Testing: assertions on a Task or ValueTask of an Option, a Result and a Patch #87

CodoMetis.TypeKit.Testing asserts on an Option, a Result, a Patch and a composed fault, but only when the test already holds the value. A test of an async method writes (await service.Find(id)).ShouldBeSuccess(). The roadmap's 2.3.0 section lists async assertions.

Proposal

The assertions on a Task<…> and a ValueTask<…> of each: await service.Find(id).ShouldBeSuccess(), ShouldBeError(…), ShouldBeSome(), ShouldBeNone(), and the Patch ones, returning what the synchronous form returns. Messages as the synchronous forms write them.

Done when

• Every synchronous assertion has its Task and ValueTask form, checked by a completeness test over the public surface.

• A faulted task's exception propagates as it is, not wrapped in an assertion failure.

• The Testing README shows them as compiled samples.

• An assertion on a task left without await is reported (CMTK0003). Without await it passes whatever the task holds, and C# warns only in an async method. The rule knows the assertions by the Testing assembly's identity, so a consumer's own extension on a pending result is not reported, and no build that worked before 2.3 breaks. (Scope added while implementing.)