From 51b4206721a333a14b7ff8e2341c6a3a8fc7a632 Mon Sep 17 00:00:00 2001
From: Islam Sharabash <islam.sharabash@gmail.com>
Date: Wed, 18 May 2016 17:49:29 -0700
Subject: [PATCH] feat: adding support for before middleware

---
 docs/config/01-configuration-file.md |  8 ++++++
 lib/web-server.js                    | 27 ++++++++++++--------
 test/unit/web-server.spec.js         | 38 ++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 10 deletions(-)

diff --git a/docs/config/01-configuration-file.md b/docs/config/01-configuration-file.md
index 793683d4f..dd8c2c17e 100644
--- a/docs/config/01-configuration-file.md
+++ b/docs/config/01-configuration-file.md
@@ -459,6 +459,14 @@ mime: {
 ```
 
 
+## beforeMiddleware
+**Type:** Array
+
+**Default:** `[]`
+
+**Description:** This is the same as middleware except that these middleware will be run before karma's own middleware.
+
+
 ## plugins
 **Type:** Array
 
diff --git a/lib/web-server.js b/lib/web-server.js
index 1405032c0..2f5426c29 100644
--- a/lib/web-server.js
+++ b/lib/web-server.js
@@ -57,16 +57,23 @@ var createWebServer = function (injector, emitter, fileList) {
 
   log.debug('Instantiating middleware')
   var handler = connect()
-    .use(injector.invoke(runnerMiddleware.create))
-    .use(injector.invoke(stopperMiddleware.create))
-    .use(injector.invoke(stripHostMiddleware.create))
-    .use(injector.invoke(karmaMiddleware.create))
-    .use(injector.invoke(sourceFilesMiddleware.create))
-    // TODO(vojta): extract the proxy into a plugin
-    .use(proxyMiddlewareInstance)
-    // TODO(vojta): remove, this is only here because of karma-dart
-    // we need a better way of custom handlers
-    .use(injector.invoke(createCustomHandler))
+
+  if (config.beforeMiddleware) {
+    config.beforeMiddleware.forEach(function (middleware) {
+      handler.use(injector.get('middleware:' + middleware))
+    })
+  }
+
+  handler.use(injector.invoke(runnerMiddleware.create))
+  handler.use(injector.invoke(stopperMiddleware.create))
+  handler.use(injector.invoke(stripHostMiddleware.create))
+  handler.use(injector.invoke(karmaMiddleware.create))
+  handler.use(injector.invoke(sourceFilesMiddleware.create))
+  // TODO(vojta): extract the proxy into a plugin
+  handler.use(proxyMiddlewareInstance)
+  // TODO(vojta): remove, this is only here because of karma-dart
+  // we need a better way of custom handlers
+  handler.use(injector.invoke(createCustomHandler))
 
   if (config.middleware) {
     config.middleware.forEach(function (middleware) {
diff --git a/test/unit/web-server.spec.js b/test/unit/web-server.spec.js
index d60f45bfb..8bd120b2a 100644
--- a/test/unit/web-server.spec.js
+++ b/test/unit/web-server.spec.js
@@ -33,6 +33,7 @@ describe('web-server', () => {
   // this relies on the fact that none of these tests mutate fs
   var m = mocks.loadFile(path.join(__dirname, '/../../lib/web-server.js'), _mocks, _globals)
   var customFileHandlers = server = emitter = null
+  var beforeMiddlewareActive = false
   var middlewareActive = false
   var servedFiles = (files) => {
     emitter.emit('file_list_modified', {included: [], served: files})
@@ -45,6 +46,7 @@ describe('web-server', () => {
       var config = {
         basePath: '/base/path',
         urlRoot: '/',
+        beforeMiddleware: ['beforeCustom'],
         middleware: ['custom'],
         middlewareResponse: 'hello middleware!',
         mime: {'custom/custom': ['custom']}
@@ -59,6 +61,15 @@ describe('web-server', () => {
         reporter: ['value', null],
         executor: ['value', null],
         proxies: ['value', null],
+        'middleware:beforeCustom': ['factory', function (config) {
+          return function (request, response, next) {
+            if (beforeMiddlewareActive) {
+              response.writeHead(223)
+              return response.end('hello from before middleware!')
+            }
+            next()
+          }
+        }],
         'middleware:custom': ['factory', function (config) {
           return function (request, response, next) {
             if (middlewareActive) {
@@ -106,12 +117,39 @@ describe('web-server', () => {
         .expect(200, 'new-js-source')
     })
 
+    describe('beforeMiddleware', () => {
+      beforeEach(() => {
+        servedFiles(new Set([new File('/base/path/one.js')]))
+        beforeMiddlewareActive = true
+      })
+
+      afterEach(() => {
+        beforeMiddlewareActive = false
+      })
+
+      it('should use injected middleware', () => {
+        return request(server)
+          .get('/base/other.js')
+          .expect(223, 'hello from before middleware!')
+      })
+
+      it('should inject middleware before served files', () => {
+        return request(server)
+          .get('/base/one.js')
+          .expect(223, 'hello from before middleware!')
+      })
+    })
+
     describe('middleware', () => {
       beforeEach(() => {
         servedFiles(new Set([new File('/base/path/one.js')]))
         middlewareActive = true
       })
 
+      afterEach(() => {
+        middlewareActive = false
+      })
+
       it('should use injected middleware', () => {
         return request(server)
           .get('/base/other.js')