public void TracksBucketOverflow()
{
TimeService.CurrentDateTime.Returns(baseTime);
var bucket = new LeakyBucket(TimeService, AnalyticsService, 1);
bucket.TryClaimFreeSlot(out _);
bucket.TryClaimFreeSlots(1, out _);
AnalyticsService.Received().LeakyBucketOverflow.Track();
}
public void AllowsSlotsInAShortPeriodOfTimeUntilReachingTheLimit(int slotsPerWindow)
{
TimeService.CurrentDateTime.Returns(baseTime);
var client = new LeakyBucket(TimeService, AnalyticsService, slotsPerWindow);
var claimed = client.TryClaimFreeSlots(slotsPerWindow, out var timeToNextFreeSlot);
claimed.Should().BeTrue();
timeToNextFreeSlot.Should().Be(TimeSpan.Zero);
}
public void ReturnsNonZeroTimeToNextSlotTooManyRequestsAreSentInAShortPeriodOfTime(int slotsPerWindow)
{
TimeService.CurrentDateTime.Returns(baseTime);
var bucket = new LeakyBucket(TimeService, AnalyticsService, slotsPerWindow);
bucket.TryClaimFreeSlots(slotsPerWindow, out _);
var claimed = bucket.TryClaimFreeSlot(out var time);
claimed.Should().BeFalse();
time.Should().BeGreaterThan(TimeSpan.Zero);
}
public void ReturnsNonZeroTimeToNextSlotWhenTooManySlotsAreUsedInAShortPeriodOfTime(int slotsPerWindowLimit)
{
timeService.CurrentDateTime.Returns(baseTime);
var bucket = new LeakyBucket(timeService, slotsPerWindowLimit);
bucket.TryClaimFreeSlot(out _);
var claimed = bucket.TryClaimFreeSlots(slotsPerWindowLimit, out var time);
claimed.Should().BeFalse();
time.Should().BeGreaterThan(TimeSpan.Zero);
}
public void ThrowsWhenTooManySlotsAreRequested(PositiveInt slotsPerWindow)
{
if (slotsPerWindow.Get == int.MaxValue)
{
return;
}
TimeService.CurrentDateTime.Returns(baseTime);
var bucket = new LeakyBucket(TimeService, AnalyticsService, slotsPerWindow.Get);
Action claimMany = () => bucket.TryClaimFreeSlots(slotsPerWindow.Get + 1, out _);
claimMany.Should().Throw <InvalidOperationException>();
}
public void CalculatesTheDelayUntilNextFreeSlot()
{
TimeService.CurrentDateTime.Returns(
baseTime,
baseTime + TimeSpan.FromSeconds(
3),
baseTime + TimeSpan.FromSeconds(6),
baseTime + TimeSpan.FromSeconds(8));
var bucket = new LeakyBucket(TimeService, AnalyticsService, slotsPerWindow: 4, movingWindowSize: TimeSpan.FromSeconds(10));
bucket.TryClaimFreeSlot(out _);
bucket.TryClaimFreeSlot(out _);
bucket.TryClaimFreeSlot(out _);
var claimed = bucket.TryClaimFreeSlots(3, out var timeToFreeSlot);
claimed.Should().BeFalse();
timeToFreeSlot.Should().Be(TimeSpan.FromSeconds(5));
}
