GetTimeToCallback() returns estimated time to callback.

base/timer/timer_unittest.cc

 // Copyright (c) 2012 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 "base/timer/timer.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 580 matching lines @@
               false);
   EXPECT_FALSE(timer.IsRunning());
   timer.Reset();
   EXPECT_TRUE(timer.IsRunning());
   timer.Stop();
   EXPECT_FALSE(timer.IsRunning());
   timer.Reset();
   EXPECT_TRUE(timer.IsRunning());
 }
 
+//-----------------------------------------------------------------------------
+
+TEST(TimerTest, RetainRepeatGetTimeToCallback) {
+  MessageLoop loop;
+  Timer timer(FROM_HERE, TimeDelta::FromDays(1), Bind(&TimerTestCallback),
+              true);
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Reset();
+  EXPECT_NE(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Stop();
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Reset();
+  EXPECT_NE(TimeDelta::Max(), timer.GetTimeToCallback());
+}
+
+TEST(TimerTest, RetainNonRepeatGetTimeToCallback) {
+  MessageLoop loop;
+  Timer timer(FROM_HERE, TimeDelta::FromDays(1), Bind(&TimerTestCallback),
+              false);
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Reset();
+  EXPECT_NE(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Stop();
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Reset();
+  EXPECT_NE(TimeDelta::Max(), timer.GetTimeToCallback());
+}
+
+TEST(TimerTest, OneShotTimerWithTickClockGetTimeToCallback) {
+  scoped_refptr<TestMockTimeTaskRunner> task_runner(
+      new TestMockTimeTaskRunner(Time::Now(), TimeTicks::Now()));
+  std::unique_ptr<TickClock> tick_clock(task_runner->GetMockTickClock());
+  MessageLoop message_loop;
+  message_loop.SetTaskRunner(task_runner);
+  Receiver receiver;
+  OneShotTimer timer(tick_clock.get());
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+  timer.Start(FROM_HERE, TimeDelta::FromSeconds(2),
+              Bind(&Receiver::OnCalled, Unretained(&receiver)));
+  EXPECT_EQ(TimeDelta::FromSeconds(2), timer.GetTimeToCallback());
+  task_runner->FastForwardBy(TimeDelta::FromSeconds(1));
+  EXPECT_EQ(TimeDelta::FromSeconds(1), timer.GetTimeToCallback());
+  task_runner->FastForwardBy(TimeDelta::FromSeconds(1));
+  EXPECT_TRUE(receiver.WasCalled());
+  EXPECT_EQ(TimeDelta::Max(), timer.GetTimeToCallback());
+}
+
+TEST(TimerTest, RepeatingTimerWithTickClockTimeToCallback) {
+  scoped_refptr<TestMockTimeTaskRunner> task_runner(
+      new TestMockTimeTaskRunner(Time::Now(), TimeTicks::Now()));
+  std::unique_ptr<TickClock> tick_clock(task_runner->GetMockTickClock());
+  MessageLoop message_loop;
+  message_loop.SetTaskRunner(task_runner);
+  Receiver receiver;
+  RepeatingTimer timer(tick_clock.get());
+  timer.Start(FROM_HERE, TimeDelta::FromSeconds(2),
+              Bind(&Receiver::OnCalled, Unretained(&receiver)));
+  EXPECT_EQ(TimeDelta::FromSeconds(2), timer.GetTimeToCallback());
+  task_runner->FastForwardBy(TimeDelta::FromSeconds(1));
+  EXPECT_EQ(TimeDelta::FromSeconds(1), timer.GetTimeToCallback());
+  task_runner->FastForwardBy(TimeDelta::FromSeconds(1));
+  EXPECT_EQ(TimeDelta::FromSeconds(2), timer.GetTimeToCallback());
+}
+
 namespace {
 
 bool g_callback_happened1 = false;
 bool g_callback_happened2 = false;
 
 void ClearAllCallbackHappened() {
   g_callback_happened1 = false;
   g_callback_happened2 = false;
 }
 
@@ skipping 34 matching lines @@
                 Bind(&SetCallbackHappened1));
     timer.Reset();
     // Since Reset happened before task ran, the user_task must not be cleared:
     ASSERT_FALSE(timer.user_task().is_null());
     RunLoop().Run();
     EXPECT_TRUE(g_callback_happened1);
   }
 }
 
 }  // namespace base