Add: Allow to check if a Config has a key

This will allow for easier handling of config setting changes and to
check whether a setting is available.

autohooks/config.py

@@ -71,6 +71,12 @@ def is_empty(self) -> bool:
         """
         return not bool(self._config_dict)
 
+    def has_key(self, key: str) -> bool:
+        """
+        Returns True if the key is in the config.
+        """
+        return key in self._config_dict
+
 
 def _gather_mode(mode_string: Optional[str]) -> Mode:
     """

tests/test_config.py

@@ -246,6 +246,12 @@ def test_config_point_syntax(self):
         self.assertFalse(bar_config.is_empty())
         self.assertEqual(bar_config.get_value("lorem"), "ipsum")
 
+    def test_has_key(self):
+        config = Config()
+        self.assertFalse(config.has_key("foo"))
+        config = Config({"foo": "bar"})
+        self.assertTrue(config.has_key("foo"))
+
 
 if __name__ == "__main__":
     unittest.main()