[FR]: How to integrate custom test rules with configure

[antspy]

What is the current behavior?

Hi,

I am using rules_ts with bazel, and by default it will create a ts_project rule for each .ts file found in a directory. The same applies to test files ending in .spec.ts..

This behavior can be modified to a limited extent using gazelle directives, but I don't see a way to get the behavior I want.

Describe the feature

I have a custom rule I want to use for tests. Nothing special, but it combines a ts_project for the test file with a vitest run from load("@npm//:vitest/package_json.bzl", vitest_bin = "bin").

So the idea is that I would be able to write

ts_test(
    name = 'mytest', 
    srcs = ['my.test.ts'],
    deps = [...], 
)

and that's all. I don't see how to get the behavior I want though.

1. I cannot use a simple aspect:map_kind directive, because I want the substitution ts_project -> ts_test to happen only for test files, not for every filetype (other ts files should still use the ts_project rule).
2. I looked into the Starlark Extension API (which seems really cool!) but I have found 2 issues:
   • The first is that the default ts_project behavior is not changes, so now I have both a ts_test rule and a ts_project rule, which is not what I want
   • The second is that I would have to write my own logic for ts_test dependencies. Here I just want to reuse the same logic from ts_project, just set in a different macro - but I don't want to rewrite the whole 'parse file import to add dependencies' logic.

So my question is - what can I do about this? I am very new to this space, so perhaps there's something obvious I am missing.
One thing that I think might work is to add a gazelle directive to specify which rule should be used for the .spec.ts targets, so that I could set it to my own rule using the aspect:map_kind directive and have everything else work as it is, without having to write a custom starlark plugin

Another idea would be exporting the whole logic as a starlark extension so one could change it without having to fork / recompile the CLI, but directly adding a new plugin.

Any help would be appreciated. Thanks a lot!