[Documentation] MSTest documentation lacks information about test lifecycle

[Youssef1313]

Information about lifecycle doesn't seem to be documented. I think it can be summarized as follows.

• AssemblyInitialize is called, if present
• For every class:
  • ClassInitialize is called, if present.
  • For every test case in the class (a parameterized test method has its individual inputs as separate test cases):
    • Create class instance (so your constructor is called, optionally, it can have TestContext parameter)
    • Set TestContext property if present
    • Run TestInitialize, including from base classes (base classes are called first in reverse order, then TestInitialize from the current class)
    • Run the test method itself. If it returns a Task/ValueTask, we await it
    • Update the test outcome in TestContext
    • Run TestCleanup methods. First we run TestCleanup from the current class, then from any base classes in order (so it's reverse order of test initialize)
    • If you implement IAsyncDisposable, we call DisposeAsync
    • If you implement IDisposable, we call Dispose
  • ClassCleanup is called, if present.
• AssemblyCleanup is called, if present.

[marcelwgn]

I would like to work on this.

[Evangelink]

Awesome thanks for willing to help @marcelwgn! I think we can create a new page under Writing test and we probably want to link this attribute section https://learn.microsoft.com/dotnet/core/testing/unit-testing-mstest-writing-tests-attributes#attributes-used-to-provide-initialization-and-cleanups

[hawkerm]

Yeah, this has definitely been confusing in the current docs. Clarification in the notes on what "The properties related to the test run are not available" (or what that includes) would be useful too.

I followed the new 3.6+ example for TestContext setting in the constructor, but either way, I'm adding a property to the context in the Properties bag, in the static ClassInitialize method. However, only one of my two test methods can access it, randomly. It looks like two class instances for each or my tests is created, as described above, but one of them gets passed a general TestContext, instead of the one passed in and modified by ClassInitialize. To me it seems like the same root TestContext passed to ClassInitialize should be used for all tests?

Does TestContext itself need more clarification above too? Am I misunderstanding how this works, or is this a bug where the context isn't propagating properly?

[marcelwgn]

Ive created the PR for this page here: dotnet/docs#46540

[Youssef1313]

Docs PR is merged.