fix: hide pre-commit checks if lefthook is used (#702)

Signed-off-by: Henry Schreiner <henryfs@princeton.edu>

Author: henryiii

pyproject.toml

@@ -159,6 +159,10 @@ messages_control.disable = [
 ]
 
 
+[tool.ruff]
+show-fixes = true
+extend-exclude = ["\\{\\{cookiecutter.project_name\\}\\}"]
+
 [tool.ruff.lint]
 extend-select = [
   "ARG",    # flake8-unused-arguments

src/sp_repo_review/checks/precommit.py

@@ -245,5 +245,14 @@ def check(precommit: dict[str, Any]) -> bool:
         return "autoupdate_schedule" in precommit.get("ci", {})
 
 
-def repo_review_checks() -> dict[str, PreCommit]:
+def repo_review_checks(
+    list_all: bool = True,
+    root: Traversable | None = None,
+) -> dict[str, PreCommit]:
+    if root and not list_all:
+        precommit_path = root.joinpath(".pre-commit-config.yaml")
+        lefthook_path = root.joinpath("lefthook.yml")
+        if not precommit_path.is_file() and lefthook_path.is_file():
+            return {}
+
     return {p.__name__: p() for p in PreCommit.__subclasses__()}

tests/test_precommit.py

@@ -1,7 +1,11 @@
+from pathlib import Path
+
 import pytest
 import yaml
 from repo_review.testing import compute_check
 
+from sp_repo_review.checks.precommit import repo_review_checks
+
 
 @pytest.fixture(params=["ruff", "ruff-check"])
 def ruff_check(request: pytest.FixtureRequest) -> str:
@@ -283,3 +287,17 @@ def test_pc903_no_msg():
     res = compute_check("PC903", precommit=precommit)
     assert not res.result
     assert "autoupdate_schedule" in res.err_msg
+
+
+def test_repo_review_checks_skips_with_lefthook_only(tmp_path: Path) -> None:
+    """PreCommit checks should be omitted if only lefthook.yml is present.
+
+    When a repository uses `lefthook.yml` and does not have a
+    `.pre-commit-config.yaml`, `repo_review_checks` should return an empty
+    mapping when `list_all=False` indicating the pre-commit family is skipped.
+    """
+    # Create only a lefthook configuration
+    (tmp_path / "lefthook.yml").write_text("hooks:\n", encoding="utf-8")
+
+    checks = repo_review_checks(list_all=False, root=tmp_path)
+    assert checks == {}