Assertions for Func<Task<T>>

[jnyrup]

Currently both Func<Task> and Func<Task<T>> are handled by AsyncFunctionAssertions which has a Subject of type Func<Task> and hence ignores the return value for Func<Task<T>>.

If we split AsyncFunctionAssertions into:

• AsyncFunctionAssertions for Func<Task<T>>, and
• AsyncActionAssertions for Func<Task>

That should enable us to return the result of Task<T> for further assertions, similar to what was implement ed for Func<T> in #951, such as:

// Arrange/Act
Func<Task<int>> func = () => Task.FromResult(42);

// Assert
func.Should().NotThrow().Which.Should().Be(42);
(await func.Should().NotThrowAsync()).Which.Should().Be(42);

This was inspired by this question

[dennisdoomen]

Yeah, sounds like a good idea.

[lg2de]

I would like to combine this extension with an additional feature:

func.Should().Complete(TimeSpan.FromMilliseconds(100));

The test would fail if the Task does not complete within specified time span.

What do you think about such feature?

[dennisdoomen]

That's a nice idea, and a very useful one as well.

[lg2de]

While thinking about the implementation I would like to check whether my "Complete" extension should be based on Func<Task<T>> or maybe better on Task<T>.
The latter would result into easier usage:

this.myServer.OpenAsync().Should().Complete(TimeSpan.FromMilliseconds(100));

In this case my changes would not touch anymore the refactoring mentioned by @jnyrup.
Should I create another issue therefore before providing a pull request?

[jnyrup]

@lg2de I would prefer if you opened a new issue with an API proposal describing the purpose of the functions and their function signatures.