Use entry option instead of custom make hook (#14527)

Simplifies on-demand-entries a bit.

packages/next/build/webpack-config.ts

@@ -694,11 +694,15 @@ export default async function getBaseWebpackConfig(
           : {}),
       }
     },
+    watchOptions: {
+      ignored: ['.git/**', 'node_modules/**', '.git/**'],
+    },
     output: {
       path: outputPath,
       // On the server we don't use the chunkhash
       filename: dev || isServer ? '[name].js' : '[name]-[chunkhash].js',
-      libraryTarget: isServer ? 'commonjs2' : 'var',
+      library: isServer ? undefined : '_N_E',
+      libraryTarget: isServer ? 'commonjs2' : 'assign',
       hotUpdateChunkFilename: isWebpack5
         ? 'static/webpack/[id].[fullhash].hot-update.js'
         : 'static/webpack/[id].[hash].hot-update.js',
@@ -894,16 +898,9 @@ export default async function getBaseWebpackConfig(
             const {
               NextJsRequireCacheHotReloader,
             } = require('./webpack/plugins/nextjs-require-cache-hot-reloader')
-            const {
-              UnlinkRemovedPagesPlugin,
-            } = require('./webpack/plugins/unlink-removed-pages-plugin')
-            const devPlugins = [
-              new UnlinkRemovedPagesPlugin(),
-              new NextJsRequireCacheHotReloader(),
-            ]
+            const devPlugins = [new NextJsRequireCacheHotReloader()]
 
-            // Webpack 5 enables HMR automatically in the development mode
-            if (!isServer && !isWebpack5) {
+            if (!isServer) {
               devPlugins.push(new webpack.HotModuleReplacementPlugin())
             }
 
@@ -1038,6 +1035,16 @@ export default async function getBaseWebpackConfig(
     }
   }
 
+  // Backwards compat with webpack-dev-middleware options object
+  if (typeof config.webpackDevMiddleware === 'function') {
+    const options = config.webpackDevMiddleware({
+      watchOptions: webpackConfig.watchOptions,
+    })
+    if (options.watchOptions) {
+      webpackConfig.watchOptions = options.watchOptions
+    }
+  }
+
   function canMatchCss(rule: webpack.RuleSetCondition | undefined): boolean {
     if (!rule) {
       return false
@@ -1262,16 +1269,5 @@ export default async function getBaseWebpackConfig(
     webpackConfig.entry = await (webpackConfig.entry as webpack.EntryFunc)()
   }
 
-  // In webpack 5, the 'var' libraryTarget output requires a name.
-  // TODO: this should be revisited as 'var' was only used to not have the
-  // initial variable exposed. In webpack 4, not setting the library option
-  // would result in the bundle being a self-executing function without the
-  // variable.
-  if (isWebpack5 && !isServer) {
-    webpackConfig.output!.library = webpackConfig.output?.library
-      ? webpackConfig.output.library
-      : 'INTERNAL_NEXT_APP'
-  }
-
   return webpackConfig
 }

packages/next/build/webpack/plugins/build-manifest-plugin.ts

@@ -41,7 +41,8 @@ function generateClientManifest(
 }
 
 function isJsFile(file: string): boolean {
-  return file.endsWith('.js')
+  // We don't want to include `.hot-update.js` files into the initial page
+  return !file.endsWith('.hot-update.js') && file.endsWith('.js')
 }
 
 // This plugin creates a build-manifest.json for all assets that are being output

packages/next/package.json

@@ -151,7 +151,6 @@
     "@types/styled-jsx": "2.2.8",
     "@types/terser-webpack-plugin": "2.2.0",
     "@types/text-table": "0.2.1",
-    "@types/webpack-dev-middleware": "2.0.3",
     "@types/webpack-hot-middleware": "2.16.5",
     "@types/webpack-sources": "0.1.5",
     "@zeit/ncc": "0.22.0",
@@ -213,7 +212,6 @@
     "typescript": "3.8.3",
     "unfetch": "4.1.0",
     "unistore": "3.4.1",
-    "webpack-dev-middleware": "3.7.0",
     "webpack-hot-middleware": "2.25.0"
   },
   "engines": {