public async Task ExceptionHandlersIncrementBackoff()
{
var backoffStrategy = Backoff
.LinearlyFrom(TimeSpan.FromMilliseconds(250));
int failureCount = 0;
var resilientOperation =
ResilientOperation.From(() =>
{
// Fail 3 times before succeeding
if (failureCount < 3)
{
failureCount++;
throw new Exception();
}
if (failureCount < 4)
{
failureCount++;
return(Task.FromResult(5));
}
return(Task.FromResult(42));
})
.WhenExceptionIs <Exception>(async(op, ex) =>
{
if (op.CurrentAttempt <= 3)
{
await op.RetryAfterAsync(backoffStrategy.Next());
}
})
.WhenResult(value => value != 42, async(op, value) =>
{
if (op.CurrentAttempt <= 4)
{
await op.RetryAfterAsync(backoffStrategy.Next());
}
})
.WhenResult(value => value == 42, (op, ex) =>
{
op.Return(0);
return(Task.CompletedTask);
})
.GetOperation();
Assert.Equal(0, await resilientOperation(CancellationToken.None));
Assert.Equal(4, failureCount);
Assert.Equal(TimeSpan.FromMilliseconds(250 * 5), backoffStrategy.Next());
}