fix: Attributes without annotations cannot be dataclass parameters

All dataclass parameters have annotations. When determining which of the attributes of dataclass are parameters, we explicitly check against that condition. This help us filter out obvious non-candidates that may otherwise fall through.

PR-297: #297

src/griffe/extensions/dataclasses.py

@@ -80,6 +80,10 @@ def _dataclass_parameters(class_: Class) -> list[Parameter]:
         if member.is_attribute:
             member = cast(Attribute, member)
 
+            # All dataclass parameters have annotations
+            if member.annotation is None:
+                continue
+
             # Attributes that have labels for these characteristics are
             # not class parameters:
             #   - @property

tests/test_dataclasses.py

@@ -421,3 +421,27 @@ class Derived(Base):
         assert param_b.docstring.value == "Parameter b"
         assert param_c.docstring is None
         assert param_d.docstring.value == "Parameter d"
+
+
+def test_attributes_that_have_no_annotations() -> None:
+    """Dataclass attributes that have no annotatations are not parameters."""
+    code = """
+        from dataclasses import dataclass, field
+
+        @dataclass
+        class Base:
+            a: int
+            b: str = field(init=False)
+            c = 3  # class attribute
+
+        @dataclass
+        class Derived(Base):
+            a = 1  # no effect on the parameter status of a
+            b = "b"  # inherited non-parameter
+            d: float = 4
+    """
+    with temporary_visited_package("package", {"__init__.py": code}) as module:
+        base_params = [p.name for p in module["Base"].parameters]
+        derived_params = [p.name for p in module["Derived"].parameters]
+        assert base_params == ["self", "a"]
+        assert derived_params == ["self", "a", "d"]