[codex] extract Bazel build file parsing utility

[lukasoyen]

Summary

Extracts shared Bazel BUILD file parsing helpers into dev_tools.build_file_parsing_util.

This moves rule-call parsing and tag detection out of check_rule_has_tag.py, keeps the existing hook behavior unchanged, and adds dedicated utility tests.

Validation

• uv run --extra dev pytest tests/test_build_file_parsing_util.py tests/test_check_rule_has_tag.py
• uv run --with ruff ruff check dev_tools/build_file_parsing_util.py dev_tools/check_rule_has_tag.py tests/test_build_file_parsing_util.py tests/test_check_rule_has_tag.py
• uv run --with ruff ruff format --check dev_tools/build_file_parsing_util.py dev_tools/check_rule_has_tag.py tests/test_build_file_parsing_util.py tests/test_check_rule_has_tag.py
• uv run --with ty ty check dev_tools/build_file_parsing_util.py dev_tools/check_rule_has_tag.py tests/test_build_file_parsing_util.py tests/test_check_rule_has_tag.py

[hofbi]

Thanks for the cleanup. Could you split this up in 2 PRs. A first one where we extract the common logic + tests into the utils file and utils tests. We get that merged first. Then a second PR adding the new hook. This makes it easier to review.

[lukasoyen]

Done. I split this so PR #128 now only extracts the shared Bazel BUILD file parsing/tag helpers into dev_tools/build_file_parsing_util.py and adds dedicated utility tests. The new hook work is kept separately on a follow-up branch for a second PR after this one lands.

[lukasoyen]

Created the stacked follow-up PR for the new hook here: lukasoyen#1

It is based on the utility branch from this PR and contains only the forbidden-tag hook commit.

[hofbi]

Suggested change

	from dev_tools.build_file_parsing_util import find_rule_calls as find_build_file_rule_calls
	from dev_tools.build_file_parsing_util import find_rule_calls

[hofbi]

Oh now I get it, the impl slighly changed and we have the function still here. Can you explain?

[lukasoyen]

Previously the find_rule_calls() got the rule kind to inject into the regex. With the new helper function that is no longer the case as the forbidden tag use case needs to be able to glob on the rule kind.

So now the regex matches all targets and the function needs to filter down to the rule kinds it is interested in for check_rule_has_tag.py. Also the return type is enhanced because the forbidden tags use case needs to get the rule kind and the target body.

We want to have the filtering in the helper find_rule_calls() because we can do that before we try to do the expensive parenthesis matching.

[hofbi]

Since we are moving these two, we should also move their tests in https://github.com/hofbi/dev-tools/blob/master/tests/test_check_rule_has_tag.py instead of creating new ones.

[lukasoyen]

Done in 761899f: moved the parser/tag tests out of test_check_rule_has_tag.py so they now live in tests/test_build_file_parsing_util.py, and left test_check_rule_has_tag.py focused on the hook-level file checks.