[react-packager] Make sure server is listening on socket

react-packager/src/SocketInterface/__tests__/SocketInterface-test.js

@@ -26,6 +26,17 @@ describe('SocketInterface', () => {
     pit('creates socket path by hashing options', () => {
       const fs = require('fs');
       fs.existsSync = jest.genMockFn().mockImpl(() => true);
+      fs.unlinkSync = jest.genMockFn();
+      let callback;
+
+      require('child_process').spawn.mockImpl(() => ({
+        on: (event, cb) => callback = cb,
+        send: (message) => {
+          setImmediate(() => callback({ type: 'createdServer' }));
+        },
+        unref: () => undefined,
+        disconnect: () => undefined,
+      }));
 
       // Check that given two equivelant server options, we end up with the same
       // socket path.
@@ -49,6 +60,7 @@ describe('SocketInterface', () => {
     pit('should fork a server', () => {
       const fs = require('fs');
       fs.existsSync = jest.genMockFn().mockImpl(() => false);
+      fs.unlinkSync = jest.genMockFn();
       let sockPath;
       let callback;
 

react-packager/src/SocketInterface/index.js

@@ -14,6 +14,7 @@ const SocketServer = require('./SocketServer');
 const _ = require('underscore');
 const crypto = require('crypto');
 const fs = require('fs');
+const net = require('net');
 const path = require('path');
 const tmpdir = require('os').tmpdir();
 const {spawn} = require('child_process');
@@ -38,10 +39,27 @@ const SocketInterface = {
       );
 
       if (fs.existsSync(sockPath)) {
+        var sock = net.connect(sockPath);
+        sock.on('connect', () => {
+          sock.end();
           resolve(SocketClient.create(sockPath));
-        return;
+        });
+        sock.on('error', (e) => {
+          fs.unlinkSync(sockPath);
+          createServer(resolve, reject, options, sockPath);
+        });
+      } else {
+        createServer(resolve, reject, options, sockPath);
       }
+    });
+  },
 
+  listenOnServerMessages() {
+    return SocketServer.listenOnServerIPCMessages();
+  }
+};
+
+function createServer(resolve, reject, options, sockPath) {
   const logPath = path.join(tmpdir, 'react-packager.log');
 
   const timeout = setTimeout(
@@ -78,11 +96,11 @@ const SocketInterface = {
     if (m && m.type && m.type === 'createdServer') {
       clearTimeout(timeout);
       child.disconnect();
+
       resolve(SocketClient.create(sockPath));
     }
   });
 
-
   if (options.blacklistRE) {
     options.blacklistRE = { source: options.blacklistRE.source };
   }
@@ -91,13 +109,6 @@ const SocketInterface = {
     type: 'createSocketServer',
     data: { sockPath, options }
   });
-    });
-  },
-
-  listenOnServerMessages() {
-    return SocketServer.listenOnServerIPCMessages();
-  }
-
-};
+}
 
 module.exports = SocketInterface;