Automatic cancellation support

I have a lot of dependencies with (usually async) methods that accept a CancellationToken. When the token is cancelled, these methods throw an OperationCanceledException. This is the expected implicit behavior for these methods, but by default, fakes don’t throw anything when they receive a call with a cancelled token. So my thinking is that this behavior could be baked into FakeItEasy as a default rule. Currently I use a method like this:

private static void ConfigureCancellation(object obj)
{
    A.CallTo(obj)
        .WhenArgumentsMatch(args => args.OfType<CancellationToken>().Any(ct => ct.IsCancellationRequested))
        .Invokes(call => call.Arguments.OfType<CancellationToken>().FirstOrDefault(ct => ct.IsCancellationRequested).ThrowIfCancellationRequested());
}

It works fine, but I have to remember to call it on each fake.

Note that enabling this by default would, technically, be a breaking change, although probably not one that would affect many users.

[adamralph]

I’m fine with it being part of 3.0.0.

There’s no firm definition of the phases, but the way I see it is:

• alpha: anything may change before RTM and probably will.
• beta: things may still change before RTM but they probably won’t.
• RC: RTM quality. Will be the RTM if no bugs are found. The only changes before RTM will be bug fixes and they will generate a new RC each time.

I think beta is the “grey zone” and is the tough one to call. Alpha and RC are relatively easy. I think it’s reasonable to call beta if nothing more is planned to change at that time the beta is released, and this is what we did in this case.

[adamralph]

I’m fine with leaving it open if we still want to explore other ways of doing it.