base/test/test_message_loop.h

// Copyright 2016 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_TEST_TEST_MESSAGE_LOOP_H_
#define BASE_TEST_TEST_MESSAGE_LOOP_H_

#include "base/message_loop/message_pump_type.h"
#include "base/task/single_thread_task_runner.h"
#include "base/test/task_environment.h"

namespace base {

// TestMessageLoop is a convenience class for unittests that need to create a
// message loop without a real thread backing it. For most tests,
// it is sufficient to just instantiate TestMessageLoop as a member variable.
//
// TestMessageLoop will attempt to drain the underlying MessageLoop on
// destruction for clean teardown of tests.
//
// TODO(b/891670): Get rid of this and migrate users to
// SingleThreadTaskEnvironment
class TestMessageLoop {
 public:
  TestMessageLoop();
  explicit TestMessageLoop(MessagePumpType type);
  ~TestMessageLoop();

  scoped_refptr<SingleThreadTaskRunner> task_runner() {
    return task_environment_.GetMainThreadTaskRunner();
  }

 private:
  test::SingleThreadTaskEnvironment task_environment_;
};

}  // namespace base

#endif  // BASE_TEST_TEST_MESSAGE_LOOP_H_