dennisdoomen/fluentassertions — pull request #143 by BrunoJuchli (2014-07-29 16:09:03+00:00)
Title: `Invoke(...)` extension method for async await (named `Awaiting(..)`)

added Awaiting(async x => await x...) Extension as an "async await" counterpart.

usage:
foo
.Awaiting(async x => await x.DoSomething())
.ShouldThrow();