public void GivenCircuitBreaker_WhenNew_ThenClose()
{
// Arrange & Act
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(5, TimeSpan.FromMinutes(5));
// Assert
Assert.True(circuitBreaker.IsClosed);
}
public void GivenCircuitBreaker_WhenFailure_ThenLastExceptionIsKept()
{
// Arrange
Action protectedCode = () => { throw new Exception("Message"); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(10, TimeSpan.FromMinutes(5));
// Act
circuitBreaker.AttemptCall(protectedCode);
// Assert
Assert.Equal("Message", circuitBreaker.GetExceptionFromLastAttemptCall().Message);
}
public void GivenCircuitBreaker_WhenFailure_ThenFailureCountIncrease()
{
// Arrange
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(10, TimeSpan.FromMinutes(5));
// Act
circuitBreaker.AttemptCall(protectedCode);
// Assert
Assert.Equal(1, circuitBreaker.Failures);
}
public void GivenCircuitBreaker_WhenAttemptCallCallOnCloseCircuit_ThenFailureCountRemainToZero()
{
// Arrange
Action protectedCode = () => { return; };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(10, TimeSpan.FromMinutes(5));
// Act
circuitBreaker.AttemptCall(protectedCode);
// Assert
Assert.Equal(0, circuitBreaker.Failures);
}
public void GivenCircuitBreaker_WhenAttemptCallCallOnCloseCircuit_ThenCallMethod()
{
// Arrange
bool protectedCodeWasCalled = false;
Action protectedCode = () => protectedCodeWasCalled = true;
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(10, TimeSpan.FromMinutes(5));
// Act
circuitBreaker.AttemptCall(protectedCode);
// Assert
Assert.True(protectedCodeWasCalled);
}
public void GivenCircuitBreakerClose_WhenThresholdIsReached_ThenOpen()
{
// Arrange
const int THRESHOLD = 10;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMinutes(5));
// Act
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
// Assert
Assert.True(circuitBreaker.IsOpen);
}
public void GivenCircuitBreakerClose_WhenManuallyOpen_ThenOpen()
{
// Arrange
const int THRESHOLD = 2;
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMinutes(5));
Assert.True(circuitBreaker.IsClosed);
// Act
circuitBreaker.Open();
// Assert
Assert.True(circuitBreaker.IsOpen);
}
public void GivenCircuitBreakerOpen_WhenTimeIfPassed_ThenHalfOpen()
{
// Arrange
const int THRESHOLD = 2;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMilliseconds(10));
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
// Act
Thread.Sleep(25);
// Assert
Assert.True(circuitBreaker.IsHalfOpen);
}
public void GivenCircuitBreakerClose_WhenOpenAndStateChangeSubscribed_ThenCallEventStateChangeOnce()
{
// Arrange
int changeStateCount = 0;
const int THRESHOLD = 2;
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMinutes(5));
circuitBreaker.OnStateChange += (o, state) => { changeStateCount++; };
Assert.True(circuitBreaker.IsClosed);
// Act
circuitBreaker.Open();
// Assert
Assert.Equal(1, changeStateCount);
}
public void GivenCircuitBreakerOpen_WhenManuallyClose_ThenClosed()
{
// Arrange
const int THRESHOLD = 2;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMinutes(5));
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
Assert.True(circuitBreaker.IsOpen);
// Act
circuitBreaker.Close();
// Assert
Assert.True(circuitBreaker.IsClosed);
}
public void GivenCircuitBreakerHalfOpen_WhenNoException_ThenFailureCountZero()
{
// Arrange
const int THRESHOLD = 2;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMilliseconds(10));
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
Thread.Sleep(25); //This set is back to HalfOpen
Assert.True(circuitBreaker.IsHalfOpen);
// Act
circuitBreaker.AttemptCall(() => { });
// Act
Assert.Equal(0, circuitBreaker.Failures);
}
public void GivenCircuitBreakerClose_WhenOpenTwiceAndStateChangeSubscribed_ThenCallEventStateChangeOnce()
{
// Arrange
int changeStateCount = 0;
const int THRESHOLD = 2;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMinutes(5));
circuitBreaker.OnStateChange += (o, state) => { changeStateCount++; };
Assert.True(circuitBreaker.IsClosed);
// Act
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
// Assert
Assert.Equal(1, changeStateCount);
}
public void GivenCircuitBreakerClose_WhenOpenAndCloseAndStateChangeSubscribed_ThenCallEventStateChangeTwice()
{
// Arrange
int changeStateCount = 0;
const int THRESHOLD = 2;
Action protectedCode = () => { throw new Exception(); };
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD, TimeSpan.FromMilliseconds(10));
circuitBreaker.OnStateChange += (o, state) => { changeStateCount++; };
Assert.True(circuitBreaker.IsClosed);
// Act
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD);
Thread.Sleep(25); //This set is back to HalfOpen
circuitBreaker.AttemptCall(() => { });
// Assert
Assert.Equal(3, changeStateCount); //Close->Open, Open->Half, Half->Close
}
public void GivenCircuitBreakerOpen_WhenCallAgain_ThenNotCallNotExecuted()
{
// Arrange
const int THRESHOLD_INVOCATION = 10;
int countInvocation = 0;
Action protectedCode = () =>
{
countInvocation++;
throw new Exception();
};
var circuitBreaker = new BaseCircuitBreaker.CircuitBreaker(THRESHOLD_INVOCATION, TimeSpan.FromMinutes(5));
CallXAmountOfTimes(() => circuitBreaker.AttemptCall(protectedCode), THRESHOLD_INVOCATION);
// Act
Assert.Equal(THRESHOLD_INVOCATION, countInvocation);
circuitBreaker.AttemptCall(protectedCode);
// Assert
Assert.Equal(THRESHOLD_INVOCATION, countInvocation);
}
