fix(hot): enable hot option as default

lib/Server.js

@@ -69,6 +69,12 @@ class Server {
 
     normalizeOptions(this.compiler, this.options);
 
+    // don't move this position because addEntries called by updateCompiler checks this.options.hot|hotOnly
+    this.options.hot =
+      typeof this.options.hot === 'boolean' || this.options.hot === 'only'
+        ? this.options.hot
+        : true;
+
     updateCompiler(this.compiler, this.options);
 
     this.heartbeatInterval = 30000;
@@ -86,7 +92,6 @@ class Server {
     this.contentBaseWatchers = [];
 
     // TODO this.<property> is deprecated (remove them in next major release.) in favor this.options.<property>
-    this.hot = this.options.hot || this.options.hotOnly;
     this.headers = this.options.headers;
     this.progress = this.options.progress;
 
@@ -732,7 +737,7 @@ class Server {
         this.sockWrite([connection], 'log-level', this.clientLogLevel);
       }
 
-      if (this.hot) {
+      if (this.options.hot === true || this.options.hot === 'only') {
         this.sockWrite([connection], 'hot');
       }
 

lib/options.json

@@ -134,10 +134,14 @@
       ]
     },
     "hot": {
-      "type": "boolean"
-    },
-    "hotOnly": {
-      "type": "boolean"
+      "anyOf": [
+        {
+          "type": "boolean"
+        },
+        {
+          "enum": ["only"]
+        }
+      ]
     },
     "http2": {
       "type": "boolean"
@@ -446,8 +450,7 @@
       "headers": "should be {Object} (https://webpack.js.org/configuration/dev-server/#devserverheaders-)",
       "historyApiFallback": "should be {Boolean|Object} (https://webpack.js.org/configuration/dev-server/#devserverhistoryapifallback)",
       "host": "should be {String|Null} (https://webpack.js.org/configuration/dev-server/#devserverhost)",
-      "hot": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhot)",
-      "hotOnly": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhotonly)",
+      "hot": "should be {Boolean|String} (https://webpack.js.org/configuration/dev-server/#devserverhot)",
       "http2": "should be {Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhttp2)",
       "https": "should be {Object|Boolean} (https://webpack.js.org/configuration/dev-server/#devserverhttps)",
       "index": "should be {String} (https://webpack.js.org/configuration/dev-server/#devserverindex)",

lib/utils/addEntries.js

@@ -43,7 +43,7 @@ function addEntries(config, options, server) {
     /** @type {(string[] | string)} */
     let hotEntry;
 
-    if (options.hotOnly) {
+    if (options.hot === 'only') {
       hotEntry = require.resolve('webpack/hot/only-dev-server');
     } else if (options.hot) {
       hotEntry = require.resolve('webpack/hot/dev-server');
@@ -141,7 +141,7 @@ function addEntries(config, options, server) {
 
       config.entry = prependEntry(config.entry || './src', additionalEntries);
 
-      if (options.hot || options.hotOnly) {
+      if (options.hot || options.hot === 'only') {
         config.plugins = config.plugins || [];
         if (
           !config.plugins.find(

lib/utils/createConfig.js

@@ -95,12 +95,6 @@ function createConfig(config, argv, { port }) {
     options.hot = argv.hot;
   }
 
-  // TODO https://github.com/webpack/webpack-dev-server/issues/616 (v4)
-  // We should prefer CLI arg under config, now we always prefer `hotOnly` from `devServer`
-  if (!options.hotOnly) {
-    options.hotOnly = argv.hotOnly;
-  }
-
   // TODO https://github.com/webpack/webpack-dev-server/issues/616 (v4)
   // We should prefer CLI arg under config, now we always prefer `clientLogLevel` from `devServer`
   if (!options.clientLogLevel && argv.clientLogLevel) {

lib/utils/updateCompiler.js

@@ -57,7 +57,7 @@ function updateCompiler(compiler, options) {
     });
 
     // do not apply the plugin unless it didn't exist before.
-    if (options.hot || options.hotOnly) {
+    if (options.hot === true || options.hot === 'only') {
       compilersWithoutHMR.forEach((compiler) => {
         // addDevServerEntrypoints above should have added the plugin
         // to the compiler options

test/__snapshots__/Validation.test.js.snap

@@ -7,7 +7,11 @@ exports[`Validation validation should fail validation for invalid \`contentBase\
 
 exports[`Validation validation should fail validation for invalid \`hot\` configuration 1`] = `
 "Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
- - configuration.hot should be a boolean."
+ - configuration.hot should be one of these:
+   boolean | \\"only\\"
+   Details:
+    * configuration.hot should be a boolean.
+    * configuration.hot should be \\"only\\"."
 `;
 
 exports[`Validation validation should fail validation for invalid \`logLevel\` configuration 1`] = `
@@ -33,5 +37,5 @@ exports[`Validation validation should fail validation for invalid \`writeToDisk\
 exports[`Validation validation should fail validation for no additional properties 1`] = `
 "Invalid configuration object. Object has been initialized using a configuration object that does not match the API schema.
  - configuration has an unknown property 'additional'. These properties are valid:
-   object { after?, allowedHosts?, before?, bonjour?, ca?, cert?, clientLogLevel?, compress?, contentBasePublicPath?, contentBase?, disableHostCheck?, features?, filename?, fs?, headers?, historyApiFallback?, host?, hot?, hotOnly?, http2?, https?, index?, injectClient?, injectHot?, inline?, key?, lazy?, liveReload?, log?, logLevel?, logTime?, mimeTypes?, noInfo?, onListening?, open?, openPage?, overlay?, pfx?, pfxPassphrase?, port?, profile?, progress?, proxy?, public?, publicPath?, quiet?, reporter?, requestCert?, serveIndex?, serverSideRender?, setup?, sockHost?, sockPath?, sockPort?, socket?, staticOptions?, stats?, transportMode?, useLocalIp?, warn?, watchContentBase?, watchOptions?, writeToDisk? }"
+   object { after?, allowedHosts?, before?, bonjour?, ca?, cert?, clientLogLevel?, compress?, contentBasePublicPath?, contentBase?, disableHostCheck?, features?, filename?, fs?, headers?, historyApiFallback?, host?, hot?, http2?, https?, index?, injectClient?, injectHot?, inline?, key?, lazy?, liveReload?, log?, logLevel?, logTime?, mimeTypes?, noInfo?, onListening?, open?, openPage?, overlay?, pfx?, pfxPassphrase?, port?, profile?, progress?, proxy?, public?, publicPath?, quiet?, reporter?, requestCert?, serveIndex?, serverSideRender?, setup?, sockHost?, sockPath?, sockPort?, socket?, staticOptions?, stats?, transportMode?, useLocalIp?, warn?, watchContentBase?, watchOptions?, writeToDisk? }"
 `;

test/e2e/Client.test.js

@@ -24,15 +24,11 @@ describe('reload', () => {
   const modes = [
     {
       title: 'hot with default transportMode.client (sockjs)',
-      options: {
-        hot: true,
-      },
       shouldRefresh: false,
     },
     {
       title: 'hot with transportMode.client ws',
       options: {
-        hot: true,
         transportMode: 'ws',
       },
       shouldRefresh: false,
@@ -110,15 +106,18 @@ describe('reload', () => {
                             const bgColor = getComputedStyle(body)[
                               'background-color'
                             ];
+
                             return bgColor;
                           })
                           .then((color2) => {
-                            browser.close().then(() => {
-                              expect(color).toEqual('rgb(0, 0, 255)');
-                              expect(color2).toEqual('rgb(255, 0, 0)');
-                              expect(refreshed).toEqual(mode.shouldRefresh);
-                              done();
-                            });
+                            expect(color).toEqual('rgb(0, 0, 255)');
+                            expect(color2).toEqual('rgb(255, 0, 0)');
+                            expect(refreshed).toEqual(mode.shouldRefresh);
+
+                            return browser.close();
+                          })
+                          .then(() => {
+                            done();
                           });
                       });
                     });

test/e2e/TransportMode.test.js

@@ -14,18 +14,21 @@ describe('transportMode client', () => {
     {
       title: 'sockjs',
       options: {
+        hot: false,
         transportMode: 'sockjs',
       },
     },
     {
       title: 'ws',
       options: {
+        hot: false,
         transportMode: 'ws',
       },
     },
     {
       title: 'custom client',
       options: {
+        hot: false,
         transportMode: {
           server: 'sockjs',
           client: require.resolve(

test/e2e/__snapshots__/ClientOptions.test.js.snap

@@ -25,12 +25,16 @@ Array [
 exports[`Client console.log liveReload disabled 1`] = `
 Array [
   "Hey.",
+  "[HMR] Waiting for update signal from WDS...",
+  "[WDS] Hot Module Replacement enabled.",
 ]
 `;
 
 exports[`Client console.log liveReload enabled 1`] = `
 Array [
   "Hey.",
+  "[HMR] Waiting for update signal from WDS...",
+  "[WDS] Hot Module Replacement enabled.",
   "[WDS] Live Reloading enabled.",
 ]
 `;

test/e2e/__snapshots__/Iframe.test.js.snap

@@ -25,12 +25,16 @@ Array [
 exports[`Client iframe console.log liveReload disabled 1`] = `
 Array [
   "Hey.",
+  "[HMR] Waiting for update signal from WDS...",
+  "[WDS] Hot Module Replacement enabled.",
 ]
 `;
 
 exports[`Client iframe console.log liveReload enabled 1`] = `
 Array [
   "Hey.",
+  "[HMR] Waiting for update signal from WDS...",
+  "[WDS] Hot Module Replacement enabled.",
   "[WDS] Live Reloading enabled.",
 ]
 `;

test/fixtures/schema/webpack.config.no-dev-stats.js

@@ -13,7 +13,6 @@ module.exports = {
     publicPath: '_publicPath',
     filename: '_filename',
     hot: '_hot',
-    hotOnly: '_hotOnly',
     clientLogLevel: '_clientLogLevel',
     contentBase: '_contentBase',
     watchContentBase: '_watchContentBase',

test/helpers/test-server.js

@@ -23,7 +23,6 @@ function startFullSetup(config, options, done) {
   if (
     options.inline === undefined &&
     options.hot === undefined &&
-    options.hotOnly === undefined &&
     options.liveReload === undefined
   ) {
     options.inline = false;

test/options.test.js

@@ -188,12 +188,8 @@ describe('options', () => {
         failure: [false],
       },
       hot: {
-        success: [true],
-        failure: [''],
-      },
-      hotOnly: {
-        success: [true],
-        failure: [''],
+        success: [true, 'only'],
+        failure: ['', 'foo'],
       },
       http2: {
         success: [true],

test/ports-map.js

@@ -21,7 +21,6 @@ const portsList = {
   'historyApiFallback-option': 1,
   'host-option': 1,
   'hot-option': 1,
-  'hotOnly-option': 1,
   'http2-option': 1,
   'https-option': 1,
   'inline-option': 1,

test/server/Server.test.js

@@ -50,12 +50,12 @@ describe('Server', () => {
       compiler.run(() => {});
     });
 
-    it('add hotOnly option', (done) => {
+    it('add hot-only option', (done) => {
       const compiler = webpack(config);
       const server = new Server(
         compiler,
         Object.assign({}, baseDevConfig, {
-          hotOnly: true,
+          hot: 'only',
         })
       );
 

test/server/__snapshots__/Server.test.js.snap

@@ -19,7 +19,7 @@ Array [
 ]
 `;
 
-exports[`Server addEntries add hotOnly option 1`] = `
+exports[`Server addEntries add hot-only option 1`] = `
 Array [
   Array [
     "client",

test/server/__snapshots__/transportMode-option.test.js.snap

@@ -87,7 +87,7 @@ Array [
   Object {
     "foo": "bar",
   },
-  "{\\"type\\":\\"liveReload\\"}",
+  "{\\"type\\":\\"hot\\"}",
 ]
 `;
 
@@ -96,11 +96,20 @@ Array [
   Object {
     "foo": "bar",
   },
-  "{\\"type\\":\\"ok\\"}",
+  "{\\"type\\":\\"liveReload\\"}",
 ]
 `;
 
 exports[`transportMode server server should use server implementation correctly 5`] = `
+Array [
+  Object {
+    "foo": "bar",
+  },
+  "{\\"type\\":\\"ok\\"}",
+]
+`;
+
+exports[`transportMode server server should use server implementation correctly 6`] = `
 Array [
   Array [
     Object {

test/server/hot-option.test.js

@@ -15,7 +15,6 @@ describe('hot option', () => {
       const options = {
         port,
         inline: true,
-        hot: true,
         watchOptions: {
           poll: true,
         },
@@ -31,12 +30,34 @@ describe('hot option', () => {
     });
   });
 
+  describe('simple hot-only config entries', () => {
+    beforeAll((done) => {
+      const options = {
+        port,
+        inline: true,
+        hot: 'only',
+        watchOptions: {
+          poll: true,
+        },
+      };
+      server = testServer.startAwaitingCompilation(config, options, done);
+      req = request(server.app);
+    });
+
+    afterAll(testServer.close);
+
+    it('should include hot-only script in the bundle', (done) => {
+      req
+        .get('/main.js')
+        .expect(200, /webpack\/hot\/only-dev-server\.js/, done);
+    });
+  });
+
   describe('multi compiler hot config entries', () => {
     beforeAll((done) => {
       const options = {
         port,
         inline: true,
-        hot: true,
         watchOptions: {
           poll: true,
         },
@@ -92,7 +113,6 @@ describe('hot option', () => {
       const options = {
         port,
         inline: true,
-        hot: true,
         watchOptions: {
           poll: true,
         },
@@ -126,7 +146,6 @@ describe('hot option', () => {
       const options = {
         port,
         inline: true,
-        hot: true,
         watchOptions: {
           poll: true,
         },