.HandleResult() does not throw an exception when all retries fail

[pehrn]

Hi,

I have a TryAndRetry function where I Retry if result != expectedResult, however when it reaches max retries, my tests pass and no exception is thrown from .HandleResult(). Could anyone help?

[martincostello]

Please provide some code that demonstrates the issue.

[peter-csala]

Based on your really vague description it is hard to provide any valuable suggestions.
As Martin indicated if you could provide a code sample that would help a lot to resolve your issue.

---

BUT let me try to assist you by making an assumption: You have a policy definition which triggers only if the decorated method does not return the expected value.

For the sake of simplicity lets assume the definition looks something like this:

var retry = Policy
    .HandleResult<int>(result => result != expectedResult)
    .Retry(2);

then all you need to do is to capture the result of the Execute and make an assertion against it.

Something like this

[Fact]
public void Test1()
{
    //Arrange
    const int expectedResult = 42;
    var retry = Policy
      .HandleResult<int>(result => result != expectedResult)
      .Retry(2);

    //Act
    var actualResult = retry.Execute(() => 41);

    //Assert
    Assert.Equal(expectedResult, actualResult);
}

[pehrn]

Hello & sorry for the late reply.

Actually, your example is pretty much what I am doing. I wanted to remove the final Assert.That() statement and instead just let the var actualResult = retry.Execute(() => 41) throw the exception, however nothing happens, but it probably doesn't work like that - I am still working on my c# skills. I assume Assert statement is necessary, then. Thank you

[peter-csala]

Hello Peter,

If your decorated method does not throw exception then a retry policy will not throw either.
In other cases like timeout, the policy itself throws a TimeoutRejectedException if the execution did not finish on time.

The retry.Execute will throw exception only if your decorated method throws exception and you run out of retry attempts. This is depicted on this diagram: https://github.com/App-vNext/Polly/wiki/Retry#how-polly-retry-works

So, the Assert.XYZ is needed to perform an assessment on the actual and expected values.
If they mismatch then it will throw an exception which will cause the unit test to fail.