How about this time? Is this a correct Singleton?

barcode_validator/config.py

@@ -26,13 +26,13 @@ class Config:
     def __new__(cls):
         if cls._instance is None:
             cls._instance = super(Config, cls).__new__(cls)
+            cls._instance._initialize()
         return cls._instance
 
-    def __init__(self):
-        if not hasattr(self, 'initialized'):
-            self.config_data = None
-            self.config_path = None
-            self.initialized = True
+    def _initialize(self):
+        self.config_data = None
+        self.config_path = None
+        self.initialized = False
 
     @classmethod
     def reset(cls):
@@ -42,9 +42,9 @@ def reset(cls):
     def load_config(self, config_path):
         """
         Load the configuration from a YAML file.
-        :param: config_path (str): Path to the configuration YAML file.
-        :raise: FileNotFoundError: If the config file doesn't exist.
-        yaml.YAMLError: If there's an error parsing the YAML file.
+        :param config_path: Path to the configuration YAML file.
+        :raise FileNotFoundError: If the config file doesn't exist.
+        :raise yaml.YAMLError: If there's an error parsing the YAML file.
         """
         self.config_path = config_path
         if not os.path.exists(config_path):
@@ -58,6 +58,7 @@ def load_config(self, config_path):
 
         # Convert relative paths to absolute paths
         self._process_relative_paths(os.path.dirname(os.path.abspath(config_path)))
+        self.initialized = True
 
     def _process_relative_paths(self, config_dir):
         """

tests/test_config.py

@@ -117,24 +117,40 @@ def test_contains_method(config_instance, valid_config_data):
     assert "non_existent_key" not in config_instance
 
 
-def test_config_singleton():
-
-    # Reset the singleton instance
+def test_config_class():
+    # Reset the singleton for testing purposes
     Config.reset()
 
-    # Construct and check path to expected default config file
+    # Get the directory of the current file (assumed to be in the tests folder)
     current_dir = Path(__file__).parent
     default_config_path = current_dir.parent / 'config' / 'config.yml'
-    if not default_config_path.exists():
-        raise FileNotFoundError(f"Default config file not found at {default_config_path}")
 
-    # Load the config file twice
+    # Initialize the first instance
     config1 = Config()
+    assert not config1.initialized, "Config should not be initialized before loading"
+
     config1.load_config(str(default_config_path))
+    assert config1.initialized, "Config should be initialized after loading"
+
+    # Create a second instance
     config2 = Config()
 
-    # Additional checks
+    # They should be the same object and both initialized
     assert config1 is config2, "Config objects are not the same instance"
-    assert config1.config_path == str(default_config_path), "Config path is incorrect"
-    assert config1.config_data is not None, "Config data is None"
-    assert 'constrain' in config1.config_data, "'constrain' key is missing from config data"
+    assert config2.initialized, "Second instance should be initialized"
+
+    # Check if the second instance has the loaded configuration
+    assert config2.config_path == str(default_config_path), "Config path is not preserved in the second instance"
+    assert config2.config_data is not None, "Config data is None in the second instance"
+    assert 'constrain' in config2.config_data, "'constrain' key is missing from config data in the second instance"
+
+    # Test string representation
+    str_repr = str(config1)
+    assert "Initialized: True" in str_repr, "String representation should show initialized as True"
+    assert str(default_config_path) in str_repr, "String representation should include the config path"
+
+    # Test creating a new instance after reset
+    Config.reset()
+    config3 = Config()
+    assert not config3.initialized, "New instance after reset should not be initialized"
+    assert config3 is not config1, "New instance after reset should be a different object"