Extracting channel module

Author: bigmontz

packages/testkit-backend/src/backend.js

@@ -1,34 +1,42 @@
-import SocketServer from './socket.server'
+import Channel from './channel'
 import Controller from './controller'
 
+/**
+ * Binds Channel and Controller
+ */
 export default class Backend {
-  constructor (port, newController = () => new Controller(), newSocketServer = port => new SocketServer(port)) {
-    this._socketServer = newSocketServer(port)
+  /**
+   *
+   * @param {function():Controller} newController The controller factory function
+   * @param {function():Channel} newChannel The channel factory function
+   */
+  constructor (newController, newChannel) {
+    this._channel = newChannel()
     this._controller = newController()
 
     this._controller.on('response', ({ contextId, response }) => {
-      this._socketServer.writeResponse(contextId, response)
+      this._channel.writeResponse(contextId, response)
     })
 
-    this._socketServer.on('contextOpen', ({ contextId }) => this._controller.onContextOpen(contextId))
-    this._socketServer.on('contextClose', ({ contextId }) => this._controller.onContextClose(contextId))
+    this._channel.on('contextOpen', ({ contextId }) => this._controller.onContextOpen(contextId))
+    this._channel.on('contextClose', ({ contextId }) => this._controller.onContextClose(contextId))
 
-    this._socketServer.on('request', ({ contextId, request }) => { 
+    this._channel.on('request', ({ contextId, request }) => {
       try {
         this._controller.handle(contextId, request)
       } catch (e) {
-        this._socketServer.writeBackendError(contextId, e)
+        this._channel.writeBackendError(contextId, e)
       }
     })
   }
 
   start () {
     this._controller.start()
-    this._socketServer.start()
+    this._channel.start()
   }
 
   stop () {
-    this._socketServer.stop()
+    this._channel.stop()
     this._controller.stop()
   }
 

packages/testkit-backend/src/channel/abstract.js

@@ -0,0 +1,21 @@
+import { EventEmitter } from "events"
+
+export default class Channel extends EventEmitter {
+
+  start () {
+    throw Error('Not implemented')
+  }
+
+  stop () {
+    throw Error('Not implemented')
+  }
+
+  writeResponse (contextId, response) {
+    throw Error('Not implemented')
+  }
+
+  writeBackendError (contextId, error) {
+    this.writeResponse(contextId, { name: 'BackendError', data:  { msg: error } })
+  }
+
+}

packages/testkit-backend/src/channel/index.js

@@ -0,0 +1,7 @@
+import Channel from "./abstract"
+import SocketChannel from "./socket"
+
+export default Channel
+export {
+  SocketChannel
+}

packages/testkit-backend/src/socket.server.js renamed to packages/testkit-backend/src/channel/socket.js

@@ -1,7 +1,7 @@
 import { EventEmitter } from 'events'
 import net from 'net'
 import { randomBytes } from 'crypto'
-import Protocol from './protocol'
+import Protocol from './testkit-protocol'
 
 function generateRandomId () {
   return randomBytes(16).toString()
@@ -42,7 +42,7 @@ export default class SocketServer extends EventEmitter {
 
     this.emit('contextOpen', { contextId })
     protocol.on('request', request => this.emit('request', { contextId, request }) )
-    protocol.on('error', e => this.writeBackendError(contextId, e))
+    protocol.on('error', e => this._writeBackendError(contextId, e))
 
     connection.on('end', () =>  { 
       if (this._clients.has(contextId)) {

packages/testkit-backend/src/protocol.js renamed to packages/testkit-backend/src/channel/testkit-protocol.js

@@ -1,8 +1,11 @@
 import Backend from './backend'
+import { SocketChannel } from './channel'
 import NodeController from './node.controller'
 
 function main( ) {
-  const backend = new Backend(process.env.BACKEND_PORT || 9876, () => new NodeController())
+  const newChannel = () => new SocketChannel(process.env.BACKEND_PORT || 9876)
+  const newController = () => new NodeController()
+  const backend = new Backend(newController, newChannel)
 
   backend.start()
 
@@ -16,4 +19,4 @@ function main( ) {
   process.on('uncaughtException', process.exit.bind(process));
 }
 
-main()
+main()