Part 1 of work to do user sign in based on OAuth2:

chrome/common/net/gaia/oauth2_access_token_fetcher_unittest.cc

+// Copyright (c) 2011 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.
+//
+// A complete set of unit tests for OAuth2AccessTokenFetcher.
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/message_loop.h"
+#include "chrome/common/net/gaia/gaia_urls.h"
+#include "chrome/common/net/gaia/google_service_auth_error.h"
+#include "chrome/common/net/http_return.h"
+#include "chrome/common/net/gaia/oauth2_access_token_consumer.h"
+#include "chrome/common/net/gaia/oauth2_access_token_fetcher.h"
+#include "chrome/test/base/testing_profile.h"
+#include "content/public/common/url_fetcher.h"
+#include "content/public/common/url_fetcher_delegate.h"
+#include "content/public/common/url_fetcher_factory.h"
+#include "content/test/test_browser_thread.h"
+#include "content/test/test_url_fetcher_factory.h"
+#include "googleurl/src/gurl.h"
+#include "net/url_request/url_request.h"
+#include "net/url_request/url_request_status.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using content::BrowserThread;
+using content::URLFetcher;
+using content::URLFetcherDelegate;
+using content::URLFetcherFactory;
+using net::ResponseCookies;
+using net::URLRequestStatus;
+using testing::_;
+using testing::Return;
+
+namespace {
+static const char kValidTokenResponse[] =
+    "{"
+    "  \"access_token\": \"at1\","
+    "  \"expires_in\": 3600,"
+    "  \"token_type\": \"Bearer\""
+    "}";
+static const char kTokenResponseNoAccessToken[] =
+    "{"
+    "  \"expires_in\": 3600,"
+    "  \"token_type\": \"Bearer\""
+    "}";
+}
+
+class MockUrlFetcherFactory : public ScopedURLFetcherFactory,
+                              public URLFetcherFactory {
+public:
+  MockUrlFetcherFactory()
+      : ScopedURLFetcherFactory(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+  }
+  virtual ~MockUrlFetcherFactory() {}
+
+  MOCK_METHOD4(
+      CreateURLFetcher,
+      URLFetcher* (int id,
+                   const GURL& url,
+                   URLFetcher::RequestType request_type,
+                   URLFetcherDelegate* d));
+};
+
+class MockOAuth2AccessTokenConsumer : public OAuth2AccessTokenConsumer {
+ public:
+  MockOAuth2AccessTokenConsumer() {}
+  ~MockOAuth2AccessTokenConsumer() {}
+
+  MOCK_METHOD1(OnGetTokenSuccess, void(const std::string& access_token));
+  MOCK_METHOD1(OnGetTokenFailure,
+               void(const GoogleServiceAuthError& error));
+};
+
+class OAuth2AccessTokenFetcherTest : public testing::Test {
+ public:
+  OAuth2AccessTokenFetcherTest()
+    : ui_thread_(BrowserThread::UI, &message_loop_),
+      fetcher_(&consumer_, profile_.GetRequestContext(), "test") {
+  }
+
+  virtual ~OAuth2AccessTokenFetcherTest() { }
+
+  virtual TestURLFetcher* SetupGetAccessToken(
+      bool fetch_succeeds, int response_code, const std::string& body) {
+    GURL url(GaiaUrls::GetInstance()->oauth2_token_url());
+    TestURLFetcher* url_fetcher = new TestURLFetcher(0, url, &fetcher_);
+    URLRequestStatus::Status status =
+        fetch_succeeds ? URLRequestStatus::SUCCESS : URLRequestStatus::FAILED;
+    url_fetcher->set_status(URLRequestStatus(status, 0));
+
+    if (response_code != 0)
+      url_fetcher->set_response_code(response_code);
+
+    if (!body.empty())
+      url_fetcher->SetResponseString(body);
+
+    EXPECT_CALL(factory_, CreateURLFetcher(_, url, _, _))
+        .WillOnce(Return(url_fetcher));
+    return url_fetcher;
+  }
+
+ protected:
+  MessageLoop message_loop_;
+  content::TestBrowserThread ui_thread_;
+  MockUrlFetcherFactory factory_;
+  MockOAuth2AccessTokenConsumer consumer_;
+  TestingProfile profile_;
+  OAuth2AccessTokenFetcher fetcher_;
+};
+
+TEST_F(OAuth2AccessTokenFetcherTest, GetAccessTokenRequestFailure) {
+  TestURLFetcher* url_fetcher = SetupGetAccessToken(false, 0, "");
+  EXPECT_CALL(consumer_, OnGetTokenFailure(_)).Times(1);
+  fetcher_.Start("refresh_token");
+  fetcher_.OnURLFetchComplete(url_fetcher);
+}
+
+TEST_F(OAuth2AccessTokenFetcherTest, GetAccessTokenResponseCodeFailure) {
+  TestURLFetcher* url_fetcher = SetupGetAccessToken(true, RC_FORBIDDEN, "");
+  EXPECT_CALL(consumer_, OnGetTokenFailure(_)).Times(1);
+  fetcher_.Start("refresh_token");
+  fetcher_.OnURLFetchComplete(url_fetcher);
+}
+
+TEST_F(OAuth2AccessTokenFetcherTest, GetAccessTokenResponseNoAccessToken) {
+  TestURLFetcher* url_fetcher = SetupGetAccessToken(
+      true, RC_REQUEST_OK, kTokenResponseNoAccessToken);
+  EXPECT_CALL(consumer_, OnGetTokenFailure(_)).Times(1);
+  fetcher_.Start("refresh_token");
+  fetcher_.OnURLFetchComplete(url_fetcher);
+}
+
+TEST_F(OAuth2AccessTokenFetcherTest, Success) {
+  TestURLFetcher* url_fetcher = SetupGetAccessToken(
+      true, RC_REQUEST_OK, kValidTokenResponse);
+  EXPECT_CALL(consumer_, OnGetTokenSuccess("at1")).Times(1);
+  fetcher_.Start("refresh_token");
+  fetcher_.OnURLFetchComplete(url_fetcher);
+}
+
+TEST_F(OAuth2AccessTokenFetcherTest, ParseGetAccessTokenResponse) {
+  {  // No body.
+    TestURLFetcher url_fetcher(0, GURL("www.google.com"), NULL);
+
+    std::string at;
+    EXPECT_FALSE(OAuth2AccessTokenFetcher::ParseGetAccessTokenResponse(
+        &url_fetcher, &at));
+    EXPECT_TRUE(at.empty());
+  }
+  {  // Bad json.
+    TestURLFetcher url_fetcher(0, GURL("www.google.com"), NULL);
+    url_fetcher.SetResponseString("foo");
+
+    std::string at;
+    EXPECT_FALSE(OAuth2AccessTokenFetcher::ParseGetAccessTokenResponse(
+        &url_fetcher, &at));
+    EXPECT_TRUE(at.empty());
+  }
+  {  // Valid json: access token missing.
+    TestURLFetcher url_fetcher(0, GURL("www.google.com"), NULL);
+    url_fetcher.SetResponseString(kTokenResponseNoAccessToken);
+
+    std::string at;
+    EXPECT_FALSE(OAuth2AccessTokenFetcher::ParseGetAccessTokenResponse(
+        &url_fetcher, &at));
+    EXPECT_TRUE(at.empty());
+  }
+  {  // Valid json: all good.
+    TestURLFetcher url_fetcher(0, GURL("www.google.com"), NULL);
+    url_fetcher.SetResponseString(kValidTokenResponse);
+
+    std::string at;
+    EXPECT_TRUE(OAuth2AccessTokenFetcher::ParseGetAccessTokenResponse(
+        &url_fetcher, &at));
+    EXPECT_EQ("at1", at);
+  }
+}