Index: base/test/mock_log.h |
diff --git a/base/test/mock_log.h b/base/test/mock_log.h |
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+// Copyright 2015 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. |
+ |
+#ifndef BASE_TEST_MOCK_LOG_H_ |
+#define BASE_TEST_MOCK_LOG_H_ |
+ |
+#include <string> |
+ |
+#include "base/logging.h" |
+#include "base/macros.h" |
+#include "base/synchronization/lock.h" |
+#include "testing/gmock/include/gmock/gmock.h" |
+ |
+namespace base { |
+namespace test { |
+ |
+// A MockLog object intercepts LOG() messages issued during its lifespan. Using |
+// this together with gMock, it's very easy to test how a piece of code calls |
+// LOG(). The typical usage: |
+// |
+// TEST(FooTest, LogsCorrectly) { |
+// MockLog log; |
+// |
+// // We expect the WARNING "Something bad!" exactly twice. |
+// EXPECT_CALL(log, Log(WARNING, _, "Something bad!")) |
+// .Times(2); |
+// |
+// // We allow foo.cc to call LOG(INFO) any number of times. |
+// EXPECT_CALL(log, Log(INFO, HasSubstr("/foo.cc"), _)) |
+// .Times(AnyNumber()); |
+// |
+// log.StartCapturingLogs(); // Call this after done setting expectations. |
+// Foo(); // Exercises the code under test. |
+// } |
+// |
+// CAVEAT: base/logging does not allow a thread to call LOG() again when it's |
+// already inside a LOG() call. Doing so will cause a deadlock. Therefore, |
+// it's the user's responsibility to not call LOG() in an action triggered by |
+// MockLog::Log(). You may call RAW_LOG() instead. |
+class MockLog { |
+ public: |
+ // Creates a MockLog object that is not capturing logs. If it were to start |
+ // to capture logs, it could be a problem if some other threads already exist |
+ // and are logging, as the user hasn't had a chance to set up expectation on |
+ // this object yet (calling a mock method before setting the expectation is |
+ // UNDEFINED behavior). |
+ MockLog(); |
+ |
+ // When the object is destructed, it stops intercepting logs. |
+ ~MockLog(); |
+ |
+ // Starts log capturing if the object isn't already doing so. |
+ // Otherwise crashes. |
+ void StartCapturingLogs(); |
+ |
+ // Stops log capturing if the object is capturing logs. Otherwise crashes. |
+ void StopCapturingLogs(); |
+ |
+ // Log method is invoked for every log message before it's sent to other log |
+ // destinations (if any). The method should return true to signal that it |
+ // handled the message and the message should not be sent to other log |
+ // destinations. |
+ MOCK_METHOD5(Log, |
+ bool(int severity, |
+ const char* file, |
+ int line, |
+ size_t message_start, |
+ const std::string& str)); |
+ |
+ private: |
+ // The currently active mock log. |
+ static MockLog* g_instance_; |
+ |
+ // Lock protecting access to g_instance_. |
+ static Lock g_lock; |
+ |
+ // Static function which is set as the logging message handler. |
+ // Called once for each message. |
+ static bool LogMessageHandler(int severity, |
+ const char* file, |
+ int line, |
+ size_t message_start, |
+ const std::string& str); |
+ |
+ // True if this object is currently capturing logs. |
+ bool is_capturing_logs_; |
+ |
+ // The previous handler to restore when the MockLog is destroyed. |
+ logging::LogMessageHandlerFunction previous_handler_; |
+ |
+ DISALLOW_COPY_AND_ASSIGN(MockLog); |
+}; |
+ |
+} // namespace test |
+} // namespace base |
+ |
+#endif // BASE_TEST_MOCK_LOG_H_ |