feat(server): made startUnixSocket take one callback

Author: knagaitsev

lib/Server.js

@@ -752,20 +752,16 @@ class Server {
       }
     };
 
-    const listenCallback = () => {
+    const onListeningCallback = () => {
       if (typeof this.options.onListening === 'function') {
         this.options.onListening(this);
       }
     };
 
-    const setupAndListenCallback = () => {
-      setupCallback();
-      listenCallback();
-    };
-
     const fullCallback = (err) => {
-      setupAndListenCallback();
+      setupCallback();
       userCallback(err);
+      onListeningCallback();
     };
 
     // try to follow the Node standard in terms of deciding
@@ -777,12 +773,7 @@ class Server {
       // set this so that status helper can identify how the project is being run correctly
       this.options.socket = socket;
 
-      startUnixSocket(
-        this.listeningApp,
-        socket,
-        setupAndListenCallback,
-        userCallback
-      );
+      startUnixSocket(this.listeningApp, socket, fullCallback);
     } else {
       this.listeningApp.listen(port, hostname, fullCallback);
     }

lib/utils/startUnixSocket.js

@@ -3,20 +3,7 @@
 const fs = require('fs');
 const net = require('net');
 
-// userCallback should always be called to indicate that either the server has
-// started listening, or an error was thrown.
-// setupAndListenCallback should only be called if the server starts listening
-function startUnixSocket(
-  listeningApp,
-  socket,
-  setupAndListenCallback,
-  userCallback
-) {
-  const fullCallback = (err) => {
-    setupAndListenCallback();
-    userCallback(err);
-  };
-
+function startUnixSocket(listeningApp, socket, cb) {
   const chmodSocket = (done) => {
     // chmod 666 (rw rw rw) - octal
     const READ_WRITE = 438;
@@ -25,16 +12,16 @@ function startUnixSocket(
 
   const startSocket = () => {
     listeningApp.on('error', (err) => {
-      userCallback(err);
+      cb(err);
     });
 
     // 511 is the default value for the server.listen backlog parameter
     // https://nodejs.org/api/net.html#net_server_listen
     listeningApp.listen(socket, 511, (err) => {
       if (err) {
-        fullCallback(err);
+        cb(err);
       } else {
-        chmodSocket(fullCallback);
+        chmodSocket(cb);
       }
     });
   };
@@ -62,9 +49,7 @@ function startUnixSocket(
         // it means that the socket is in use
         const err = new Error('This socket is already used');
         clientSocket.destroy();
-        // do not call onListening or the setup method, since the server
-        // cannot start listening on a used socket
-        userCallback(err);
+        cb(err);
       });
     }
   });

test/server/utils/startUnixSocket.test.js

@@ -15,15 +15,10 @@ describe('startUnixSocket', () => {
     let err;
     beforeAll((done) => {
       testUnixSocket = new TestUnixSocket();
-      startUnixSocket(
-        testUnixSocket.server,
-        socketPath,
-        () => {},
-        (e) => {
-          err = e;
-          done();
-        }
-      );
+      startUnixSocket(testUnixSocket.server, socketPath, (e) => {
+        err = e;
+        done();
+      });
     });
 
     it('should work as Unix socket or error on windows', (done) => {
@@ -55,7 +50,7 @@ describe('startUnixSocket', () => {
     beforeAll((done) => {
       fs.writeFileSync(socketPath, '');
       testUnixSocket = new TestUnixSocket();
-      startUnixSocket(testUnixSocket.server, socketPath, () => {}, done);
+      startUnixSocket(testUnixSocket.server, socketPath, done);
     });
 
     it('should work as Unix socket', (done) => {
@@ -89,17 +84,12 @@ describe('startUnixSocket', () => {
 
     it('should throw already used error', (done) => {
       testUnixSocket = new TestUnixSocket();
-      startUnixSocket(
-        testUnixSocket.server,
-        socketPath,
-        () => {},
-        (err) => {
-          expect(err).not.toBeNull();
-          expect(err).not.toBeUndefined();
-          expect(err.message).toEqual('This socket is already used');
-          testUnixSocket.close(done);
-        }
-      );
+      startUnixSocket(testUnixSocket.server, socketPath, (err) => {
+        expect(err).not.toBeNull();
+        expect(err).not.toBeUndefined();
+        expect(err.message).toEqual('This socket is already used');
+        testUnixSocket.close(done);
+      });
     });
 
     afterAll((done) => {
@@ -120,12 +110,7 @@ describe('startUnixSocket', () => {
     // could be removed
     it('should only call server.listen callback once', (done) => {
       const userCallback = jest.fn();
-      startUnixSocket(
-        testUnixSocket.server,
-        socketPath,
-        () => {},
-        userCallback
-      );
+      startUnixSocket(testUnixSocket.server, socketPath, userCallback);
       setTimeout(() => {
         expect(userCallback).toBeCalledTimes(1);
         done();