From f342be80c10981440297139ccb40521aaa25d801 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Wed, 31 Dec 2025 21:02:32 -0800
Subject: [PATCH] [testing] Avoid narrowing TypeType

This relates to changes made in #20492
---
 mypy/checker.py                     |  1 +
 test-data/unit/check-narrowing.test | 20 ++++++++++++++++++++
 test-data/unit/fixtures/type.pyi    |  1 +
 3 files changed, 22 insertions(+)

diff --git a/mypy/checker.py b/mypy/checker.py
index 4fcb1a367047..3b78c10e9930 100644
--- a/mypy/checker.py
+++ b/mypy/checker.py
@@ -6568,6 +6568,7 @@ def comparison_type_narrowing_helper(self, node: ComparisonExpr) -> tuple[TypeMa
                     isinstance(p_expr := get_proper_type(expr_type), CallableType)
                     and p_expr.is_type_obj()
                 )
+                and not isinstance(p_expr, TypeType)
             ):
                 h = literal_hash(expr)
                 if h is not None:
diff --git a/test-data/unit/check-narrowing.test b/test-data/unit/check-narrowing.test
index 64dc288e927a..e66f4b2b6a2f 100644
--- a/test-data/unit/check-narrowing.test
+++ b/test-data/unit/check-narrowing.test
@@ -2920,3 +2920,23 @@ def f2(x: Any) -> None:
         return
     reveal_type(x)  # N: Revealed type is "Any"
 [builtins fixtures/tuple.pyi]
+
+[case testNarrowTypeVarType]
+from typing import TypeVar
+
+T = TypeVar("T")
+
+class A: ...
+
+def foo(X: type[T]) -> T:
+    if X == A:
+        return X()
+    raise
+
+# It could be nice to make these two test cases consistent, but it would be tricky
+# The above case is much more common in real world code
+def bar(X: type[T]) -> T:
+    if X == A:
+        return A()  # E: Incompatible return value type (got "A", expected "T")
+    raise
+[builtins fixtures/type.pyi]
diff --git a/test-data/unit/fixtures/type.pyi b/test-data/unit/fixtures/type.pyi
index 0d93b2e1fcd6..55d84c3b3360 100644
--- a/test-data/unit/fixtures/type.pyi
+++ b/test-data/unit/fixtures/type.pyi
@@ -10,6 +10,7 @@ S = TypeVar("S")
 class object:
     def __init__(self) -> None: pass
     def __str__(self) -> 'str': pass
+    def __eq__(self, value: object, /) -> bool: ...
 
 class list(Generic[T]): pass