public void AdvancesWithVirtualTime()
{
// Arrange
var clock = new VirtualClock(new DateTimeOffset(2010, 01, 01, 01, 01, 01, TimeSpan.Zero));
// Act
clock.Advance(TimeSpan.FromDays(10));
// Assert
Assert.Equal(new DateTimeOffset(2010, 01, 11, 01, 01, 01, TimeSpan.Zero), clock.UtcNow);
}
public void DelayWaitsForVirtualTimeToElapse()
{
// Arrange
var clock = new VirtualClock(new DateTimeOffset(2010, 01, 01, 01, 01, 01, TimeSpan.Zero));
var task = clock.Delay(TimeSpan.FromMilliseconds(1));
// Assume - Task has not completed
Assert.False(task.IsCompleted);
// Act
clock.Advance(TimeSpan.FromSeconds(1));
// Assert
Assert.True(task.IsCompleted);
}
public async Task DoesNotAdvanceWithRealTime()
{
// Arrange
var testStart = DateTimeOffset.UtcNow;
var clock = new VirtualClock(testStart);
var captured = clock.UtcNow;
// Act
// Use real Task.Delay because we need to sleep for real time
await Task.Delay(TimeSpan.FromMilliseconds(10));
// Assert
Assert.Equal(captured, clock.UtcNow);
Assert.True(DateTimeOffset.UtcNow >= clock.UtcNow);
}
public void ReturnsCurrentTimeAsUtcNowIfNoStartTimeProvided()
{
var testStart = DateTimeOffset.UtcNow;
var clock = new VirtualClock();
Assert.True(clock.UtcNow >= testStart);
}