Setup initial mock url request job tests for Cronet

components/cronet/android/test/cronet_tests_jni.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <jni.h>
 
 #include "base/android/base_jni_registrar.h"
 #include "base/android/jni_android.h"
 #include "base/android/jni_registrar.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/macros.h"
+#include "base/message_loop/message_loop.h"
+#include "base/path_service.h"
 #include "components/cronet/android/cronet_loader.h"
+#include "net/base/net_errors.h"
+#include "net/test/url_request/url_request_failed_job.h"
+#include "net/test/url_request/url_request_mock_http_job.h"
+#include "net/url_request/url_request_filter.h"
+#include "net/url_request/url_request_interceptor.h"
 
 namespace {
 
+// A mock URL that will produces a redirect.
+const char kMockCronetTestRedirectUrl[] = "http://mock.cronet.redirect/";
+
+// A mock URL that will return a 404 response.
+const char kMockCronetTestSuccessUrl[] = "http://mock.cronet.success/";
+
+// A mock URL that will result in a failed url request.
+const char kMockCronetTestFailedUrl[] = "http://mock.cronet.failed/";
+
 const base::android::RegistrationMethod kCronetTestsRegisteredMethods[] = {
   {"BaseAndroid", base::android::RegisterJni},
 };
 
+class CronetMockJobInterceptor : public net::URLRequestInterceptor {

[mef, 2014/09/19 14:12:00]

Suggest: move CronetMockJobInterceptor into its own module, so
cronet_tests_jni.cc is purely jni load stuff.

[xunjieli, 2014/09/19 15:00:04]

Done.

+ public:
+  CronetMockJobInterceptor() {}
+  virtual ~CronetMockJobInterceptor() {}
+
+  // net::URLRequestInterceptor implementation
+  virtual net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const OVERRIDE {
+    base::FilePath test_files_root;
+    PathService::Get(base::DIR_ANDROID_APP_DATA, &test_files_root);
+    if (request->url() == GURL(kMockCronetTestRedirectUrl)) {

[mef, 2014/09/19 14:12:00]

Would it make sense to make some kind of map between URL and test file, or just
extract test file name from URL?
This would help scaling to more tests.

[xunjieli, 2014/09/19 15:00:04]

Acknowledged. I think this is a great idea. But right now I am not very sure how
the failures-during-different-stages-tests will look like, and whether we need
other types of Mock Interceptors. I have added your suggestion as a TODO. I will
try to fix this potential code duplication problem in the next CL.

+      return new net::URLRequestMockHTTPJob(
+          request,
+          network_delegate,
+          test_files_root.Append("redirect.html"),
+          base::MessageLoop::current()->message_loop_proxy());
+    }
+    if (request->url() == GURL(kMockCronetTestSuccessUrl)) {
+      return new net::URLRequestMockHTTPJob(
+          request,
+          network_delegate,
+          test_files_root.Append("success.html"),
+          base::MessageLoop::current()->message_loop_proxy());
+    }
+    return new net::URLRequestFailedJob(
+        request, network_delegate, net::ERR_FAILED);
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CronetMockJobInterceptor);
+};
+
+bool AddUrlInterceptors() {
+  net::URLRequestFilter* filter = net::URLRequestFilter::GetInstance();
+  return filter->AddUrlInterceptor(GURL(kMockCronetTestSuccessUrl),
+                                   scoped_ptr<net::URLRequestInterceptor>(
+                                       new CronetMockJobInterceptor())) &&
+         filter->AddUrlInterceptor(GURL(kMockCronetTestRedirectUrl),

[mef, 2014/09/19 14:12:00]

Again, having a map / list and a loop would avoid cut-n-paste.

[xunjieli, 2014/09/19 15:00:04]

Acknowledged. Will tackle this in the next CL when I am more clear about what
kind of mock interceptors we need :)

+                                   scoped_ptr<net::URLRequestInterceptor>(
+                                       new CronetMockJobInterceptor())) &&
+         filter->AddUrlInterceptor(GURL(kMockCronetTestFailedUrl),
+                                   scoped_ptr<net::URLRequestInterceptor>(
+                                       new CronetMockJobInterceptor()));
+}
+
 }  // namespace
 
 // This is called by the VM when the shared library is first loaded.
 // Checks the available version of JNI. Also, caches Java reflection artifacts.
 extern "C" jint JNI_OnLoad(JavaVM* vm, void* reserved) {
   JNIEnv* env;
   if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
     return -1;
   }
 
   jint cronet_onload = cronet::CronetOnLoad(vm, reserved);
   if (cronet_onload == -1)
     return cronet_onload;
 
   if (!base::android::RegisterNativeMethods(
           env,
           kCronetTestsRegisteredMethods,
           arraysize(kCronetTestsRegisteredMethods))) {
     return -1;
   }
+
+  if (!AddUrlInterceptors())
+    return -1;
   return cronet_onload;
 }
 
 extern "C" void JNI_OnUnLoad(JavaVM* vm, void* reserved) {
+  net::URLRequestFilter::GetInstance()->ClearHandlers();
   cronet::CronetOnUnLoad(vm, reserved);
 }