Allow to attach the HMR server to an external http server

Reviewed By: BYK

Differential Revision: D6752279

fbshipit-source-id: 250255a3b1226f8aab6054e507cb3910cdcd6a85

packages/metro/src/HmrServer/__tests__/HmrServer-test.js

@@ -17,7 +17,6 @@ const {EventEmitter} = require('events');
 
 describe('HmrServer', () => {
   let hmrServer;
-  let reporterMock;
   let serverMock;
   let deltaBundlerMock;
   let deltaTransformerMock;
@@ -41,12 +40,14 @@ describe('HmrServer', () => {
       getDeltaBundler() {
         return deltaBundlerMock;
       },
-    };
-    reporterMock = {
-      update: jest.fn(),
+      getReporter() {
+        return {
+          update: jest.fn(),
+        };
+      },
     };
 
-    hmrServer = new HmrServer(serverMock, reporterMock);
+    hmrServer = new HmrServer(serverMock);
   });
 
   it('should pass the correct options to the delta bundler', async () => {

packages/metro/src/HmrServer/index.js

@@ -44,9 +44,9 @@ class HmrServer<TClient: Client> {
   _packagerServer: PackagerServer;
   _reporter: Reporter;
 
-  constructor(packagerServer: PackagerServer, reporter: Reporter) {
+  constructor(packagerServer: PackagerServer) {
     this._packagerServer = packagerServer;
-    this._reporter = reporter;
+    this._reporter = packagerServer.getReporter();
   }
 
   async onClientConnect(

packages/metro/src/Server/index.js

@@ -865,6 +865,10 @@ class Server {
     return (this._nextBundleBuildID++).toString(36);
   }
 
+  getReporter(): Reporter {
+    return this._reporter;
+  }
+
   static DEFAULT_BUNDLE_OPTIONS = {
     assetPlugins: [],
     dev: true,

packages/metro/src/index.js

@@ -166,6 +166,13 @@ exports.createConnectMiddleware = async function(
     : Config.DEFAULT;
 
   return {
+    attachHmrServer(httpServer: HttpServer | HttpsServer) {
+      attachWebsocketServer({
+        httpServer,
+        path: '/hot',
+        websocketServer: new MetroHmrServer(metroServer),
+      });
+    },
     metroServer,
     middleware: normalizedConfig.enhanceMiddleware(metroServer.processRequest),
     end() {
@@ -195,7 +202,11 @@ exports.runServer = async (options: RunServerOptions) => {
 
   const serverApp = connect();
 
-  const {metroServer, middleware, end} = await exports.createConnectMiddleware({
+  const {
+    attachHmrServer,
+    middleware,
+    end,
+  } = await exports.createConnectMiddleware({
     config: options.config,
     maxWorkers: options.maxWorkers,
     port,
@@ -221,11 +232,7 @@ exports.runServer = async (options: RunServerOptions) => {
   }
 
   if (options.hmrEnabled) {
-    attachWebsocketServer({
-      httpServer,
-      path: '/hot',
-      websocketServer: new MetroHmrServer(metroServer, reporter),
-    });
+    attachHmrServer(httpServer);
   }
 
   httpServer.listen(port, options.host, () => {