feat(ui): improved IpcMessenger with new options

docs/dev-guide/ui-api.md

@@ -949,9 +949,6 @@ const { IpcMessenger } = require('@vue/cli-shared-utils')
 // Create a new IpcMessenger instance
 const ipc = new IpcMessenger()
 
-// Connect to the vue-cli IPC network
-ipc.connect()
-
 function sendMessage (data) {
   // Send a message to the cli-ui server
   ipc.send({
@@ -978,6 +975,42 @@ function cleanup () {
 }
 ```
 
+Manual connection:
+
+```js
+const ipc = new IpcMessenger({
+  autoConnect: false
+})
+
+// This message will be queued
+ipc.send({ ... })
+
+ipc.connect()
+```
+
+Auto disconnect on idle (after some time without sending any message):
+
+```js
+const ipc = new IpcMessenger({
+  disconnectOnIdle: true,
+  idleTimeout: 3000 // Default
+})
+
+ipc.send({ ... })
+
+setTimeout(() => {
+  console.log(ipc.connected) // false
+}, 3000)
+```
+
+Connect to another IPC network:
+
+```js
+const ipc = new IpcMessenger({
+  networkId: 'my-ipc-network'
+})
+```
+
 In a vue-cli plugin `ui.js` file, you can use the `ipcOn`, `ipcOff` and `ipcSend` methods:
 
 ```js

packages/@vue/cli-service/lib/commands/serve.js

@@ -209,7 +209,6 @@ module.exports = (api, options) => {
           // Send final app URL
           if (args.dashboard) {
             const ipc = new IpcMessenger()
-            ipc.connect()
             ipc.send({
               vueServe: {
                 url: urls.localUrlForBrowser

packages/@vue/cli-service/lib/webpack/DashboardPlugin.js

@@ -52,7 +52,6 @@ class DashboardPlugin {
     let assetSources = new Map()
 
     if (!sendData) {
-      ipc.connect()
       sendData = data => ipc.send({
         webpackDashboardData: {
           type: this.type,

packages/@vue/cli-shared-utils/lib/ipc.js

@@ -1,10 +1,18 @@
 const ipc = require('node-ipc')
 
-const defaultId = process.env.VUE_CLI_IPC || 'vue-cli'
+const DEFAULT_ID = process.env.VUE_CLI_IPC || 'vue-cli'
+const DEFAULT_IDLE_TIMEOUT = 3000
+const DEFAULT_OPTIONS = {
+  networkId: DEFAULT_ID,
+  autoConnect: true,
+  disconnectOnIdle: false,
+  idleTimeout: DEFAULT_IDLE_TIMEOUT
+}
 
 exports.IpcMessenger = class IpcMessenger {
-  constructor (id = defaultId) {
-    ipc.config.id = this.id = id
+  constructor (options = {}) {
+    options = Object.assign({}, DEFAULT_OPTIONS, options)
+    ipc.config.id = this.id = options.networkId
     ipc.config.retry = 1500
     ipc.config.silent = true
 
@@ -12,10 +20,12 @@ exports.IpcMessenger = class IpcMessenger {
     this.connecting = false
     this.disconnecting = false
     this.queue = null
+    this.options = options
 
     this.listeners = []
 
     this.disconnectTimeout = 15000
+    this.idleTimer = null
 
     // Prevent forced process exit
     // (or else ipc messages may not be sent before kill)
@@ -29,8 +39,18 @@ exports.IpcMessenger = class IpcMessenger {
   send (data, type = 'message') {
     if (this.connected) {
       ipc.of[this.id].emit(type, data)
+
+      clearTimeout(this.idleTimer)
+      if (this.options.disconnectOnIdle) {
+        this.idleTimer = setTimeout(() => {
+          this.disconnect()
+        }, this.options.idleTimeout)
+      }
     } else {
       this.queue.push(data)
+      if (this.options.autoConnect && !this.connecting) {
+        this.connect()
+      }
     }
   }