rx.md

Rx

The IAsyncEnumerable provides a possible infinite stream of data. In order to validate if all items match or to fail an any items matches when none do you need to introduce a time constraint to indicate an end to the stream.

var observer = Observer.For<string>();
await observer.Add("a");

var result = await observer
    .Timebox(5.Seconds())
    .AllAsync(x => x == "a"); // <-- from: System.Linq.Async

result
    .Should()
    .BeTrue(); // <-- from: FluentAssertions

Here .Timebox(TimeSpan) from Hypothesist is used to introduce the time constraint in the (hypothetical) infinite stream of data. This method combined both the .WithTimeout(TimeSpan) with .UntilCancelled() from this library.

Although this approach works fine, you lack the context you are used to when using FluentAssertions. That additional context of items that didn't match is provided when using the Hypothesis.On() for validation.