feat(config): add strict_config option to reject unknown config keys

Add a `strict_config` boolean option (default: false). When enabled,
commitizen raises InvalidConfigurationError if any key in the config
file is not a recognised Settings field. This catches typos early
instead of silently ignoring them.

- Add `strict_config` to the Settings TypedDict and DEFAULT_SETTINGS
- Add `_VALID_CONFIG_KEYS` in base_config derived from Settings.__annotations__
- Validate unknown keys in BaseConfig.update() when strict_config=True
- Route all _parse_setting calls through self.update() so validation runs
- Add tests covering TOML, JSON, YAML parsers and edge cases

Closes #300

Author: Prayasvadlakonda

commitizen/config/base_config.py

@@ -4,6 +4,7 @@
 from typing import TYPE_CHECKING
 
 from commitizen.defaults import DEFAULT_SETTINGS, Settings
+from commitizen.exceptions import InvalidConfigurationError
 
 if TYPE_CHECKING:
     import sys
@@ -14,6 +15,8 @@
     else:
         from typing import Self
 
+_VALID_CONFIG_KEYS: frozenset[str] = frozenset(Settings.__annotations__)
+
 
 class BaseConfig:
     def __init__(self) -> None:
@@ -47,6 +50,12 @@ def set_key(self, key: str, value: object) -> Self:
         raise NotImplementedError()
 
     def update(self, data: Settings) -> None:
+        if self._settings.get("strict_config"):
+            unknown = sorted(set(data) - _VALID_CONFIG_KEYS)
+            if unknown:
+                raise InvalidConfigurationError(
+                    f"Unknown commitizen config keys: {', '.join(unknown)}"
+                )
         self._settings.update(data)
 
     def _parse_setting(self, data: bytes | str) -> None:

commitizen/config/json_config.py

@@ -65,6 +65,6 @@ def _parse_setting(self, data: bytes | str) -> None:
             raise InvalidConfigurationError(f"Failed to parse {self.path}: {e}")
 
         try:
-            self.settings.update(doc["commitizen"])
+            self.update(doc["commitizen"])
         except KeyError:
             pass

commitizen/config/toml_config.py

@@ -65,6 +65,6 @@ def _parse_setting(self, data: bytes | str) -> None:
             raise InvalidConfigurationError(f"Failed to parse {self.path}: {e}")
 
         try:
-            self.settings.update(doc["tool"]["commitizen"])  # type: ignore[index,typeddict-item] # TODO: fix this
+            self.update(doc["tool"]["commitizen"])  # type: ignore[index,arg-type]
         except exceptions.NonExistentKey:
             pass

commitizen/config/yaml_config.py

@@ -51,7 +51,7 @@ def _parse_setting(self, data: bytes | str) -> None:
             raise InvalidConfigurationError(f"Failed to parse {self.path}: {e}")
 
         try:
-            self.settings.update(doc["commitizen"])
+            self.update(doc["commitizen"])
         except (KeyError, TypeError):
             pass
 

commitizen/defaults.py

@@ -65,6 +65,7 @@ class Settings(TypedDict, total=False):
     version_type: str | None
     version: str | None
     breaking_change_exclamation_in_title: bool
+    strict_config: bool
 
 
 CONFIG_FILES: tuple[str, ...] = (
@@ -115,6 +116,7 @@ class Settings(TypedDict, total=False):
     "extras": {},
     "breaking_change_exclamation_in_title": False,
     "message_length_limit": 0,  # 0 for no limit
+    "strict_config": False,
 }
 
 MAJOR = "MAJOR"

tests/test_conf.py

@@ -497,3 +497,65 @@ def test_init_with_invalid_content(self, tmp_path, config_file):
         with pytest.raises(InvalidConfigurationError) as excinfo:
             YAMLConfig(data=existing_content, path=path)
         assert config_file in str(excinfo.value)
+
+
+class TestStrictConfig:
+    """Tests for the strict_config option that rejects unknown config keys."""
+
+    def test_toml_strict_config_raises_on_unknown_key(self, tmp_path):
+        data = """
+[tool.commitizen]
+strict_config = true
+tga_format = "v$version"
+"""
+        path = tmp_path / "pyproject.toml"
+        with pytest.raises(InvalidConfigurationError, match="tga_format"):
+            TomlConfig(data=data, path=path)
+
+    def test_json_strict_config_raises_on_unknown_key(self, tmp_path):
+        data = json.dumps(
+            {"commitizen": {"strict_config": True, "tga_format": "v$version"}}
+        )
+        path = tmp_path / ".cz.json"
+        with pytest.raises(InvalidConfigurationError, match="tga_format"):
+            JsonConfig(data=data, path=path)
+
+    def test_yaml_strict_config_raises_on_unknown_key(self, tmp_path):
+        data = "commitizen:\n  strict_config: true\n  tga_format: v$version\n"
+        path = tmp_path / ".cz.yaml"
+        with pytest.raises(InvalidConfigurationError, match="tga_format"):
+            YAMLConfig(data=data, path=path)
+
+    def test_strict_config_off_by_default_ignores_unknown_key(self, tmp_path):
+        data = """
+[tool.commitizen]
+tga_format = "v$version"
+"""
+        path = tmp_path / "pyproject.toml"
+        cfg = TomlConfig(data=data, path=path)
+        assert cfg.settings.get("strict_config") is False
+
+    def test_strict_config_allows_all_known_keys(self, tmp_path):
+        data = """
+[tool.commitizen]
+strict_config = true
+name = "cz_conventional_commits"
+tag_format = "v$version"
+"""
+        path = tmp_path / "pyproject.toml"
+        cfg = TomlConfig(data=data, path=path)
+        assert cfg.settings["strict_config"] is True
+        assert cfg.settings["tag_format"] == "v$version"
+
+    def test_strict_config_error_lists_all_unknown_keys(self, tmp_path):
+        data = """
+[tool.commitizen]
+strict_config = true
+typo_one = "foo"
+typo_two = "bar"
+"""
+        path = tmp_path / "pyproject.toml"
+        with pytest.raises(InvalidConfigurationError) as excinfo:
+            TomlConfig(data=data, path=path)
+        assert "typo_one" in str(excinfo.value)
+        assert "typo_two" in str(excinfo.value)