From 61d0cdf62c539cef9ad8e250b09571875fd14e87 Mon Sep 17 00:00:00 2001
From: Evilebot Tnawi <evilebottnawi@users.noreply.github.com>
Date: Wed, 29 May 2019 23:25:37 +0300
Subject: [PATCH] feat: `onListening` option (#1930)

---
 lib/Server.js                                |  8 ++++++
 lib/options.json                             |  4 +++
 test/CreateConfig.test.js                    | 12 ++++++++
 test/__snapshots__/CreateConfig.test.js.snap | 15 ++++++++++
 test/onListening.test.js                     | 30 ++++++++++++++++++++
 test/options.test.js                         |  4 +++
 6 files changed, 73 insertions(+)
 create mode 100644 test/onListening.test.js

diff --git a/lib/Server.js b/lib/Server.js
index 70ab40b747..01173d119c 100644
--- a/lib/Server.js
+++ b/lib/Server.js
@@ -414,6 +414,8 @@ class Server {
   }
 
   setupBeforeFeature() {
+    // Todo rename onBeforeSetupMiddleware in next major release
+    // Todo pass only `this` argument
     this.options.before(this.app, this, this.compiler);
   }
 
@@ -422,6 +424,8 @@ class Server {
   }
 
   setupAfterFeature() {
+    // Todo rename onAfterSetupMiddleware in next major release
+    // Todo pass only `this` argument
     this.options.after(this.app, this, this.compiler);
   }
 
@@ -722,6 +726,10 @@ class Server {
       if (fn) {
         fn.call(this.listeningApp, err);
       }
+
+      if (typeof this.options.onListening === 'function') {
+        this.options.onListening(this);
+      }
     });
   }
 
diff --git a/lib/options.json b/lib/options.json
index 89b125b7ff..c42e0ffcc6 100644
--- a/lib/options.json
+++ b/lib/options.json
@@ -195,6 +195,9 @@
     "noInfo": {
       "type": "boolean"
     },
+    "onListening": {
+      "instanceof": "Function"
+    },
     "open": {
       "anyOf": [
         {
@@ -402,6 +405,7 @@
       "logTime": "should be {Boolean} (https://github.com/webpack/webpack-dev-middleware#logtime)",
       "mimeTypes": "should be {Object} (https://webpack.js.org/configuration/dev-server/#devservermimetypes-)",
       "noInfo": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devservernoinfo-)",
+      "onListening": "should be {Function} (https://webpack.js.org/configuration/dev-server/#onlistening)",
       "open": "should be {String|Boolean} (https://webpack.js.org/configuration/dev-server/#devserveropen)",
       "openPage": "should be {String} (https://webpack.js.org/configuration/dev-server/#devserveropenpage)",
       "overlay": "should be {Boolean|Object} (https://webpack.js.org/configuration/dev-server/#devserveroverlay)",
diff --git a/test/CreateConfig.test.js b/test/CreateConfig.test.js
index 97c5d47cba..3c00c90dd1 100644
--- a/test/CreateConfig.test.js
+++ b/test/CreateConfig.test.js
@@ -967,4 +967,16 @@ describe('createConfig', () => {
     ).toMatchSnapshot();
     expect(webpackConfigNoStats).toMatchSnapshot();
   });
+
+  it('onListening option', () => {
+    const config = createConfig(
+      Object.assign({}, webpackConfig, {
+        devServer: { onListening: () => {} },
+      }),
+      argv,
+      { port: 8080 }
+    );
+
+    expect(config).toMatchSnapshot();
+  });
 });
diff --git a/test/__snapshots__/CreateConfig.test.js.snap b/test/__snapshots__/CreateConfig.test.js.snap
index a3ec18de9c..8cf61a8f6d 100644
--- a/test/__snapshots__/CreateConfig.test.js.snap
+++ b/test/__snapshots__/CreateConfig.test.js.snap
@@ -740,6 +740,21 @@ Object {
 }
 `;
 
+exports[`createConfig onListening option 1`] = `
+Object {
+  "hot": true,
+  "hotOnly": false,
+  "noInfo": true,
+  "onListening": [Function],
+  "port": 8080,
+  "publicPath": "/",
+  "stats": Object {
+    "cached": false,
+    "cachedAssets": false,
+  },
+}
+`;
+
 exports[`createConfig open option (boolean) (in devServer config) 1`] = `
 Object {
   "hot": true,
diff --git a/test/onListening.test.js b/test/onListening.test.js
new file mode 100644
index 0000000000..249507aca5
--- /dev/null
+++ b/test/onListening.test.js
@@ -0,0 +1,30 @@
+'use strict';
+
+const testServer = require('./helpers/test-server');
+const config = require('./fixtures/simple-config/webpack.config');
+
+describe('Before And After options', () => {
+  let onListeningIsRunning = false;
+
+  beforeAll((done) => {
+    testServer.start(
+      config,
+      {
+        onListening: (devServer) => {
+          if (!devServer) {
+            throw new Error('webpack-dev-server is not defined');
+          }
+
+          onListeningIsRunning = true;
+        },
+      },
+      done
+    );
+  });
+
+  afterAll(testServer.close);
+
+  it('should handle before route', () => {
+    expect(onListeningIsRunning).toBe(true);
+  });
+});
diff --git a/test/options.test.js b/test/options.test.js
index a32b5b96bc..c1ab42b5b3 100644
--- a/test/options.test.js
+++ b/test/options.test.js
@@ -244,6 +244,10 @@ describe('options', () => {
         success: [true],
         failure: [''],
       },
+      onListening: {
+        success: [() => {}],
+        failure: [''],
+      },
       open: {
         success: [true, ''],
         failure: [{}],