How to represent a matrix of test targets?

[sluongng]

I am working on neotest-bazel and our test hierarchy is a bit different than a typical file-based setup.

Each Bazel's package (directory) could contain multiple test targets.
Each target could be using different files to group up a test, or the same files but with different parameters.

So what does this translate to is that an example setup like this is possible:

• Given a package //foo and 2 test targets //foo:bar and //foo:baz.
• Both //foo:bar and //foo:baz use source file //foo:foo_test.go, but build and run it with different flags.
• Inside foo_test.go, there could be multiple tests: TestA, TestB and sub-tests TestC/with_X, TestC/with_Y.

What is unclear to me is how to tell Neotest about :bar and :baz?

Initially, I thought that I could modify build_position to return multiple neotest.Position[], each with the same test but with an added target prefix to name. But that did not work at all.

Do I have to construct a parent tree in discover_positions for bar and baz? 🤔

[sluongng]

I looked into this a bit more and I think the current way neotest is doing this is to walk the file tree downward. It would be nice to get a hook/api into neotest to customize the tree walk. That way, I can use Bazel query to discover the test targets instead of having to walk the file tree with neotest.