LOG-16581 Fix winston JSON logging (#21)

Author: sbialkowski-r7

.eslintrc

@@ -1,6 +1,9 @@
 {
   "env": { "es6": true, "node": true },
   "extends": "rapid7/node",
+  "parserOptions": {
+    "ecmaVersion": 2018
+  },
   "rules": {
     "comma-dangle": 0,
     "prefer-rest-params": 0,

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "r7insight_node",
-  "version": "2.1.1",
+  "version": "3.0.0",
   "description": "Rapid7 Insight Platform client for node; use with or without Winston or Bunyan.",
   "keywords": [
     "logentries",

package.json

@@ -1,7 +1,7 @@
 const _ = require('lodash');
-const stringify = require('json-stringify-safe');
 
 const Logger = require('./logger');
+const stringify = require('json-stringify-safe');
 
 /**
  * Generate the InsightTransport Winston Transport.  
@@ -29,7 +29,7 @@ function generateTransport(winston, winstonTransport) {
     */
     constructor(opts) {
       super(opts);
-      this.json = opts.json || false;
+      this.json = !!opts.json;
 
       const transportOpts = _.clone(opts || {});
 
@@ -65,21 +65,47 @@ function generateTransport(winston, winstonTransport) {
      * @returns {void}
     */
     log(info) {
-      //  If we have specified to log in JSON format, then stringify
-      //
-      //  Also, if the `info` object which is passed from winston has more
-      //  that 2 default keys (`message` and `level`), then that means that
-      //  the `log` function was called with more two than keys
-      //  (referred to as metadata), so in that scenario we stringify the
-      //  entire message since it is not obvious what format the user wants.
+      //  This function is required since Winston passes in metadata in a strange way.
+      //  Rather than giving us a complete object containing all metadata, it hides it away
+      //  in the splat attribute and passes in only the first piece of metadata
       //  
-      //  log function, without being given a log (like below) will just log
-      //  the level, which in this case is our message.
-      if (this.json || Object.keys(info).length > 2) {
-        this.logger.log(stringify(info));
+      //  This seems to be an existing issue faced by devs:
+      //  https://stackoverflow.com/a/60866937
+      const returnMetadata = (meta) => {
+        // You can format the splat yourself
+        const splat = meta[Symbol.for('splat')];
+
+        if (splat && splat.length) {
+          return splat.reduce((result, current) => ({
+            ...result,
+            ...current
+          }), {});
+        }
+
+        return {};
+      };
+
+      const metadata = returnMetadata(info);
+
+      if (this.json) {
+        //  If we are to output JSON, we create the full object containing level, message and metadata.
+        //
+        //  We don't serialize here but pass in an object since InsightLogger appends extra keys based on
+        //  configuration, e.g. timestamp before serializing to JSON
+        //
+        //  We also don't specify the first argument of `level` since the winston `info` contains it.
+        //  If we did provide it InsightLogger would append an extra redundant `_level` key.
+        this.logger.log({
+          ...info,
+          ...metadata,
+        });
+      } else if (Object.keys(info).length > 2) {
+        //  If we are not outputting to JSON and have metadata, we use the same format as Winston
+        const message = `${info.level}: ${info.message} ${stringify(metadata)}`;
+
+        this.logger.log(message);
       } else {
-        //  If we do get the default keys of `level` and `message` then we
-        //  can use the default format of `<level> <message>`
+        //  If we're not outputting JSON, nor have metadata, we produce a simple message
         this.logger.log(info.level, info.message);
       }
     }