feat(serve): implement open browser option

Closes angular#1081

Author: dzonatan

packages/angular-cli/commands/serve.ts

@@ -26,6 +26,7 @@ export interface ServeTaskOptions {
   sslKey?: string;
   sslCert?: string;
   aot?: boolean;
+  open?: boolean;
 }
 
 const ServeCommand = Command.extend({
@@ -79,7 +80,13 @@ const ServeCommand = Command.extend({
     { name: 'ssl',                  type: Boolean, default: false },
     { name: 'ssl-key',              type: String,  default: 'ssl/server.key' },
     { name: 'ssl-cert',             type: String,  default: 'ssl/server.crt' },
-    { name: 'aot',                  type: Boolean, default: false }
+    { name: 'aot',                  type: Boolean, default: false },
+    { 
+      name: 'open',
+      description: 'Opens the url in default browser',
+      type: Boolean, 
+      default: false 
+    },
   ],
 
   run: function(commandOptions: ServeTaskOptions) {

packages/angular-cli/tasks/serve-webpack.ts

@@ -11,6 +11,7 @@ import { NgCliWebpackConfig } from '../models/webpack-config';
 import { ServeTaskOptions } from '../commands/serve';
 import { CliConfig } from '../models/config';
 import { oneLine } from 'common-tags';
+const opn = require('opn');
 
 export default Task.extend({
   run: function(commandOptions: ServeTaskOptions) {
@@ -78,6 +79,10 @@ export default Task.extend({
           console.error(err.stack || err);
           if (err.details) { console.error(err.details); }
           reject(err.details);
+        } else {
+          if(commandOptions.open) {
+            opn(`http://${commandOptions.host}:${commandOptions.port}/`); 
+          }
         }
       });
     });