Add custom webpack dev middleware config (vercel#1931)

timneutkens · arunoda · commit b8f336c74710 · 2017-05-13T16:44:21.000-07:00
diff --git a/readme.md b/readme.md
@@ -682,9 +682,15 @@ In order to extend our usage of `webpack`, you can define a function that extend
 
 module.exports = {
   webpack: (config, { dev }) => {
-    // Perform customizations to config
-    
-    // Important: return the modified 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
   }
 }
diff --git a/server/config.js b/server/config.js
@@ -5,6 +5,7 @@ const cache = new Map()
 
 const defaultConfig = {
   webpack: null,
+  webpackDevMiddleware: null,
   poweredByHeader: true,
   distDir: '.next',
   assetPrefix: ''
diff --git a/server/hot-reloader.js b/server/hot-reloader.js
@@ -138,14 +138,21 @@ export default class HotReloader {
       }
     } : {}
 
-    this.webpackDevMiddleware = webpackDevMiddleware(compiler, {
+    let webpackDevMiddlewareConfig = {
       publicPath: '/_next/webpack/',
       noInfo: true,
       quiet: true,
       clientLogLevel: 'warning',
       watchOptions: { ignored },
       ...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, {
       path: '/_next/webpack-hmr',
