Add support for custom hot reload config

README.md

@@ -494,11 +494,19 @@ In order to extend our usage of `webpack`, you can define a function that extend
 
 module.exports = {
   webpack: (config, { dev }) => {
-    // Perform customizations to config
+    // Perform customizations to webpack config
 
     // Important: return the modified config
     return config
-  }
+  },
+  webpackDevMiddleware: (config) => {
+    // Perform customizations to webpack dev middleware config
+
+    // Important: return the modified config
+    return config
+  },
+  // Enable / disable X-Powered-By, enabled by default
+  poweredByHeader: true
 }
 ```
 

server/config.js

@@ -5,6 +5,7 @@ const cache = new Map()
 
 const defaultConfig = {
   webpack: null,
+  webpackDevMiddleware: null,
   poweredByHeader: true
 }
 

server/hot-reloader.js

@@ -5,9 +5,11 @@ import isWindowsBash from 'is-windows-bash'
 import webpack from './build/webpack'
 import clean from './build/clean'
 import readPage from './read-page'
+import getConfig from './config'
 
 export default class HotReloader {
   constructor (dir, { quiet } = {}) {
+    this.config = getConfig(dir)
     this.dir = dir
     this.quiet = quiet
     this.middlewares = []
@@ -130,7 +132,7 @@ export default class HotReloader {
       }
     } : {}
 
-    this.webpackDevMiddleware = webpackDevMiddleware(compiler, {
+    let webpackDevMiddlewareConfig = {
       publicPath: '/_webpack/',
       noInfo: true,
       quiet: true,
@@ -142,7 +144,14 @@ export default class HotReloader {
         ]
       },
       ...windowsSettings
-    })
+    }
+
+    if (this.config.webpackDevMiddleware) {
+      console.log('> Using "webpackDevMiddleware" config function defined in next.config.js.')
+      webpackDevMiddlewareConfig = this.config.webpackDevMiddleware(webpackDevMiddlewareConfig)
+    }
+
+    this.webpackDevMiddleware = webpackDevMiddleware(compiler, webpackDevMiddlewareConfig)
 
     this.webpackHotMiddleware = webpackHotMiddleware(compiler, { log: false })