fix: Don't conflate passed argument with class member (instance attribute)

Issue-357: #357

Author: pawamoy

src/_griffe/expressions.py

@@ -150,8 +150,9 @@ def canonical_path(self) -> str:
 
     @property
     def canonical_name(self) -> str:
-        """Name of the expressed name/attribute."""
-        return self.canonical_path.rsplit(".", 1)[-1]
+        """Name of the expressed name/attribute/parameter."""
+        # We must handle things like `griffe.Visitor` and `griffe.Visitor(code)`.
+        return self.canonical_path.rsplit(".", 1)[-1].split("(", 1)[-1].removesuffix(")")
 
     @property
     def is_classvar(self) -> bool:

src/_griffe/models.py

@@ -2063,6 +2063,23 @@ def annotation(self) -> str | Expr | None:
         """The type annotation of the returned value."""
         return self.returns
 
+    def resolve(self, name: str) -> str:
+        """Resolve a name within this object's and parents' scope.
+
+        Parameters:
+            name: The name to resolve.
+
+        Raises:
+            NameResolutionError: When the name could not be resolved.
+
+        Returns:
+            The resolved name.
+        """
+        # We're in an `__init__` method and name is a parameter name.
+        if self.parent and self.name == "__init__" and name in self.parameters:
+            return f"{self.parent.path}({name})"
+        return super().resolve(name)
+
     def as_dict(self, **kwargs: Any) -> dict[str, Any]:
         """Return this function's data as a dictionary.
 

tests/test_expressions.py

@@ -92,3 +92,21 @@ def test_length_one_tuple_as_string() -> None:
     code = "x = ('a',)"
     with temporary_visited_module(code) as module:
         assert str(module["x"].value) == "('a',)"
+
+
+def test_resolving_init_parameter() -> None:
+    """Instance attribute values should resolve to matching parameters.
+
+    They must not resolve to the member of the same name in the same class,
+    or to objects with the same name in higher scopes.
+    """
+    with temporary_visited_module(
+        """
+        x = 1
+
+        class Class:
+            def __init__(self, x: int):
+                self.x: int = x
+        """,
+    ) as module:
+        assert module["Class.x"].value.canonical_path == "module.Class(x)"