DEVX-63: feat: extract generic tools into devx, expand devx.mak, remove personal references

tests/unit/test_check_mutable_globals.py

@@ -0,0 +1,249 @@
+"""Unit tests for devx.tools.check_mutable_globals."""
+
+from pathlib import Path
+from unittest.mock import patch
+
+from click.testing import CliRunner
+
+from devx.tools.check_mutable_globals import (
+    DEFAULT_SCAN_DIRS,
+    DEFAULT_SKIP_DIRS,
+    _load_config,
+    _should_skip,
+    cli,
+    find_mutable_globals,
+)
+
+
+class TestFindMutableGlobals:
+    def test_detects_set_global_with_path_hint(self, tmp_path: Path) -> None:
+        source = "_SEEN: set[Path] = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+        assert "_SEEN" in issues[0]
+        assert "set()" in issues[0]
+
+    def test_detects_dict_global_with_path_hint(self, tmp_path: Path) -> None:
+        source = "_CACHE: dict[Path, Any] = {}\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+        assert "_CACHE" in issues[0]
+
+    def test_detects_list_global_with_path_hint(self, tmp_path: Path) -> None:
+        source = "PATHS: list[Path] = []\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+        assert "PATHS" in issues[0]
+
+    def test_skips_non_mutable_globals(self, tmp_path: Path) -> None:
+        source = "_MAX: int = 10\n_SEEN: set[Path] = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+        assert "_SEEN" in issues[0]
+
+    def test_skips_globals_without_path_hint(self, tmp_path: Path) -> None:
+        source = "_DATA: dict[str, int] = {}\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 0
+
+    def test_detects_path_type_annotation(self, tmp_path: Path) -> None:
+        source = "_FILES: set[Path] = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+
+    def test_known_safe_exception(self, tmp_path: Path) -> None:
+        source = "_SEEN: set[Path] = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        known_safe = {("mod.py", 1, "_SEEN")}
+        issues = find_mutable_globals(f, tmp_path, known_safe)
+        assert len(issues) == 0
+
+    def test_syntax_error_returns_empty(self, tmp_path: Path) -> None:
+        f = tmp_path / "mod.py"
+        f.write_text("def broken(:\n")
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert issues == []
+
+    def test_detects_mutable_literal_dict(self, tmp_path: Path) -> None:
+        source = "_CACHE: dict[Path, Any] = {}\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+
+    def test_detects_mutable_literal_list(self, tmp_path: Path) -> None:
+        source = "SEEN_PATHS: list[Path] = []\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+
+    def test_detects_mutable_literal_set(self, tmp_path: Path) -> None:
+        source = "REGISTRY: set[Path] = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+
+    def test_skips_function_definitions(self, tmp_path: Path) -> None:
+        source = "def foo():\n    pass\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert issues == []
+
+    def test_handles_assign_with_name_target(self, tmp_path: Path) -> None:
+        source = "SEEN_PATHS = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert len(issues) == 1
+        assert "SEEN_PATHS" in issues[0]
+
+    def test_skips_annotation_without_value(self, tmp_path: Path) -> None:
+        source = "_CACHE: dict[Path, Any]\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        assert issues == []
+
+    def test_skips_attribute_call(self, tmp_path: Path) -> None:
+        # collections.defaultdict is an Attribute call, not a Name call
+        source = "_CACHE: dict[Path, Any] = collections.defaultdict(list)\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        # Attribute calls are skipped (pass), so not flagged as mutable literal
+        assert issues == []
+
+    def test_multiple_assign_targets(self, tmp_path: Path) -> None:
+        source = "SEEN = CACHE = set()\n"
+        f = tmp_path / "mod.py"
+        f.write_text(source)
+        issues = find_mutable_globals(f, tmp_path, set())
+        # Both SEEN and CACHE should be flagged
+        assert len(issues) == 2
+
+
+class TestShouldSkip:
+    def test_skips_pycache(self) -> None:
+        assert _should_skip(Path("/a/__pycache__/b.py"), DEFAULT_SKIP_DIRS) is True
+
+    def test_skips_venv(self) -> None:
+        assert _should_skip(Path("/a/.venv/b.py"), DEFAULT_SKIP_DIRS) is True
+
+    def test_does_not_skip_normal(self) -> None:
+        assert _should_skip(Path("/a/src/b.py"), DEFAULT_SKIP_DIRS) is False
+
+
+class TestLoadConfig:
+    def test_defaults_when_no_pyproject(self, tmp_path: Path) -> None:
+        with patch("devx.tools.check_mutable_globals._load_pyproject_devx", return_value={}):
+            scan_dirs, skip_dirs, known_safe = _load_config()
+            assert scan_dirs == DEFAULT_SCAN_DIRS
+            assert skip_dirs == DEFAULT_SKIP_DIRS
+            assert known_safe == set()
+
+    def test_reads_config_from_pyproject(self) -> None:
+        cfg = {
+            "check_mutable_globals": {
+                "scan_dirs": ["src", "tests"],
+                "skip_dirs": ["__pycache__", ".tox"],
+                "known_safe": ["src/mod.py:10:_CACHE"],
+            }
+        }
+        with patch("devx.tools.check_mutable_globals._load_pyproject_devx", return_value=cfg):
+            scan_dirs, skip_dirs, known_safe = _load_config()
+            assert scan_dirs == ["src", "tests"]
+            assert ".tox" in skip_dirs
+            assert ("src/mod.py", 10, "_CACHE") in known_safe
+
+    def test_returns_defaults_when_cfg_not_dict(self) -> None:
+        with patch(
+            "devx.tools.check_mutable_globals._load_pyproject_devx",
+            return_value={"check_mutable_globals": "not a dict"},
+        ):
+            scan_dirs, skip_dirs, known_safe = _load_config()
+            assert scan_dirs == DEFAULT_SCAN_DIRS
+            assert skip_dirs == DEFAULT_SKIP_DIRS
+            assert known_safe == set()
+
+    def test_known_safe_with_invalid_line_number(self) -> None:
+        cfg = {"check_mutable_globals": {"known_safe": ["mod.py:abc:_CACHE"]}}
+        with patch("devx.tools.check_mutable_globals._load_pyproject_devx", return_value=cfg):
+            _, _, known_safe = _load_config()
+            assert known_safe == set()
+
+    def test_scan_dirs_not_list_returns_default(self) -> None:
+        cfg = {"check_mutable_globals": {"scan_dirs": "not a list"}}
+        with patch("devx.tools.check_mutable_globals._load_pyproject_devx", return_value=cfg):
+            scan_dirs, _, _ = _load_config()
+            assert scan_dirs == DEFAULT_SCAN_DIRS
+
+
+class TestCli:
+    def test_passes_when_no_issues(self, tmp_path: Path) -> None:
+        runner = CliRunner()
+        with (
+            patch("devx.tools.check_mutable_globals._load_config", return_value=(["empty_dir"], set(), set())),
+            patch("devx.tools.check_mutable_globals.Path.cwd", return_value=tmp_path),
+        ):
+            result = runner.invoke(cli, [])
+            assert result.exit_code == 0
+            assert "Passed" in result.output
+
+    def test_fails_when_issues_found(self, tmp_path: Path) -> None:
+        scan_dir = tmp_path / "src"
+        scan_dir.mkdir()
+        (scan_dir / "mod.py").write_text("_SEEN: set[Path] = set()\n")
+
+        runner = CliRunner()
+        with (
+            patch("devx.tools.check_mutable_globals._load_config", return_value=(["src"], set(), set())),
+            patch("devx.tools.check_mutable_globals.Path.cwd", return_value=tmp_path),
+        ):
+            result = runner.invoke(cli, [])
+            assert result.exit_code != 0
+            assert "FAILED" in result.output
+
+    def test_scan_dir_option_overrides_config(self, tmp_path: Path) -> None:
+        scan_dir = tmp_path / "custom"
+        scan_dir.mkdir()
+        (scan_dir / "mod.py").write_text("_SEEN: set[Path] = set()\n")
+
+        runner = CliRunner()
+        with (
+            patch("devx.tools.check_mutable_globals._load_config", return_value=(["other"], set(), set())),
+            patch("devx.tools.check_mutable_globals.Path.cwd", return_value=tmp_path),
+        ):
+            result = runner.invoke(cli, ["--scan-dir", "custom"])
+            assert result.exit_code != 0
+            assert "FAILED" in result.output
+
+    def test_skips_files_in_skip_dirs(self, tmp_path: Path) -> None:
+        scan_dir = tmp_path / "src"
+        pycache = scan_dir / "__pycache__"
+        pycache.mkdir(parents=True)
+        (pycache / "mod.py").write_text("_SEEN: set[Path] = set()\n")
+
+        runner = CliRunner()
+        with (
+            patch("devx.tools.check_mutable_globals._load_config", return_value=(["src"], {"__pycache__"}, set())),
+            patch("devx.tools.check_mutable_globals.Path.cwd", return_value=tmp_path),
+        ):
+            result = runner.invoke(cli, [])
+            assert result.exit_code == 0
+            assert "Passed" in result.output