improvement: TupleTypeHint is now a subclass of ClassTypeHint; ClassTypeHint.bases no longer returns none

Author: NiklasRosenstein

.changelog/_unreleased.toml

@@ -0,0 +1,5 @@
+[[entries]]
+id = "641cd28b-3814-4b62-8bd1-c6b88fc71d5a"
+type = "improvement"
+description = "`TupleTypeHint` is now a subclass of `ClassTypeHint`; `ClassTypeHint.bases` no longer returns none"
+author = "@NiklasRosenstein"

src/typeapi/typehint.py

@@ -268,7 +268,7 @@ def type(self) -> type:
         assert False, "ClassTypeHint not initialized from a real type or a generic that points to a real type."
 
     @property
-    def bases(self) -> "Tuple[Any, ...] | None":
+    def bases(self) -> "Tuple[Any, ...]":
         return get_type_hint_original_bases(self.type)
 
     def get_parameter_map(self) -> Dict[Any, Any]:
@@ -419,7 +419,7 @@ def expr(self) -> str:
         return self._forward_ref.__forward_arg__
 
 
-class TupleTypeHint(TypeHint):
+class TupleTypeHint(ClassTypeHint):
     def __init__(self, hint: object, source: "Any | None") -> None:
         super().__init__(hint, source)
         if self._args == ((),):

src/typeapi/typehint_test.py

@@ -50,7 +50,7 @@ def test__TypeHint__list_generic() -> None:
     assert str(hint.parameters) == "(~T,)"
     assert len(hint) == 0
     assert hint.type is list
-    assert hint.bases is None
+    assert hint.bases == ()
 
 
 def test__TypeHint__list_templatized() -> None:
@@ -62,7 +62,7 @@ def test__TypeHint__list_templatized() -> None:
     assert str(hint.parameters) == "(~T,)"
     assert len(hint) == 1
     assert hint.type is list
-    assert hint.bases is None
+    assert hint.bases == ()
 
 
 def test__TypeHint__list_specialized() -> None:
@@ -74,12 +74,12 @@ def test__TypeHint__list_specialized() -> None:
     assert hint.parameters == ()
     assert len(hint) == 1
     assert hint.type is list
-    assert hint.bases is None
+    assert hint.bases == ()
 
     hint_0 = hint[0]
     assert isinstance(hint_0, ClassTypeHint)
     assert hint_0.type == int
-    assert hint_0.bases is None
+    assert hint_0.bases == ()
 
 
 @mark.parametrize(
@@ -442,6 +442,7 @@ def test__TypeHint__native_tuple_type() -> None:
     assert hint.args == (Any,)
     assert hint.parameters == ()
     assert hint.repeated
+    assert hint.bases == ()
 
     hint = TypeHint(Tuple[Any, ...])
     assert isinstance(hint, TupleTypeHint), hint
@@ -450,6 +451,8 @@ def test__TypeHint__native_tuple_type() -> None:
     assert hint.origin == tuple
     assert hint.args == (Any,)
     assert hint.parameters == ()
+    assert hint.repeated
+    assert hint.bases == ()
 
 
 def test__TypeHint__empty_tuple() -> None:

src/typeapi/utils.py

@@ -98,7 +98,7 @@ def get_type_hint_origin_or_none(hint: object) -> "Any | None":
     return hint_origin
 
 
-def get_type_hint_original_bases(hint: object) -> "Tuple[Any, ...] | None":
+def get_type_hint_original_bases(hint: object) -> "Tuple[Any, ...]":
     """
     Returns the original bases of a generic type.
     """
@@ -108,7 +108,7 @@ def get_type_hint_original_bases(hint: object) -> "Tuple[Any, ...] | None":
     if orig_bases is not None and IS_PYTHON_AT_LAST_3_6 and getattr(hint, "__args__", None):
         orig_bases = None
 
-    return orig_bases
+    return orig_bases or ()
 
 
 def get_type_hint_args(hint: object) -> Tuple[Any, ...]:

src/typeapi/utils_test.py

@@ -49,8 +49,8 @@ def test__typing_List__introspection():
     if sys.version_info[:2] <= (3, 6):
         assert get_type_hint_original_bases(List) == (list, MutableSequence[_T])
     else:
-        assert get_type_hint_original_bases(List) is None
-    assert get_type_hint_original_bases(List[int]) is None
+        assert get_type_hint_original_bases(List) == ()
+    assert get_type_hint_original_bases(List[int]) == ()
 
     # Generic-form parameters:
 
@@ -176,7 +176,7 @@ class MyGeneric(Generic[T, U]):
     assert get_type_hint_origin_or_none(MyGeneric) is None
     assert get_type_hint_origin_or_none(MyGeneric[int, str]) is MyGeneric
     assert get_type_hint_original_bases(MyGeneric) == (Generic[T, U],)
-    assert get_type_hint_original_bases(MyGeneric[int, str]) is None
+    assert get_type_hint_original_bases(MyGeneric[int, str]) == ()
 
     # Generic-form parameters:
 
@@ -234,7 +234,7 @@ class SubGeneric(MyGeneric[T], AnotherGeneric[int], int):
     assert get_type_hint_origin_or_none(SubGeneric) is None
     assert get_type_hint_origin_or_none(SubGeneric[int]) is SubGeneric
     assert get_type_hint_original_bases(SubGeneric) == (MyGeneric[T], AnotherGeneric[int], int)
-    assert get_type_hint_original_bases(SubGeneric[int]) is None
+    assert get_type_hint_original_bases(SubGeneric[int]) == ()
 
 
 @pytest.mark.parametrize(