prototype._challenge= function() {
   if (!this.challenge) {
     if (this.sendImmediately) {
       // simulate receipt of a basic challenge
-      this.get_challenge(basic_challenge)
-      return this.challenge
+      this.get_challenge(basic_challenge);
+      return this.challenge;
     }
-    else return;   // simply won't produce an 'Authorization' header
+    else {return;}   // simply won't produce an 'Authorization' header
   }
   return this.challenge;
-}
+};
 HigherLevel.prototype.authentication_string= function(method,digestURI) {
-  var challenge= this._challenge();
-  if (!challenge) return;   // simply won't produce an 'Authorization' header
-  if (challenge.err) return challenge.err;
+  const challenge= this._challenge();
+  if (!challenge) {return;}   // simply won't produce an 'Authorization' header
+  if (challenge.err) {return challenge.err;}
   return challenge.authorize(method,digestURI);
-}
+};
 HigherLevel.prototype.authenticate_headers= function(headers,method,digestURI) {
-  var challenge= this._challenge();
-  if (!challenge) return;   // simply won't produce an 'Authorization' header
-  if (challenge.err) return challenge.err;
+  const challenge= this._challenge();
+  if (!challenge) {return;}   // simply won't produce an 'Authorization' header
+  if (challenge.err) {return challenge.err;}
   headers.authorization= challenge.authorize(method,digestURI);
-}
+};
 HigherLevel.prototype.authenticate_request_options= function(request_options) {
-  var challenge= this._challenge();
-  if (!challenge) return;   // simply won't produce an 'Authorization' header
-  if (challenge.err) return challenge.err;
-  if (!request_options.headers) request_options.headers= {};
+  const challenge= this._challenge();
+  if (!challenge) {return;}   // simply won't produce an 'Authorization' header
+  if (challenge.err) {return challenge.err;}
+  if (!request_options.headers) {request_options.headers= {};}
   request_options.headers.authorization= challenge.authorize(request_options.method,request_options.path);
-}
+};
 
 module.exports = www_authenticator;
 module.exports.parsers= parsers;
@@ -198,6 +198,6 @@ module.exports.authenticator= function(username,password,options)
     options= password;
     password= null;
   }
-  var credentials= user_credentials(username,password)
+  const credentials= user_credentials(username,password);
   return new HigherLevel(credentials,options);
-}
\ No newline at end of file
+};
\ No newline at end of file