From 3ec2859619526e4629666163c454c92dddcbedc2 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 15:40:17 +0100
Subject: [PATCH 01/14] Infer GenericAlias when indexing types

---
 mypy/checkexpr.py | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 1cea4f6c19e64..7d235f38b4c95 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -4341,6 +4341,11 @@ def visit_index_with_type(
             left_type.upper_bound, "__getitem__"
         ):
             return self.visit_index_with_type(left_type.upper_bound, e, original_type)
+        elif (
+            isinstance(left_type, FunctionLike)
+            and left_type.is_type_obj()
+        ):
+            return self.named_type("types.GenericAlias")
         else:
             result, method_type = self.check_method_call_by_name(
                 "__getitem__", left_type, [e.index], [ARG_POS], e, original_type=original_type

From 75c1151fc548179a308d165a47b96712941af069 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 16:11:29 +0100
Subject: [PATCH 02/14] Allow special forms to be used to form unions using |

E.g. Callable is declared as a special form in typeshed
---
 mypy/checkexpr.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 7d235f38b4c95..160fa3446009d 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -4346,6 +4346,9 @@ def visit_index_with_type(
             and left_type.is_type_obj()
         ):
             return self.named_type("types.GenericAlias")
+        elif isinstance(left_type, Instance) and left_type.type.fullname == "typing._SpecialForm":
+            # Allow special forms to be indexed and used to create union types
+            return self.named_type("typing._SpecialForm")
         else:
             result, method_type = self.check_method_call_by_name(
                 "__getitem__", left_type, [e.index], [ARG_POS], e, original_type=original_type

From 6b4205056f7475108b52edb0b2e25e357055a9c1 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 16:53:33 +0100
Subject: [PATCH 03/14] Give typing._SpecialForm as runtime type of 'Any'

---
 mypy/checkexpr.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 160fa3446009d..9626cc13bdc2b 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -428,6 +428,9 @@ def analyze_var_ref(self, var: Var, context: Context) -> Type:
         if var.type:
             var_type = get_proper_type(var.type)
             if isinstance(var_type, Instance):
+                if var.fullname == "typing.Any":
+                    # The typeshed type is 'object'; give a more useful type in runtime context
+                    return self.named_type("typing._SpecialForm")
                 if self.is_literal_context() and var_type.last_known_value is not None:
                     return var_type.last_known_value
                 if var.name in {"True", "False"}:

From 4457c946f43ffe15fec97ea0368bd0fc8940a59f Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 16:54:03 +0100
Subject: [PATCH 04/14] Test various types in a type alias context (runtime
 context)

---
 test-data/unit/check-python312.test     | 23 +++++++++++++++++++++++
 test-data/unit/fixtures/typing-full.pyi |  5 ++++-
 test-data/unit/lib-stub/types.pyi       |  4 +++-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index 348f2d11f9a78..0878aed16d320 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1591,3 +1591,26 @@ c: E[str]
 d: E[int]  # E: Type argument "int" of "E" must be a subtype of "str"
 [builtins fixtures/tuple.pyi]
 [typing fixtures/typing-full.pyi]
+
+[case testPEP695TypeAliasWithDifferentTargetTypes]
+# flags: --enable-incomplete-feature=NewGenericSyntax
+import types  # We need GenericAlias from here, and test stubs don't bring in 'types'
+from typing import Any, Callable
+
+type A1 = type[int]
+type A2 = type[int] | None
+type A3 = None | type[int]
+type A4 = type[Any]
+
+type B1[**P, R] = Callable[P, R] | None
+type B2[**P, R] = None | Callable[P, R]
+type B3 = Callable[[str], int]
+type B4 = Callable[..., int]
+
+type C1 = A1 | None
+type C2 = None | A1
+
+type D1 = Any | None
+type D2 = None | Any
+[builtins fixtures/tuple.pyi]
+[typing fixtures/typing-full.pyi]
diff --git a/test-data/unit/fixtures/typing-full.pyi b/test-data/unit/fixtures/typing-full.pyi
index 9d61361fc16ec..e77e77efc58f9 100644
--- a/test-data/unit/fixtures/typing-full.pyi
+++ b/test-data/unit/fixtures/typing-full.pyi
@@ -12,6 +12,8 @@ class GenericMeta(type): pass
 
 class _SpecialForm:
     def __getitem__(self, index: Any) -> Any: ...
+    def __or__(self, other): ...
+    def __ror__(self, other): ...
 class TypeVar:
     def __init__(self, name, *args, bound=None): ...
     def __or__(self, other): ...
@@ -21,7 +23,7 @@ class TypeVarTuple: ...
 def cast(t, o): ...
 def assert_type(o, t): ...
 overload = 0
-Any = 0
+Any = object()
 Optional = 0
 Generic = 0
 Protocol = 0
@@ -216,3 +218,4 @@ class TypeAliasType:
     ) -> None: ...
 
     def __or__(self, other: Any) -> Any: ...
+    def __ror__(self, other: Any) -> Any: ...
diff --git a/test-data/unit/lib-stub/types.pyi b/test-data/unit/lib-stub/types.pyi
index c3ac244c2a518..3f713c31e4174 100644
--- a/test-data/unit/lib-stub/types.pyi
+++ b/test-data/unit/lib-stub/types.pyi
@@ -9,7 +9,9 @@ class ModuleType:
     __file__: str
     def __getattr__(self, name: str) -> Any: pass
 
-class GenericAlias: ...
+class GenericAlias:
+    def __or__(self, o): ...
+    def __ror__(self, o): ...
 
 if sys.version_info >= (3, 10):
     class NoneType:

From c001a93b3015375a7ce91e4ed567e2a09bdd9a19 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 17:33:16 +0100
Subject: [PATCH 05/14] Ignore a self check error

---
 mypy/stubgenc.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypy/stubgenc.py b/mypy/stubgenc.py
index 9acd3f171a416..bacb68f6d1c73 100755
--- a/mypy/stubgenc.py
+++ b/mypy/stubgenc.py
@@ -733,7 +733,7 @@ def generate_property_stub(
 
     def get_type_fullname(self, typ: type) -> str:
         """Given a type, return a string representation"""
-        if typ is Any:
+        if typ is Any:  # type: ignore[comparison-overlap]
             return "Any"
         typename = getattr(typ, "__qualname__", typ.__name__)
         module_name = self.get_obj_module(typ)

From a1f55f68dda4e16bd7ed69365c04cb0f6a914dce Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 17:33:45 +0100
Subject: [PATCH 06/14] Fix issue

---
 mypy/checkexpr.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 9626cc13bdc2b..26739e5efa7e4 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -4347,6 +4347,7 @@ def visit_index_with_type(
         elif (
             isinstance(left_type, FunctionLike)
             and left_type.is_type_obj()
+            and left_type.type_object().type_vars
         ):
             return self.named_type("types.GenericAlias")
         elif isinstance(left_type, Instance) and left_type.type.fullname == "typing._SpecialForm":

From 35997def4f68cb2424f6ba1e8c6ff768940eb972 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 17:34:26 +0100
Subject: [PATCH 07/14] Update tests and test stubs

---
 mypyc/test-data/fixtures/typing-full.pyi             | 2 +-
 test-data/unit/check-classes.test                    | 3 +++
 test-data/unit/check-functions.test                  | 5 ++---
 test-data/unit/check-generics.test                   | 6 ++++--
 test-data/unit/check-type-object-type-inference.test | 3 ++-
 test-data/unit/fixtures/typing-async.pyi             | 4 +++-
 test-data/unit/fixtures/typing-medium.pyi            | 2 +-
 test-data/unit/fixtures/typing-namedtuple.pyi        | 4 +++-
 test-data/unit/fixtures/typing-override.pyi          | 5 +++--
 test-data/unit/fixtures/typing-typeddict-iror.pyi    | 4 +++-
 test-data/unit/fixtures/typing-typeddict.pyi         | 4 +++-
 test-data/unit/lib-stub/typing.pyi                   | 4 +++-
 12 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/mypyc/test-data/fixtures/typing-full.pyi b/mypyc/test-data/fixtures/typing-full.pyi
index 8bb3b1398f87d..32cdacfc0f536 100644
--- a/mypyc/test-data/fixtures/typing-full.pyi
+++ b/mypyc/test-data/fixtures/typing-full.pyi
@@ -15,7 +15,7 @@ class _SpecialForm:
 
 cast = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
diff --git a/test-data/unit/check-classes.test b/test-data/unit/check-classes.test
index 427133eca10bb..edfbb571e3b9b 100644
--- a/test-data/unit/check-classes.test
+++ b/test-data/unit/check-classes.test
@@ -4786,12 +4786,15 @@ def g(x: Type[S]) -> str:
     return reveal_type(x * 0)  # N: Revealed type is "builtins.str"
 
 [case testMetaclassGetitem]
+import types
+
 class M(type):
     def __getitem__(self, key) -> int: return 1
 
 class A(metaclass=M): pass
 
 reveal_type(A[M])  # N: Revealed type is "builtins.int"
+[builtins fixtures/tuple.pyi]
 
 [case testMetaclassSelfType]
 from typing import TypeVar, Type
diff --git a/test-data/unit/check-functions.test b/test-data/unit/check-functions.test
index ef6ca9f3b2850..29cd977fe5d63 100644
--- a/test-data/unit/check-functions.test
+++ b/test-data/unit/check-functions.test
@@ -1779,10 +1779,10 @@ def Arg(x, y): pass
 F = Callable[[Arg(int, 'x')], int]  # E: Invalid argument constructor "__main__.Arg"
 
 [case testCallableParsingFromExpr]
-
 from typing import Callable, List
 from mypy_extensions import Arg, VarArg, KwArg
 import mypy_extensions
+import types  # Needed for type checking
 
 def WrongArg(x, y): return y
 # Note that for this test, the 'Value of type "int" is not indexable' errors are silly,
@@ -1799,11 +1799,10 @@ L = Callable[[Arg(name='x', type=int)], int] # ok
 # I have commented out the following test because I don't know how to expect the "defined here" note part of the error.
 # M = Callable[[Arg(gnome='x', type=int)], int]   E: Invalid type alias: expression is not a valid type   E: Unexpected keyword argument "gnome" for "Arg"
 N = Callable[[Arg(name=None, type=int)], int] # ok
-O = Callable[[List[Arg(int)]], int]  # E: Invalid type alias: expression is not a valid type  # E: Value of type "int" is not indexable  # E: Type expected within [...] # E: The type "Type[List[Any]]" is not generic and not indexable
+O = Callable[[List[Arg(int)]], int]  # E: Invalid type alias: expression is not a valid type  # E: Value of type "int" is not indexable  # E: Type expected within [...]
 P = Callable[[mypy_extensions.VarArg(int)], int] # ok
 Q = Callable[[Arg(int, type=int)], int]  # E: Invalid type alias: expression is not a valid type  # E: Value of type "int" is not indexable  # E: "Arg" gets multiple values for keyword argument "type"
 R = Callable[[Arg(int, 'x', name='y')], int]  # E: Invalid type alias: expression is not a valid type  # E: Value of type "int" is not indexable  # E: "Arg" gets multiple values for keyword argument "name"
-
 [builtins fixtures/dict.pyi]
 
 [case testCallableParsing]
diff --git a/test-data/unit/check-generics.test b/test-data/unit/check-generics.test
index abcb2a4bbc482..eb0d1aa5bd7a9 100644
--- a/test-data/unit/check-generics.test
+++ b/test-data/unit/check-generics.test
@@ -454,11 +454,12 @@ A[int, str, int]() # E: Type application has too many types (2 expected)
 [out]
 
 [case testInvalidTypeApplicationType]
+import types
 a: A
 class A: pass
 a[A]()  # E: Value of type "A" is not indexable
 A[A]()  # E: The type "Type[A]" is not generic and not indexable
-[out]
+[builtins fixtures/tuple.pyi]
 
 [case testTypeApplicationArgTypes]
 from typing import TypeVar, Generic
@@ -513,8 +514,9 @@ Alias[int]("a")  # E: Argument 1 to "Node" has incompatible type "str"; expected
 [out]
 
 [case testTypeApplicationCrash]
+import types
 type[int] # this was crashing, see #2302 (comment)  # E: The type "Type[type]" is not generic and not indexable
-[out]
+[builtins fixtures/tuple.pyi]
 
 
 -- Generic type aliases
diff --git a/test-data/unit/check-type-object-type-inference.test b/test-data/unit/check-type-object-type-inference.test
index baeca1e22ac7c..5a4afa0c92481 100644
--- a/test-data/unit/check-type-object-type-inference.test
+++ b/test-data/unit/check-type-object-type-inference.test
@@ -2,6 +2,7 @@
 # flags: --python-version 3.9
 from typing import TypeVar, Generic, Type
 from abc import abstractmethod
+import types  # Explicitly bring in stubs for 'types'
 
 T = TypeVar('T')
 class E(Generic[T]):
@@ -37,5 +38,5 @@ def i(f: F):
     f.f(tuple[int,tuple[int,str]]).e( (27,(28,'z')) )  # OK
     reveal_type(f.f(tuple[int,tuple[int,str]]).e)  # N: Revealed type is "def (t: Tuple[builtins.int, Tuple[builtins.int, builtins.str]]) -> builtins.str"
 
-x = tuple[int,str][str]  # E: The type "Type[Tuple[Any, ...]]" is not generic and not indexable
+x = tuple[int,str][str]  # False negative
 [builtins fixtures/tuple.pyi]
diff --git a/test-data/unit/fixtures/typing-async.pyi b/test-data/unit/fixtures/typing-async.pyi
index 9897dfd0b2701..03728f8223162 100644
--- a/test-data/unit/fixtures/typing-async.pyi
+++ b/test-data/unit/fixtures/typing-async.pyi
@@ -10,7 +10,7 @@ from abc import abstractmethod, ABCMeta
 
 cast = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
@@ -125,3 +125,5 @@ class AsyncContextManager(Generic[T]):
     def __aenter__(self) -> Awaitable[T]: pass
     # Use Any because not all the precise types are in the fixtures.
     def __aexit__(self, exc_type: Any, exc_value: Any, traceback: Any) -> Awaitable[Any]: pass
+
+class _SpecialForm: pass
diff --git a/test-data/unit/fixtures/typing-medium.pyi b/test-data/unit/fixtures/typing-medium.pyi
index c19c5d5d96e20..c722a9ddb12c8 100644
--- a/test-data/unit/fixtures/typing-medium.pyi
+++ b/test-data/unit/fixtures/typing-medium.pyi
@@ -8,7 +8,7 @@
 
 cast = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
diff --git a/test-data/unit/fixtures/typing-namedtuple.pyi b/test-data/unit/fixtures/typing-namedtuple.pyi
index f4744575fc092..a464edfdf96c6 100644
--- a/test-data/unit/fixtures/typing-namedtuple.pyi
+++ b/test-data/unit/fixtures/typing-namedtuple.pyi
@@ -1,6 +1,8 @@
+class _SpecialForm: pass
+
 TypeVar = 0
 Generic = 0
-Any = 0
+Any = object()
 overload = 0
 Type = 0
 Literal = 0
diff --git a/test-data/unit/fixtures/typing-override.pyi b/test-data/unit/fixtures/typing-override.pyi
index 606ca63d4f0d8..e9d2dfcf55c45 100644
--- a/test-data/unit/fixtures/typing-override.pyi
+++ b/test-data/unit/fixtures/typing-override.pyi
@@ -1,6 +1,6 @@
 TypeVar = 0
 Generic = 0
-Any = 0
+Any = object()
 overload = 0
 Type = 0
 Literal = 0
@@ -21,5 +21,6 @@ class Mapping(Iterable[KT], Generic[KT, T_co]):
     def keys(self) -> Iterable[T]: pass  # Approximate return type
     def __getitem__(self, key: T) -> T_co: pass
 
-
 def override(__arg: T) -> T: ...
+
+class _SpecialForm: pass
diff --git a/test-data/unit/fixtures/typing-typeddict-iror.pyi b/test-data/unit/fixtures/typing-typeddict-iror.pyi
index e452c8497109d..845ac6cf208fd 100644
--- a/test-data/unit/fixtures/typing-typeddict-iror.pyi
+++ b/test-data/unit/fixtures/typing-typeddict-iror.pyi
@@ -12,7 +12,7 @@ from abc import ABCMeta
 cast = 0
 assert_type = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
@@ -64,3 +64,5 @@ class _TypedDict(Mapping[str, object]):
     def __ror__(self, __value: dict[str, Any]) -> dict[str, object]: ...
     # supposedly incompatible definitions of __or__ and __ior__
     def __ior__(self, __value: Self) -> Self: ...  # type: ignore[misc]
+
+class _SpecialForm: pass
diff --git a/test-data/unit/fixtures/typing-typeddict.pyi b/test-data/unit/fixtures/typing-typeddict.pyi
index 24a2f13289812..d136ac4ab8bee 100644
--- a/test-data/unit/fixtures/typing-typeddict.pyi
+++ b/test-data/unit/fixtures/typing-typeddict.pyi
@@ -11,7 +11,7 @@ from abc import ABCMeta
 cast = 0
 assert_type = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
@@ -71,3 +71,5 @@ class _TypedDict(Mapping[str, object]):
     def pop(self, k: NoReturn, default: T = ...) -> object: ...
     def update(self: T, __m: T) -> None: ...
     def __delitem__(self, k: NoReturn) -> None: ...
+
+class _SpecialForm: pass
diff --git a/test-data/unit/lib-stub/typing.pyi b/test-data/unit/lib-stub/typing.pyi
index 5f458ca687c0f..3cb164140883d 100644
--- a/test-data/unit/lib-stub/typing.pyi
+++ b/test-data/unit/lib-stub/typing.pyi
@@ -11,7 +11,7 @@
 cast = 0
 assert_type = 0
 overload = 0
-Any = 0
+Any = object()
 Union = 0
 Optional = 0
 TypeVar = 0
@@ -63,3 +63,5 @@ class Coroutine(Awaitable[V], Generic[T, U, V]): pass
 def final(meth: T) -> T: pass
 
 def reveal_type(__obj: T) -> T: pass
+
+class _SpecialForm: pass

From ad39b49c2121936fb22109c4789a5ebeb2ff097d Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 17:43:58 +0100
Subject: [PATCH 08/14] Update tests

---
 test-data/unit/check-python312.test | 2 +-
 test-data/unit/pythoneval.test      | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index 0878aed16d320..0c8c767d18138 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1612,5 +1612,5 @@ type C2 = None | A1
 
 type D1 = Any | None
 type D2 = None | Any
-[builtins fixtures/tuple.pyi]
+[builtins fixtures/type.pyi]
 [typing fixtures/typing-full.pyi]
diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index a76d3abd71148..9096a7b3ed003 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -1606,8 +1606,8 @@ class Foo(Enum):
     Bar: Foo = Callable[[str], None]
     Baz: Foo = Callable[[Dict[str, "Missing"]], None]
 [out]
-_testEnumValueWithPlaceholderNodeType.py:5: error: Incompatible types in assignment (expression has type "object", variable has type "Foo")
-_testEnumValueWithPlaceholderNodeType.py:6: error: Incompatible types in assignment (expression has type "object", variable has type "Foo")
+_testEnumValueWithPlaceholderNodeType.py:5: error: Incompatible types in assignment (expression has type "<typing special form>", variable has type "Foo")
+_testEnumValueWithPlaceholderNodeType.py:6: error: Incompatible types in assignment (expression has type "<typing special form>", variable has type "Foo")
 _testEnumValueWithPlaceholderNodeType.py:6: error: Name "Missing" is not defined
 
 [case testTypeshedRecursiveTypesExample]

From c402c100ae7b5dc7dbd65911fb586def039b9aa7 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Mon, 17 Jun 2024 17:44:51 +0100
Subject: [PATCH 09/14] Update test case

---
 test-data/unit/check-python312.test | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index 0c8c767d18138..6657040c83e9f 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1595,7 +1595,7 @@ d: E[int]  # E: Type argument "int" of "E" must be a subtype of "str"
 [case testPEP695TypeAliasWithDifferentTargetTypes]
 # flags: --enable-incomplete-feature=NewGenericSyntax
 import types  # We need GenericAlias from here, and test stubs don't bring in 'types'
-from typing import Any, Callable
+from typing import Any, Callable, List
 
 type A1 = type[int]
 type A2 = type[int] | None
@@ -1612,5 +1612,9 @@ type C2 = None | A1
 
 type D1 = Any | None
 type D2 = None | Any
+
+type E1 = List[int]
+type E2 = List[int] | None
+type E3 = None | List[int]
 [builtins fixtures/type.pyi]
 [typing fixtures/typing-full.pyi]

From e1ff8bb527116f5959ef66e38b9e2854491d1b3c Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Tue, 18 Jun 2024 10:56:15 +0100
Subject: [PATCH 10/14] Minor refactoring

---
 test-data/unit/fixtures/typing-namedtuple.pyi | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test-data/unit/fixtures/typing-namedtuple.pyi b/test-data/unit/fixtures/typing-namedtuple.pyi
index a464edfdf96c6..bcdcfc44c3d21 100644
--- a/test-data/unit/fixtures/typing-namedtuple.pyi
+++ b/test-data/unit/fixtures/typing-namedtuple.pyi
@@ -1,5 +1,3 @@
-class _SpecialForm: pass
-
 TypeVar = 0
 Generic = 0
 Any = object()
@@ -28,3 +26,5 @@ class NamedTuple(tuple[Any, ...]):
     def __init__(self, typename: str, fields: Iterable[tuple[str, Any]] = ...) -> None: ...
     @overload
     def __init__(self, typename: str, fields: None = None, **kwargs: Any) -> None: ...
+
+class _SpecialForm: pass

From 62d17076b4bb31974d480eacd5bb30edd329dc75 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Tue, 18 Jun 2024 10:59:25 +0100
Subject: [PATCH 11/14] Test more cases

---
 mypyc/test-data/fixtures/typing-full.pyi |  4 ++--
 test-data/unit/check-python312.test      | 10 +++++++++-
 test-data/unit/fixtures/typing-full.pyi  |  2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/mypyc/test-data/fixtures/typing-full.pyi b/mypyc/test-data/fixtures/typing-full.pyi
index 32cdacfc0f536..6b6aba6802b15 100644
--- a/mypyc/test-data/fixtures/typing-full.pyi
+++ b/mypyc/test-data/fixtures/typing-full.pyi
@@ -16,7 +16,6 @@ class _SpecialForm:
 cast = 0
 overload = 0
 Any = object()
-Union = 0
 Optional = 0
 TypeVar = 0
 Generic = 0
@@ -28,11 +27,12 @@ Type = 0
 no_type_check = 0
 ClassVar = 0
 Final = 0
-Literal = 0
 TypedDict = 0
 NoReturn = 0
 NewType = 0
 Callable: _SpecialForm
+Union: _SpecialForm
+Literal: _SpecialForm
 
 T = TypeVar('T')
 T_co = TypeVar('T_co', covariant=True)
diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index 6657040c83e9f..212768142f3ea 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1595,7 +1595,7 @@ d: E[int]  # E: Type argument "int" of "E" must be a subtype of "str"
 [case testPEP695TypeAliasWithDifferentTargetTypes]
 # flags: --enable-incomplete-feature=NewGenericSyntax
 import types  # We need GenericAlias from here, and test stubs don't bring in 'types'
-from typing import Any, Callable, List
+from typing import Any, Callable, List, Literal
 
 type A1 = type[int]
 type A2 = type[int] | None
@@ -1616,5 +1616,13 @@ type D2 = None | Any
 type E1 = List[int]
 type E2 = List[int] | None
 type E3 = None | List[int]
+
+type F1 = Literal[1]
+type F2 = Literal['x'] | None
+type F3 = None | Literal[True]
+
+type G1 = tuple[int, Any]
+type G2 = tuple[int, Any] | None
+type G3 = None | tuple[int, Any]
 [builtins fixtures/type.pyi]
 [typing fixtures/typing-full.pyi]
diff --git a/test-data/unit/fixtures/typing-full.pyi b/test-data/unit/fixtures/typing-full.pyi
index e77e77efc58f9..8e0116aab1c29 100644
--- a/test-data/unit/fixtures/typing-full.pyi
+++ b/test-data/unit/fixtures/typing-full.pyi
@@ -33,7 +33,6 @@ Type = 0
 no_type_check = 0
 ClassVar = 0
 Final = 0
-Literal = 0
 TypedDict = 0
 NoReturn = 0
 NewType = 0
@@ -41,6 +40,7 @@ Self = 0
 Unpack = 0
 Callable: _SpecialForm
 Union: _SpecialForm
+Literal: _SpecialForm
 
 T = TypeVar('T')
 T_co = TypeVar('T_co', covariant=True)

From 5e42cd957248b483af6d60a7860ce4d4e9b35960 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Tue, 18 Jun 2024 16:56:33 +0100
Subject: [PATCH 12/14] Test more and some fixes

---
 mypy/checkexpr.py                   | 26 +++++------
 test-data/unit/check-generics.test  |  1 +
 test-data/unit/check-python312.test | 19 +++++++-
 test-data/unit/pythoneval.test      | 70 ++++++++++++++++++++++++++++-
 4 files changed, 100 insertions(+), 16 deletions(-)

diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
index 26739e5efa7e4..734a9e1687bd7 100644
--- a/mypy/checkexpr.py
+++ b/mypy/checkexpr.py
@@ -4334,22 +4334,22 @@ def visit_index_with_type(
                 return self.nonliteral_tuple_index_helper(left_type, index)
         elif isinstance(left_type, TypedDictType):
             return self.visit_typeddict_index_expr(left_type, e.index)
-        elif (
-            isinstance(left_type, FunctionLike)
-            and left_type.is_type_obj()
-            and left_type.type_object().is_enum
-        ):
-            return self.visit_enum_index_expr(left_type.type_object(), e.index, e)
-        elif isinstance(left_type, TypeVarType) and not self.has_member(
+        elif isinstance(left_type, FunctionLike) and left_type.is_type_obj():
+            if left_type.type_object().is_enum:
+                return self.visit_enum_index_expr(left_type.type_object(), e.index, e)
+            elif left_type.type_object().type_vars:
+                return self.named_type("types.GenericAlias")
+            elif (
+                left_type.type_object().fullname == "builtins.type"
+                and self.chk.options.python_version >= (3, 9)
+            ):
+                # builtins.type is special: it's not generic in stubs, but it supports indexing
+                return self.named_type("typing._SpecialForm")
+
+        if isinstance(left_type, TypeVarType) and not self.has_member(
             left_type.upper_bound, "__getitem__"
         ):
             return self.visit_index_with_type(left_type.upper_bound, e, original_type)
-        elif (
-            isinstance(left_type, FunctionLike)
-            and left_type.is_type_obj()
-            and left_type.type_object().type_vars
-        ):
-            return self.named_type("types.GenericAlias")
         elif isinstance(left_type, Instance) and left_type.type.fullname == "typing._SpecialForm":
             # Allow special forms to be indexed and used to create union types
             return self.named_type("typing._SpecialForm")
diff --git a/test-data/unit/check-generics.test b/test-data/unit/check-generics.test
index eb0d1aa5bd7a9..a95f73706aa70 100644
--- a/test-data/unit/check-generics.test
+++ b/test-data/unit/check-generics.test
@@ -460,6 +460,7 @@ class A: pass
 a[A]()  # E: Value of type "A" is not indexable
 A[A]()  # E: The type "Type[A]" is not generic and not indexable
 [builtins fixtures/tuple.pyi]
+[typing fixtures/typing-full.pyi]
 
 [case testTypeApplicationArgTypes]
 from typing import TypeVar, Generic
diff --git a/test-data/unit/check-python312.test b/test-data/unit/check-python312.test
index 212768142f3ea..7c3d565b1b446 100644
--- a/test-data/unit/check-python312.test
+++ b/test-data/unit/check-python312.test
@@ -1595,7 +1595,16 @@ d: E[int]  # E: Type argument "int" of "E" must be a subtype of "str"
 [case testPEP695TypeAliasWithDifferentTargetTypes]
 # flags: --enable-incomplete-feature=NewGenericSyntax
 import types  # We need GenericAlias from here, and test stubs don't bring in 'types'
-from typing import Any, Callable, List, Literal
+from typing import Any, Callable, List, Literal, TypedDict
+
+# Test that various type expressions don't generate false positives as type alias
+# values, as they are type checked as expressions. There is a similar test case in
+# pythoneval.test that uses typeshed stubs.
+
+class C[T]: pass
+
+class TD(TypedDict):
+    x: int
 
 type A1 = type[int]
 type A2 = type[int] | None
@@ -1624,5 +1633,13 @@ type F3 = None | Literal[True]
 type G1 = tuple[int, Any]
 type G2 = tuple[int, Any] | None
 type G3 = None | tuple[int, Any]
+
+type H1 = TD
+type H2 = TD | None
+type H3 = None | TD
+
+type I1 = C[int]
+type I2 = C[Any] | None
+type I3 = None | C[TD]
 [builtins fixtures/type.pyi]
 [typing fixtures/typing-full.pyi]
diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index 9096a7b3ed003..6e1bc68b434c7 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -1781,9 +1781,9 @@ C = str | int
 D: TypeAlias = str | int
 [out]
 _testTypeAliasNotSupportedWithNewStyleUnion.py:3: error: Invalid type alias: expression is not a valid type
-_testTypeAliasNotSupportedWithNewStyleUnion.py:3: error: The type "Type[type]" is not generic and not indexable
+_testTypeAliasNotSupportedWithNewStyleUnion.py:3: error: Unsupported left operand type for | ("<typing special form>")
 _testTypeAliasNotSupportedWithNewStyleUnion.py:4: error: Invalid type alias: expression is not a valid type
-_testTypeAliasNotSupportedWithNewStyleUnion.py:4: error: The type "Type[type]" is not generic and not indexable
+_testTypeAliasNotSupportedWithNewStyleUnion.py:4: error: Unsupported left operand type for | ("Type[str]")
 _testTypeAliasNotSupportedWithNewStyleUnion.py:5: error: Invalid type alias: expression is not a valid type
 _testTypeAliasNotSupportedWithNewStyleUnion.py:5: error: Unsupported left operand type for | ("Type[str]")
 _testTypeAliasNotSupportedWithNewStyleUnion.py:6: error: Invalid type alias: expression is not a valid type
@@ -2117,3 +2117,69 @@ def func(
     a2 = action  # Error
 [out]
 _testPEP695VarianceInference.py:17: error: Incompatible types in assignment (expression has type "Job[None]", variable has type "Job[int]")
+
+[case testPEP695TypeAliasWithDifferentTargetTypes]
+# flags: --python-version=3.12 --enable-incomplete-feature=NewGenericSyntax
+from typing import Any, Callable, List, Literal, TypedDict, overload
+
+class C[T]: pass
+
+class O[T]:
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, x: int) -> None: ...
+    def __init__(self, x: int = 0) -> None:
+        pass
+
+class TD(TypedDict):
+    x: int
+
+type A1 = type[int]
+type A2 = type[int] | None
+type A3 = None | type[int]
+type A4 = type[Any]
+type A5 = type[C] | None
+type A6 = None | type[C]
+type A7 = type[O] | None
+type A8 = None | type[O]
+
+type B1[**P, R] = Callable[P, R] | None
+type B2[**P, R] = None | Callable[P, R]
+type B3 = Callable[[str], int]
+type B4 = Callable[..., int]
+
+type C1 = A1 | None
+type C2 = None | A1
+
+type D1 = Any | None
+type D2 = None | Any
+
+type E1 = List[int]
+type E2 = List[int] | None
+type E3 = None | List[int]
+
+type F1 = Literal[1]
+type F2 = Literal['x'] | None
+type F3 = None | Literal[True]
+
+type G1 = tuple[int, Any]
+type G2 = tuple[int, Any] | None
+type G3 = None | tuple[int, Any]
+
+type H1 = TD
+type H2 = TD | None
+type H3 = None | TD
+
+type I1 = C[int]
+type I2 = C[Any] | None
+type I3 = None | C[TD]
+type I4 = O[int] | None
+type I5 = None | O[int]
+
+type J1[T] = T | None
+type J2[T] = None | T
+type J3[*Ts] = tuple[*Ts]
+type J4[T] = J1[T] | None
+type J5[T] = None | J1[T]
+type J6[*Ts] = J3[*Ts] | None

From 0f939da7c7cbb521aee5718c7d63177480fd5fc7 Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Tue, 18 Jun 2024 16:58:33 +0100
Subject: [PATCH 13/14] Test more

---
 test-data/unit/pythoneval.test | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index 6e1bc68b434c7..6feec73bb3b95 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -2120,7 +2120,7 @@ _testPEP695VarianceInference.py:17: error: Incompatible types in assignment (exp
 
 [case testPEP695TypeAliasWithDifferentTargetTypes]
 # flags: --python-version=3.12 --enable-incomplete-feature=NewGenericSyntax
-from typing import Any, Callable, List, Literal, TypedDict, overload
+from typing import Any, Callable, List, Literal, TypedDict, overload, TypeAlias, TypeVar
 
 class C[T]: pass
 
@@ -2135,6 +2135,10 @@ class O[T]:
 class TD(TypedDict):
     x: int
 
+S = TypeVar("S")
+A = list[S]
+B: TypeAlias = list[S]
+
 type A1 = type[int]
 type A2 = type[int] | None
 type A3 = None | type[int]
@@ -2183,3 +2187,8 @@ type J3[*Ts] = tuple[*Ts]
 type J4[T] = J1[T] | None
 type J5[T] = None | J1[T]
 type J6[*Ts] = J3[*Ts] | None
+
+type K1 = A[int] | None
+type K2 = None | A[int]
+type K3 = B[int] | None
+type K4 = None | B[int]

From 4f8b8ad81fa6098edbdf233683ab3e7dc531043e Mon Sep 17 00:00:00 2001
From: Jukka Lehtosalo <jukka.lehtosalo@iki.fi>
Date: Tue, 18 Jun 2024 16:59:23 +0100
Subject: [PATCH 14/14] Test more

---
 test-data/unit/pythoneval.test | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/test-data/unit/pythoneval.test b/test-data/unit/pythoneval.test
index 6feec73bb3b95..bdf830050f9fd 100644
--- a/test-data/unit/pythoneval.test
+++ b/test-data/unit/pythoneval.test
@@ -2120,7 +2120,7 @@ _testPEP695VarianceInference.py:17: error: Incompatible types in assignment (exp
 
 [case testPEP695TypeAliasWithDifferentTargetTypes]
 # flags: --python-version=3.12 --enable-incomplete-feature=NewGenericSyntax
-from typing import Any, Callable, List, Literal, TypedDict, overload, TypeAlias, TypeVar
+from typing import Any, Callable, List, Literal, TypedDict, overload, TypeAlias, TypeVar, Never
 
 class C[T]: pass
 
@@ -2192,3 +2192,6 @@ type K1 = A[int] | None
 type K2 = None | A[int]
 type K3 = B[int] | None
 type K4 = None | B[int]
+
+type L1 = Never
+type L2 = list[Never]