feat: report package identity in requests/responses

Author: mikuso

lib/client.js

@@ -5,7 +5,7 @@ const WebSocket = require('ws');
 const { ExponentialStrategy } = require('backoff');
 const {CONNECTING, OPEN, CLOSING, CLOSED} = WebSocket;
 const { TimeoutError, UnexpectedHttpResponse, RPCFrameworkError, RPCGenericError, RPCMessageTypeNotSupportedError } = require('./errors');
-const { getErrorPlainObject, createRPCError } = require('./util');
+const { getErrorPlainObject, createRPCError, getPackageIdent } = require('./util');
 const Queue = require('./queue');
 const EventBuffer = require('./event-buffer');
 const standardValidators = require('./standard-validators');
@@ -411,7 +411,9 @@ class RPCClient extends EventEmitter {
                 // defaults
                 noDelay: true,
                 signal: this._wsAbortController.signal,
-                headers: {},
+                headers: {
+                    'user-agent': getPackageIdent()
+                },
             }, this._options.wsOpts ?? {});
 
             Object.assign(wsOpts.headers, this._options.headers);

lib/server.js

@@ -4,6 +4,7 @@ const {createServer} = require('http');
 const RPCServerClient = require('./server-client');
 const { abortHandshake, parseSubprotocols } = require('./ws-util');
 const standardValidators = require('./standard-validators');
+const { getPackageIdent } = require('./util');
 
 class RPCServer extends EventEmitter {
     constructor(options) {
@@ -38,6 +39,7 @@ class RPCServer extends EventEmitter {
             },
         });
 
+        this._wss.on('headers', h => h.push(`Server: ${getPackageIdent()}`));
         this._wss.on('error', err => this.emit('error', err));
         this._wss.on('connection', this._onConnection.bind(this));
     }
@@ -223,6 +225,7 @@ class RPCServer extends EventEmitter {
         const httpServer = createServer({
             noDelay: true,
         }, (req, res) => {
+            res.setHeader('Server', getPackageIdent());
             res.statusCode = 404;
             res.end();
         });

lib/util.js

@@ -1,4 +1,5 @@
 const errors = require('./errors');
+const package = require('../package.json');
 
 const rpcErrorLUT = {
     'GenericError'                  : errors.RPCGenericError,
@@ -17,6 +18,10 @@ const rpcErrorLUT = {
     'RpcFrameworkError'             : errors.RPCFrameworkError,
 };
 
+function getPackageIdent() {
+    return `${package.name}/${package.version} (${process.platform})`;
+}
+
 function getErrorPlainObject(err) {
     try {
 
@@ -44,4 +49,5 @@ function createRPCError(type, message, details) {
 module.exports = {
     getErrorPlainObject,
     createRPCError,
+    getPackageIdent,
 };