public void AsManyAsBurstTokensAreAvailableRightAway(int burst)
{
// arrange
var clock = new FakeSystemClock();
var limiter = new Limiter(new Limit(10), burst, clock);
// act
var allowed = new List <bool>();
foreach (var index in Enumerable.Range(1, burst))
{
allowed.Add(limiter.Allow());
}
var notAllowed = limiter.Allow();
// assert
allowed.ShouldAllBe(item => item == true);
notAllowed.ShouldBeFalse();
}
public void FirstTokenIsAvailable()
{
// arrange
var clock = new FakeSystemClock();
var limiter = new Limiter(new Limit(10), 1, clock);
// act
var allowed = limiter.Allow();
// assert
allowed.ShouldBe(true);
}
public void TokensBecomeAvailableAtLimitPerSecondRate()
{
// arrange
var clock = new FakeSystemClock();
var limiter = new Limiter(new Limit(10), 50, clock);
// act
var initiallyAllowed = limiter.AllowN(clock.UtcNow, 50);
var thenNotAllowed1 = limiter.Allow();
clock.Advance(TimeSpan.FromMilliseconds(100));
var oneTokenAvailable = limiter.Allow();
var thenNotAllowed2 = limiter.Allow();
clock.Advance(TimeSpan.FromMilliseconds(200));
var twoTokensAvailable1 = limiter.Allow();
var twoTokensAvailable2 = limiter.Allow();
var thenNotAllowed3 = limiter.Allow();
// assert
initiallyAllowed.ShouldBeTrue();
thenNotAllowed1.ShouldBeFalse();
oneTokenAvailable.ShouldBeTrue();
thenNotAllowed2.ShouldBeFalse();
twoTokensAvailable1.ShouldBeTrue();
twoTokensAvailable2.ShouldBeTrue();
thenNotAllowed3.ShouldBeFalse();
}
public void ReserveTellsYouHowLongToWait()
{
// arrange
var clock = new FakeSystemClock();
var limiter = new Limiter(new Limit(10), 50, clock);
// act
var initiallyAllowed = limiter.AllowN(clock.UtcNow, 50);
var thenNotAllowed1 = limiter.Allow();
var reserveOne = limiter.Reserve();
var delayOne = reserveOne.Delay();
var reserveTwoMore = limiter.Reserve(clock.UtcNow, 2);
var delayTwoMore = reserveTwoMore.Delay();
clock.Advance(TimeSpan.FromMilliseconds(450));
var reserveAlreadyAvailable = limiter.Reserve();
var delayAlreadyAvailable = reserveAlreadyAvailable.Delay();
var reserveHalfAvailable = limiter.Reserve();
var delayHalfAvailable = reserveHalfAvailable.Delay();
// assert
initiallyAllowed.ShouldBeTrue();
thenNotAllowed1.ShouldBeFalse();
reserveOne.Ok.ShouldBeTrue();
delayOne.ShouldBe(TimeSpan.FromMilliseconds(100));
reserveTwoMore.Ok.ShouldBeTrue();
delayTwoMore.ShouldBe(TimeSpan.FromMilliseconds(300));
reserveAlreadyAvailable.Ok.ShouldBeTrue();
delayAlreadyAvailable.ShouldBe(TimeSpan.Zero);
reserveHalfAvailable.Ok.ShouldBeTrue();
delayHalfAvailable.ShouldBe(TimeSpan.FromMilliseconds(50));
}