[custom server] Handle internal routes automatically (#1658)

* Implement the initial version.

* Improve the render logic a bit.

* Move all the webpack paths under /_next/

* Keep the log:false flag.

client/webpack-hot-middleware-client.js

-import webpackHotMiddlewareClient from 'webpack-hot-middleware/client?overlay=false&reload=true'
+import webpackHotMiddlewareClient from 'webpack-hot-middleware/client?overlay=false&reload=true&path=/_next/webpack-hmr'
 import Router from '../lib/router'
 
 const handlers = {

server/build/webpack.js

@@ -268,7 +268,7 @@ export default async function createCompiler (dir, { dev = false, quiet = false,
       path: buildDir ? join(buildDir, '.next') : join(dir, config.distDir),
       filename: '[name]',
       libraryTarget: 'commonjs2',
-      publicPath: '/_webpack/',
+      publicPath: '/_next/webpack/',
       strictModuleExceptionHandling: true,
       devtoolModuleFilenameTemplate ({ resourcePath }) {
         const hash = createHash('sha1')

server/hot-reloader.js

@@ -140,7 +140,7 @@ export default class HotReloader {
     } : {}
 
     this.webpackDevMiddleware = webpackDevMiddleware(compiler, {
-      publicPath: '/_webpack/',
+      publicPath: '/_next/webpack/',
       noInfo: true,
       quiet: true,
       clientLogLevel: 'warning',
@@ -148,7 +148,10 @@ export default class HotReloader {
       ...windowsSettings
     })
 
-    this.webpackHotMiddleware = webpackHotMiddleware(compiler, { log: false })
+    this.webpackHotMiddleware = webpackHotMiddleware(compiler, {
+      path: '/_next/webpack-hmr',
+      log: false
+    })
     this.onDemandEntries = onDemandEntryHandler(this.webpackDevMiddleware, compiler, {
       dir: this.dir,
       dev: true,

server/index.js

@@ -18,6 +18,11 @@ import getConfig from './config'
 // We need to go up one more level since we are in the `dist` directory
 import pkg from '../../package'
 
+const internalPrefixes = [
+  /^\/_next\//,
+  /^\/static\//
+]
+
 export default class Server {
   constructor ({ dir = '.', dev = false, staticMarkup = false, quiet = false } = {}) {
     this.dir = resolve(dir)
@@ -42,25 +47,27 @@ export default class Server {
     this.defineRoutes()
   }
 
-  getRequestHandler () {
-    return (req, res, parsedUrl) => {
-      // Parse url if parsedUrl not provided
-      if (!parsedUrl) {
-        parsedUrl = parseUrl(req.url, true)
-      }
-
-      // Parse the querystring ourselves if the user doesn't handle querystring parsing
-      if (typeof parsedUrl.query === 'string') {
-        parsedUrl.query = parseQs(parsedUrl.query)
-      }
+  handleRequest (req, res, parsedUrl) {
+    // Parse url if parsedUrl not provided
+    if (!parsedUrl) {
+      parsedUrl = parseUrl(req.url, true)
+    }
 
-      return this.run(req, res, parsedUrl)
-      .catch((err) => {
-        if (!this.quiet) console.error(err)
-        res.statusCode = 500
-        res.end(STATUS_CODES[500])
-      })
+    // Parse the querystring ourselves if the user doesn't handle querystring parsing
+    if (typeof parsedUrl.query === 'string') {
+      parsedUrl.query = parseQs(parsedUrl.query)
     }
+
+    return this.run(req, res, parsedUrl)
+    .catch((err) => {
+      if (!this.quiet) console.error(err)
+      res.statusCode = 500
+      res.end(STATUS_CODES[500])
+    })
+  }
+
+  getRequestHandler () {
+    return this.handleRequest.bind(this)
   }
 
   async prepare () {
@@ -181,7 +188,11 @@ export default class Server {
     }
   }
 
-  async render (req, res, pathname, query) {
+  async render (req, res, pathname, query, parsedUrl) {
+    if (this.isInternalUrl(req)) {
+      return this.handleRequest(req, res, parsedUrl)
+    }
+
     if (this.config.poweredByHeader) {
       res.setHeader('X-Powered-By', `Next.js ${pkg.version}`)
     }
@@ -291,6 +302,16 @@ export default class Server {
     }
   }
 
+  isInternalUrl (req) {
+    for (const prefix of internalPrefixes) {
+      if (prefix.test(req.url)) {
+        return true
+      }
+    }
+
+    return false
+  }
+
   readBuildId () {
     const buildIdPath = join(this.dir, this.dist, 'BUILD_ID')
     const buildId = fs.readFileSync(buildIdPath, 'utf8')