fix: move clang tools dependencies to optional

cpp_linter_hooks/util.py

@@ -20,6 +20,14 @@ def get_version_from_dependency(tool: str) -> Optional[str]:
         return None
     with open(pyproject_path, "rb") as f:
         data = tomllib.load(f)
+    # First try project.optional-dependencies.tools
+    optional_deps = data.get("project", {}).get("optional-dependencies", {})
+    tools_deps = optional_deps.get("tools", [])
+    for dep in tools_deps:
+        if dep.startswith(f"{tool}=="):
+            return dep.split("==")[1]
+
+    # Fallback to project.dependencies for backward compatibility
     dependencies = data.get("project", {}).get("dependencies", [])
     for dep in dependencies:
         if dep.startswith(f"{tool}=="):
@@ -176,6 +184,14 @@ def _resolve_install(tool: str, version: Optional[str]) -> Optional[Path]:
             else DEFAULT_CLANG_TIDY_VERSION
         )
 
+    # Additional safety check in case DEFAULT versions are None
+    if user_version is None:
+        user_version = (
+            DEFAULT_CLANG_FORMAT_VERSION
+            if tool == "clang-format"
+            else DEFAULT_CLANG_TIDY_VERSION
+        )
+
     path = shutil.which(tool)
     if path:
         runtime_version = _get_runtime_version(tool)

pyproject.toml

@@ -32,9 +32,8 @@ classifiers = [
     "Topic :: Software Development :: Build Tools",
 ]
 dependencies = [
-    "clang-format==20.1.7",
-    "clang-tidy==20.1.0",
     "tomli>=1.1.0; python_version < '3.11'",
+    "setuptools>=45.0.0", # Required for pkg_resources in clang-tidy
 ]
 dynamic = ["version"]
 
@@ -47,6 +46,12 @@ source =  "https://github.com/cpp-linter/cpp-linter-hooks"
 tracker = "https://github.com/cpp-linter/cpp-linter-hooks/issues"
 
 [project.optional-dependencies]
+# only clang tools can added to this section to make hooks work
+tools = [
+    "clang-format==20.1.7",
+    "clang-tidy==20.1.0",
+]
+
 dev = [
     "coverage",
     "pre-commit",

tests/test_util.py

@@ -102,11 +102,13 @@ def test_get_version_from_dependency_success():
     """Test get_version_from_dependency with valid pyproject.toml."""
     mock_toml_content = {
         "project": {
-            "dependencies": [
-                "clang-format==20.1.7",
-                "clang-tidy==20.1.0",
-                "other-package==1.0.0",
-            ]
+            "optional-dependencies": {
+                "tools": [
+                    "clang-format==20.1.7",
+                    "clang-tidy==20.1.0",
+                    "other-package==1.0.0",
+                ]
+            }
         }
     }
 
@@ -132,7 +134,9 @@ def test_get_version_from_dependency_missing_file():
 @pytest.mark.benchmark
 def test_get_version_from_dependency_missing_dependency():
     """Test get_version_from_dependency with missing dependency."""
-    mock_toml_content = {"project": {"dependencies": ["other-package==1.0.0"]}}
+    mock_toml_content = {
+        "project": {"optional-dependencies": {"tools": ["other-package==1.0.0"]}}
+    }
 
     with (
         patch("pathlib.Path.exists", return_value=True),
@@ -423,3 +427,22 @@ def test_version_lists_not_empty():
     assert len(CLANG_TIDY_VERSIONS) > 0
     assert all(isinstance(v, str) for v in CLANG_FORMAT_VERSIONS)
     assert all(isinstance(v, str) for v in CLANG_TIDY_VERSIONS)
+
+
+@pytest.mark.benchmark
+def test_resolve_install_with_none_default_version():
+    """Test _resolve_install when DEFAULT versions are None."""
+    with (
+        patch("shutil.which", return_value=None),
+        patch("cpp_linter_hooks.util.DEFAULT_CLANG_FORMAT_VERSION", None),
+        patch("cpp_linter_hooks.util.DEFAULT_CLANG_TIDY_VERSION", None),
+        patch(
+            "cpp_linter_hooks.util._install_tool",
+            return_value=Path("/usr/bin/clang-format"),
+        ) as mock_install,
+    ):
+        result = _resolve_install("clang-format", None)
+        assert result == Path("/usr/bin/clang-format")
+
+        # Should fallback to hardcoded version when DEFAULT is None
+        mock_install.assert_called_once_with("clang-format", None)