addresses #998 to properly assign a random port and access the port assigned (#1054)

Author: shellscape

bin/webpack-dev-server.js

@@ -337,6 +337,7 @@ function processOptions(webpackOptions) {
   // were specified, but since argv.port is 8080, options.port will be
   // tried first instead.
   options.port = argv.port === DEFAULT_PORT ? defaultTo(options.port, argv.port) : defaultTo(argv.port, options.port);
+
   if (options.port != null) {
     startDevServer(wpOpt, options);
     return;
@@ -370,7 +371,7 @@ function startDevServer(webpackOptions, options) {
     }));
   }
 
-  const uri = createDomain(options) + (options.inline !== false || options.lazy === true ? '/' : '/webpack-dev-server/');
+  const suffix = (options.inline !== false || options.lazy === true ? '/' : '/webpack-dev-server/');
 
   let server;
   try {
@@ -415,13 +416,17 @@ function startDevServer(webpackOptions, options) {
       const READ_WRITE = 438;
       fs.chmod(options.socket, READ_WRITE, (fsError) => {
         if (fsError) throw fsError;
+
+        const uri = createDomain(options, server.listeningApp) + suffix;
         reportReadiness(uri, options);
       });
     });
   } else {
     server.listen(options.port, options.host, (err) => {
       if (err) throw err;
       if (options.bonjour) broadcastZeroconf(options);
+
+      const uri = createDomain(options, server.listeningApp) + suffix;
       reportReadiness(uri, options);
     });
   }

lib/util/createDomain.js

@@ -3,13 +3,17 @@
 const url = require('url');
 const internalIp = require('internal-ip');
 
-module.exports = function createDomain(options) {
+
+module.exports = function createDomain(options, listeningApp) {
   const protocol = options.https ? 'https' : 'http';
+  const appPort = listeningApp ? listeningApp.address().port : 0;
+  const port = options.socket ? 0 : appPort;
+  const hostname = options.useLocalIp ? internalIp.v4() : options.host;
 
   // the formatted domain (url without path) of the webpack server
   return options.public ? `${protocol}://${options.public}` : url.format({
     protocol,
-    hostname: options.useLocalIp ? internalIp.v4() : options.host,
-    port: options.socket ? 0 : options.port.toString()
+    hostname,
+    port
   });
 };