Merge pull request #1284 from ethereum/remixderror2

libs/remixd/src/bin/remixd.ts

@@ -36,12 +36,21 @@ const ports = {
 }
 
 const killCallBack: Array<Function> = []
-function startService<S extends 'git' | 'hardhat' | 'folder'> (service: S, callback: (ws: WS, sharedFolderClient: servicesList.Sharedfolder) => void) {
+function startService<S extends 'git' | 'hardhat' | 'folder'> (service: S, callback: (ws: WS, sharedFolderClient: servicesList.Sharedfolder, error?:Error) => void) {
   const socket = new WebSocket(ports[service], { remixIdeUrl: program.remixIde }, () => services[service](program.readOnly || false))
   socket.start(callback)
   killCallBack.push(socket.close.bind(socket))
 }
 
+function errorHandler (error: any, service: string) {
+  const port = ports[service]
+  if (error.code && error.code === 'EADDRINUSE') {
+    console.log('\x1b[31m%s\x1b[0m', `[ERR] There is already a client running on port ${port}!`)
+  } else {
+    console.log('\x1b[31m%s\x1b[0m', '[ERR]', error)
+  }
+}
+
 (async () => {
   const { version } = require('../package.json')
   program.version(version, '-v, --version')
@@ -76,7 +85,11 @@ function startService<S extends 'git' | 'hardhat' | 'folder'> (service: S, callb
     console.log('\x1b[33m%s\x1b[0m', '[WARN] Any application that runs on your computer can potentially read from and write to all files in the directory.')
     console.log('\x1b[33m%s\x1b[0m', '[WARN] Symbolic links are not forwarded to Remix IDE\n')
     try {
-      startService('folder', (ws: WS, sharedFolderClient: servicesList.Sharedfolder) => {
+      startService('folder', (ws: WS, sharedFolderClient: servicesList.Sharedfolder, error: any) => {
+        if (error) {
+          errorHandler(error, 'hardhat')
+          return false
+        }
         sharedFolderClient.setWebSocket(ws)
         sharedFolderClient.setupNotifications(program.sharedFolder)
         sharedFolderClient.sharedFolder(program.sharedFolder)
@@ -85,7 +98,11 @@ function startService<S extends 'git' | 'hardhat' | 'folder'> (service: S, callb
       const hardhatConfigFilePath = absolutePath('./', program.sharedFolder) + '/hardhat.config.js'
       const isHardhatProject = fs.existsSync(hardhatConfigFilePath)
       if (isHardhatProject) {
-        startService('hardhat', (ws: WS, sharedFolderClient: servicesList.Sharedfolder) => {
+        startService('hardhat', (ws: WS, sharedFolderClient: servicesList.Sharedfolder, error: Error) => {
+          if (error) {
+            errorHandler(error, 'hardhat')
+            return false
+          }
           sharedFolderClient.setWebSocket(ws)
           sharedFolderClient.sharedFolder(program.sharedFolder)
         })

libs/remixd/src/websocket.ts

@@ -9,7 +9,7 @@ export default class WebSocket {
 
   constructor (public port: number, public opt: WebsocketOpt, public getclient: () => ServiceClient) {} //eslint-disable-line
 
-  start (callback?: (ws: WS, client: ServiceClient) => void): void {
+  start (callback?: (ws: WS, client: ServiceClient, error?: Error) => void): void {
     this.server = http.createServer((request, response) => {
       console.log((new Date()) + ' Received request for ' + request.url)
       response.writeHead(404)
@@ -21,9 +21,15 @@ export default class WebSocket {
       65521: 'git',
       65522: 'hardhat'
     }
+
+    this.server.on('error', (error: Error) => {
+      if (callback)callback(null, null, error)
+    })
+
     this.server.listen(this.port, loopback, () => {
       console.log('\x1b[32m%s\x1b[0m', `[INFO] ${new Date()} ${listeners[this.port]} is listening on ${loopback}:${this.port}`)
     })
+
     this.wsServer = new WS.Server({
       server: this.server,
       verifyClient: (info, done) => {