ENH: check contents of .constraints directory (#305)

* MAINT: use `CONFIG_PATH` for constraints directory name

src/compwa_policy/check_dev_files/precommit.py

@@ -19,6 +19,7 @@
     load_precommit_config,
     load_roundtrip_precommit_config,
 )
+from compwa_policy.utilities.project_info import get_supported_python_versions
 from compwa_policy.utilities.yaml import create_prettier_round_trip_yaml
 
 
@@ -77,7 +78,7 @@ def _update_precommit_ci_commit_msg() -> None:
     precommit_ci = config.get("ci")
     if precommit_ci is None:
         return
-    if CONFIG_PATH.pip_constraints.exists():
+    if __has_constraint_files():
         expected_msg = "MAINT: update pip constraints and pre-commit"
     else:
         expected_msg = "MAINT: autoupdate pre-commit hooks"
@@ -90,6 +91,13 @@ def _update_precommit_ci_commit_msg() -> None:
         raise PrecommitError(msg)
 
 
+def __has_constraint_files() -> bool:
+    python_versions = get_supported_python_versions()
+    return any(
+        (CONFIG_PATH.pip_constraints / f"py{v}.txt").exists() for v in python_versions
+    )
+
+
 def _update_precommit_ci_skip() -> None:
     config, yaml = load_roundtrip_precommit_config()
     precommit_ci = config.get("ci")

src/compwa_policy/utilities/project_info.py

@@ -4,7 +4,6 @@
 
 import os
 import sys
-from pathlib import Path
 from textwrap import dedent
 from typing import TYPE_CHECKING
 
@@ -18,6 +17,7 @@
 
 if TYPE_CHECKING:
     from configparser import ConfigParser
+    from pathlib import Path
 
     from tomlkit import TOMLDocument
 
@@ -172,7 +172,7 @@ def open_setup_cfg() -> ConfigParser:
 
 
 def get_constraints_file(python_version: PythonVersion) -> Path | None:
-    path = Path(f".constraints/py{python_version}.txt")
+    path = CONFIG_PATH.pip_constraints / f"py{python_version}.txt"
     if path.exists():
         return path
     return None