Allow callbacks (Do/Does) before Returns

[Jason31569]

Referencing issue #98...

While doing something like stuffDoer.Calculate().Returns(42).AndCalls(x => blah()); works, it is would make a lot more sense to be able to do something like stuffDoer.Calculate(something).Do(x => { }).Returns(42); instead

Take the below example

var items = new List<int> { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };

var a = items.Where(x => x % 2 == 0).Skip(3).ToArray();
var b = items.Skip(3).Where(x => x % 2 == 0).ToArray();

Because execution is from left to right a=[8, 10], and b=[4, 6, 8, 10]

We are used to reading (and even expecting) statements to work from left to right. Someone new to NSubstitute (like myself) could find this confusing, and would not expect the trailing Do to run before the Returns

[dtchepak]

Agree it reads better, but the trade-off is that we're adding yet another extension method on object (bloats intellisense/autocomplete). We could potentially have in NSubstitute.Extensions so people could opt-in 🤔 .

Another option is to use the existing .Returns overload with a call back to "do and return".

[Jason31569]

Agree it reads better, but the trade-off is that we're adding yet another extension method on object (bloats intellisense/autocomplete). We could potentially have in NSubstitute.Extensions so people could opt-in 🤔 .

Maybe the NSubstitute.Extensions option is the way to go

Another option is to use the existing .Returns overload with a call back to "do and return".

Are you talking about one of these methods?

ConfiguredCall Returns<T>(this T value, Func<CallInfo, T> returnThis, params Func<CallInfo, T>[] returnThese)

ConfiguredCall Returns<T>(this Task<T> value, Func<CallInfo, T> returnThis, params Func<CallInfo, T>[] returnThese)

ConfiguredCall Returns<T>(this ValueTask<T> value, Func<CallInfo, T> returnThis, params Func<CallInfo, T>[] returnThese)

[dtchepak]

Yes those Returns overloads take Funcs which let us do then return.