Report which Pester.BeforeContainer.ps1 files applied to a container

[nohwnd]

Fix #3007

Based on #3023, not on main. It needs the discovery-only path to receive the map, otherwise Run.SkipRun would report an empty list. Retarget to main once #3023 merges.

A container's setup comes from every Pester.BeforeContainer.ps1 between Run.RepoRoot and the test file's own folder, and nothing in the result said which ones were used. Opening tests/unit/Foo.Tests.ps1 shows no BeforeAll and gives no sign that two folder setups ran before it. Reading the directory tree does not answer it either, because #pester:no-inherit can cut the chain short.

The applied files are on the container now, outermost first, in the order they ran:

U.Tests.ps1:
    <root>/Pester.BeforeContainer.ps1
    <root>/tests/Pester.BeforeContainer.ps1
    <root>/tests/unit/Pester.BeforeContainer.ps1
D.Tests.ps1:
    <root>/tests/docs/Pester.BeforeContainer.ps1

D.Tests.ps1 sits under a folder marked #pester:no-inherit, so it reports only its own file. That is the case the folder tree cannot tell you.

On the container rather than the block, as the issue suggested. It is a property of the file being run, post-processors already walk containers, and it leaves the block model unchanged.

Verification

tst/Pester.RSpec.Parallel.ts.ps1 47/47, tst/Pester.RSpec.ts.ps1 128/128.

Two tests added next to the other cascade tests, one for the full chain and one for the #pester:no-inherit truncation.

I checked that Remove-RSpecNonPublicProperties does not drop the new property. Its property lists are commented out, it only nulls the plugin fields, so the property survives to PassThru.

🤖