Keep introspection defaults constructor-owned

Stop treating dataclass and object instance current values as signature defaults. Dataclass instance analysis now reuses the dataclass type defaults, object instance analysis preserves constructor defaults, and tests document that ObjectState-owned current values are separate from callable defaults.\n\nValidation: PYTHONPATH=src uv run --no-sync pytest tests/test_signature_analyzer.py tests/test_unified_parameter_analyzer.py -q

Author: trissim

src/python_introspect/signature_analyzer.py

@@ -1302,23 +1302,13 @@ def extract_field_documentation_from_context(field_name: str, context_types: lis
 
     @staticmethod
     def _analyze_dataclass_instance(instance: object) -> Dict[str, ParameterInfo]:
-        """Extract parameter information from a dataclass instance."""
-        try:
-            # Get the type and analyze it
-            dataclass_type = type(instance)
-            parameters = SignatureAnalyzer._analyze_dataclass(dataclass_type)
-
-            for name, param_info in parameters.items():
-                current_value = object.__getattribute__(instance, name)
-                parameters[name] = ParameterInfo(
-                    name=param_info.name,
-                    param_type=param_info.param_type,
-                    default_value=current_value,
-                    is_required=param_info.is_required,
-                    description=param_info.description
-                )
+        """Extract parameter information from a dataclass instance.
 
-            return parameters
+        Defaults come from the dataclass type, not from current instance values.
+        Instance values are caller-owned current state, not signature defaults.
+        """
+        try:
+            return SignatureAnalyzer._analyze_dataclass(type(instance))
 
         except Exception:
             return {}

src/python_introspect/unified_parameter_analyzer.py

@@ -302,15 +302,10 @@ def _analyze_object_instance(instance: object) -> Dict[str, UnifiedParameterInfo
                 # Add parameters that haven't been seen yet (most specific wins)
                 for param_name, param_info in class_params.items():
                     if param_name not in all_params and param_name != 'kwargs':
-                        instance_values = vars(instance)
-                        default_value = instance_values.get(
-                            param_name,
-                            param_info.default_value,
-                        )
                         all_params[param_name] = UnifiedParameterInfo(
                             name=param_name,
                             param_type=param_info.param_type,
-                            default_value=default_value,
+                            default_value=param_info.default_value,
                             is_required=param_info.is_required,
                             description=param_info.description,
                             source_type="object_instance"

tests/test_signature_analyzer.py

@@ -136,8 +136,8 @@ class Config:
         analyzer = SignatureAnalyzer()
         params = analyzer.analyze(instance)
 
-        assert params["name"].default_value == "custom"
-        assert params["value"].default_value == 42
+        assert params["name"].default_value == "default"
+        assert params["value"].default_value == 10
 
     def test_analyze_method(self):
         """Test analyzing class methods."""

tests/test_unified_parameter_analyzer.py

@@ -67,8 +67,8 @@ class Config:
         analyzer = UnifiedParameterAnalyzer()
         params = analyzer.analyze(instance)
 
-        assert params["name"].default_value == "custom"
-        assert params["value"].default_value == 42
+        assert params["name"].default_value == "default"
+        assert params["value"].default_value == 10
         assert params["name"].source_type == "dataclass_instance"
 
     def test_analyze_with_exclusions(self):
@@ -320,9 +320,10 @@ def __init__(self, name: str, value: int = 10):
         # Should get parameters from __init__
         assert "name" in params
         assert "value" in params
-        # Instance values should be used
-        assert params["name"].default_value == "test"
-        assert params["value"].default_value == 20
+        # Constructor defaults remain the default authority; instance values are
+        # current state owned by callers such as ObjectState, not defaults.
+        assert params["name"].default_value is None
+        assert params["value"].default_value == 10
 
     def test_analyze_inherited_parameters(self):
         """Test analyzing object with inherited parameters."""