From d29eab8717564ae51969f3b7760f8bf5c16919d4 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 01/24] add tests

---
 mypyc/test-data/run-weakref.test | 70 ++++++++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 3 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 902c9e407ff45..892c29c50521d 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -7,7 +7,6 @@ from mypy_extensions import mypyc_attr
 @mypyc_attr(native_class=False)
 class Object:
     """some random weakreffable object"""
-    pass
 
 def test_weakref_ref():
     obj = Object()
@@ -16,6 +15,20 @@ def test_weakref_ref():
     obj = None
     assert r() is None, r()
 
+[file driver.py]
+from native import test_weakref_ref
+
+test_weakref_ref()
+
+
+[case testWeakrefRefWithCallback]
+from weakref import ref
+from mypy_extensions import mypyc_attr
+
+@mypyc_attr(native_class=False)
+class Object:
+    """some random weakreffable object"""
+
 def test_weakref_ref_with_callback():
     obj = Object()
     r = ref(obj, lambda x: x)
@@ -24,7 +37,58 @@ def test_weakref_ref_with_callback():
     assert r() is None, r()
 
 [file driver.py]
-from native import test_weakref_ref, test_weakref_ref_with_callback
+from native import test_weakref_ref_with_callback
 
-test_weakref_ref()
 test_weakref_ref_with_callback()
+
+
+[case testWeakrefProxy]
+import pytest  # type: ignore [import-not-found]
+from weakref import proxy
+from mypy_extensions import mypyc_attr
+
+@mypyc_attr(native_class=False)
+class Object:
+    """some random weakreffable object"""
+    def some_meth(self) -> int:
+        return 1
+
+def test_weakref_proxy():
+    obj = Object()
+    p = proxy(obj)
+    assert obj.some_meth() == 1
+    assert p.some_meth() == 1
+    obj = None
+    with pytest.raises(ReferenceError):
+        p.some_meth()
+
+[file driver.py]
+from native import test_weakref_proxy
+
+test_weakref_proxy()
+
+
+[case testWeakrefProxyWithCallback]
+import pytest  # type: ignore [import-not-found]
+from weakref import proxy
+from mypy_extensions import mypyc_attr
+
+@mypyc_attr(native_class=False)
+class Object:
+    """some random weakreffable object"""
+    def some_meth(self) -> int:
+        return 1
+
+def test_weakref_proxy_with_callback():
+    obj = Object()
+    p = proxy(obj, lambda x: x)
+    assert obj.some_meth() == 1
+    assert p.some_meth() == 1
+    obj = None
+    with pytest.raises(ReferenceError):
+        p.some_meth()
+
+[file driver.py]
+from native import test_weakref_proxy_with_callback
+
+test_weakref_proxy_with_callback()

From d043cda4bb5777cfa68ab5f2f566736268d0b73b Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 02/24] _weakref stubs

---
 test-data/unit/lib-stub/_weakref.pyi | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 test-data/unit/lib-stub/_weakref.pyi

diff --git a/test-data/unit/lib-stub/_weakref.pyi b/test-data/unit/lib-stub/_weakref.pyi
new file mode 100644
index 0000000000000..70012375e6451
--- /dev/null
+++ b/test-data/unit/lib-stub/_weakref.pyi
@@ -0,0 +1,11 @@
+from typing import Any, Callable, TypeVar, overload
+from weakref import CallableProxyType
+
+_C = TypeVar("_C", bound=Callable[..., Any])
+_T = TypeVar("_T")
+
+# Return CallableProxyType if object is callable, ProxyType otherwise
+@overload
+def proxy(object: _C, callback: Callable[[_C], Any] | None = None, /) -> CallableProxyType[_C]: ...
+@overload
+def proxy(object: _T, callback: Callable[[_T], Any] | None = None, /) -> Any: ...

From 81760b2eaa3e1783cb6025cc54df4e1405d79089 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 03/24] weakref stubs

---
 test-data/unit/lib-stub/weakref.pyi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/test-data/unit/lib-stub/weakref.pyi b/test-data/unit/lib-stub/weakref.pyi
index 34e01f4d48f1f..f26a52f351a3a 100644
--- a/test-data/unit/lib-stub/weakref.pyi
+++ b/test-data/unit/lib-stub/weakref.pyi
@@ -1,7 +1,9 @@
+from _weakref import proxy
 from collections.abc import Callable
-from typing import Any, Generic, TypeVar
+from typing import Any, ClassVar, Generic, TypeVar, final
 from typing_extensions import Self
 
+_C = TypeVar("_C", bound=Callable[..., Any])
 _T = TypeVar("_T")
 
 class ReferenceType(Generic[_T]):  # "weakref"
@@ -9,3 +11,12 @@ class ReferenceType(Generic[_T]):  # "weakref"
     def __new__(cls, o: _T, callback: Callable[[Self], Any] | None = ..., /) -> Self: ...
 
 ref = ReferenceType
+
+@final
+class CallableProxyType(Generic[_C]):  # "weakcallableproxy"
+    def __eq__(self, value: object, /) -> bool: ...
+    def __getattr__(self, attr: str) -> Any: ...
+    __call__: _C
+    __hash__: ClassVar[None]  # type: ignore[assignment]
+
+__all__ = ["proxy"]

From e7906258287b1cdddcb0e626b54cd82bbdbc8dcf Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 04/24] feat: new primitive for weakref.ref

---
 mypyc/test-data/run-weakref.test | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 892c29c50521d..1a95d6fbe4ffa 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -1,6 +1,7 @@
 # Test cases for weakrefs (compile and run)
 
 [case testWeakrefRef]
+import pytest  # type: ignore [import-not-found]
 from weakref import ref
 from mypy_extensions import mypyc_attr
 

From 1bcc358f31a51412dc5474024f94307f741b210f Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 05/24] feat(test): test ir

---
 mypyc/test-data/irbuild-weakref.test | 52 ++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/mypyc/test-data/irbuild-weakref.test b/mypyc/test-data/irbuild-weakref.test
index 58ac6417d2970..2180b1e747aab 100644
--- a/mypyc/test-data/irbuild-weakref.test
+++ b/mypyc/test-data/irbuild-weakref.test
@@ -49,3 +49,55 @@ def f(x, cb):
 L0:
     r0 = PyWeakref_NewRef(x, cb)
     return r0
+
+[case testWeakrefProxy]
+import weakref
+from typing import Any, Callable
+def f(x: object) -> object:
+    return weakref.proxy(x)
+
+[out]
+def f(x):
+    x, r0 :: object
+L0:
+    r0 = PyWeakref_NewProxy(x, 0)
+    return r0
+
+[case testWeakrefProxyCallback]
+import weakref
+from typing import Any, Callable
+def f(x: object, cb: Callable[[object], Any]) -> object:
+    return weakref.proxy(x, cb)
+
+[out]
+def f(x, cb):
+    x, cb, r0 :: object
+L0:
+    r0 = PyWeakref_NewProxy(x, cb)
+    return r0
+
+[case testFromWeakrefProxy]
+from typing import Any, Callable
+from weakref import proxy
+def f(x: object) -> object:
+    return proxy(x)
+
+[out]
+def f(x):
+    x, r0 :: object
+L0:
+    r0 = PyWeakref_NewProxy(x, 0)
+    return r0
+
+[case testFromWeakrefProxyCallback]
+from typing import Any, Callable
+from weakref import proxy
+def f(x: object, cb: Callable[[object], Any]) -> object:
+    return proxy(x, cb)
+
+[out]
+def f(x, cb):
+    x, cb, r0 :: object
+L0:
+    r0 = PyWeakref_NewProxy(x, cb)
+    return r0

From 996987c81bac8b4a3bc230986174b94c069fb1df Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 06/24] fix: steal maybe

---
 mypyc/primitives/weakref_ops.py | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/mypyc/primitives/weakref_ops.py b/mypyc/primitives/weakref_ops.py
index a7ac035b22a4e..48bcdb829cee9 100644
--- a/mypyc/primitives/weakref_ops.py
+++ b/mypyc/primitives/weakref_ops.py
@@ -20,3 +20,22 @@
     c_function_name="PyWeakref_NewRef",
     error_kind=ERR_MAGIC,
 )
+
+new_proxy_op = function_op(
+    name="_weakref.proxy",
+    arg_types=[object_rprimitive],
+    steals=[True],
+    return_type=object_rprimitive,
+    c_function_name="PyWeakref_NewProxy",
+    extra_int_constants=[(0, pointer_rprimitive)],
+    error_kind=ERR_MAGIC,
+)
+
+new_proxy_with_callback_op = function_op(
+    name="_weakref.proxy",
+    arg_types=[object_rprimitive, object_rprimitive],
+    steals=[True, False],
+    return_type=object_rprimitive,
+    c_function_name="PyWeakref_NewProxy",
+    error_kind=ERR_MAGIC,
+)

From 3bcada69bbbb951d2b298d39e33cdab97cac3798 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 07/24] feat(test): split up run tests

---
 mypyc/test-data/run-weakref.test | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 1a95d6fbe4ffa..892c29c50521d 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -1,7 +1,6 @@
 # Test cases for weakrefs (compile and run)
 
 [case testWeakrefRef]
-import pytest  # type: ignore [import-not-found]
 from weakref import ref
 from mypy_extensions import mypyc_attr
 

From 9d6c52ccae94eba732d8eb063be351f5a98502de Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 08/24] Update weakref_ops.py

---
 mypyc/primitives/weakref_ops.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/mypyc/primitives/weakref_ops.py b/mypyc/primitives/weakref_ops.py
index 48bcdb829cee9..85e07cdb85b7a 100644
--- a/mypyc/primitives/weakref_ops.py
+++ b/mypyc/primitives/weakref_ops.py
@@ -24,7 +24,6 @@
 new_proxy_op = function_op(
     name="_weakref.proxy",
     arg_types=[object_rprimitive],
-    steals=[True],
     return_type=object_rprimitive,
     c_function_name="PyWeakref_NewProxy",
     extra_int_constants=[(0, pointer_rprimitive)],

From 1c96658793574f49d2e33a954f1790d0200d2b84 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 09/24] finalize PR

---
 mypyc/primitives/weakref_ops.py           |  2 +-
 mypyc/test-data/fixtures/test-weakref.pyi | 10 ++++++++++
 mypyc/test-data/run-weakref.test          |  4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 mypyc/test-data/fixtures/test-weakref.pyi

diff --git a/mypyc/primitives/weakref_ops.py b/mypyc/primitives/weakref_ops.py
index 85e07cdb85b7a..f7a7406db8f94 100644
--- a/mypyc/primitives/weakref_ops.py
+++ b/mypyc/primitives/weakref_ops.py
@@ -33,7 +33,7 @@
 new_proxy_with_callback_op = function_op(
     name="_weakref.proxy",
     arg_types=[object_rprimitive, object_rprimitive],
-    steals=[True, False],
+    #steals=[True, False],
     return_type=object_rprimitive,
     c_function_name="PyWeakref_NewProxy",
     error_kind=ERR_MAGIC,
diff --git a/mypyc/test-data/fixtures/test-weakref.pyi b/mypyc/test-data/fixtures/test-weakref.pyi
new file mode 100644
index 0000000000000..80525fe07d6ad
--- /dev/null
+++ b/mypyc/test-data/fixtures/test-weakref.pyi
@@ -0,0 +1,10 @@
+class dict: ...
+class ellipsis: ...
+class int: ...
+class str: ...
+class tuple: ...
+class type: ...
+class list: ...
+class BaseException: ...
+class Exception(BaseException): ...
+class ReferenceError(Exception): ...
\ No newline at end of file
diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 892c29c50521d..0b070b1567fbb 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -58,10 +58,12 @@ def test_weakref_proxy():
     p = proxy(obj)
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
+    obj.some_meth()
     obj = None
     with pytest.raises(ReferenceError):
         p.some_meth()
 
+[builtins fixtures/test-weakref.pyi]
 [file driver.py]
 from native import test_weakref_proxy
 
@@ -84,10 +86,12 @@ def test_weakref_proxy_with_callback():
     p = proxy(obj, lambda x: x)
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
+    obj.some_meth()
     obj = None
     with pytest.raises(ReferenceError):
         p.some_meth()
 
+[builtins fixtures/test-weakref.pyi]
 [file driver.py]
 from native import test_weakref_proxy_with_callback
 

From 652de32a9f2d68cf2fb974c787ea46f5e9af072d Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 4 Aug 2025 01:59:22 +0000
Subject: [PATCH 10/24] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 mypyc/primitives/weakref_ops.py           | 2 +-
 mypyc/test-data/fixtures/test-weakref.pyi | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/mypyc/primitives/weakref_ops.py b/mypyc/primitives/weakref_ops.py
index f7a7406db8f94..21379d3b2c820 100644
--- a/mypyc/primitives/weakref_ops.py
+++ b/mypyc/primitives/weakref_ops.py
@@ -33,7 +33,7 @@
 new_proxy_with_callback_op = function_op(
     name="_weakref.proxy",
     arg_types=[object_rprimitive, object_rprimitive],
-    #steals=[True, False],
+    # steals=[True, False],
     return_type=object_rprimitive,
     c_function_name="PyWeakref_NewProxy",
     error_kind=ERR_MAGIC,
diff --git a/mypyc/test-data/fixtures/test-weakref.pyi b/mypyc/test-data/fixtures/test-weakref.pyi
index 80525fe07d6ad..73896835114bb 100644
--- a/mypyc/test-data/fixtures/test-weakref.pyi
+++ b/mypyc/test-data/fixtures/test-weakref.pyi
@@ -7,4 +7,4 @@ class type: ...
 class list: ...
 class BaseException: ...
 class Exception(BaseException): ...
-class ReferenceError(Exception): ...
\ No newline at end of file
+class ReferenceError(Exception): ...

From 23d89a261a33125f786b1fe7954b46c72701c054 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 12:18:34 -0400
Subject: [PATCH 11/24] rip out pytest.raises

---
 mypyc/test-data/run-weakref.test | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 0b070b1567fbb..287006ab0c378 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -43,7 +43,6 @@ test_weakref_ref_with_callback()
 
 
 [case testWeakrefProxy]
-import pytest  # type: ignore [import-not-found]
 from weakref import proxy
 from mypy_extensions import mypyc_attr
 
@@ -60,7 +59,7 @@ def test_weakref_proxy():
     assert p.some_meth() == 1
     obj.some_meth()
     obj = None
-    with pytest.raises(ReferenceError):
+    with assertRaises(ReferenceError):
         p.some_meth()
 
 [builtins fixtures/test-weakref.pyi]
@@ -71,7 +70,6 @@ test_weakref_proxy()
 
 
 [case testWeakrefProxyWithCallback]
-import pytest  # type: ignore [import-not-found]
 from weakref import proxy
 from mypy_extensions import mypyc_attr
 
@@ -88,7 +86,7 @@ def test_weakref_proxy_with_callback():
     assert p.some_meth() == 1
     obj.some_meth()
     obj = None
-    with pytest.raises(ReferenceError):
+    with assertRaises(ReferenceError):
         p.some_meth()
 
 [builtins fixtures/test-weakref.pyi]

From c4f596e68710fdcbdb2ae1ce9b98bc3f6bbae682 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 12:19:46 -0400
Subject: [PATCH 12/24] rip out driver.py

---
 mypyc/test-data/run-weakref.test | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 287006ab0c378..8c01ea330c5bc 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -15,11 +15,6 @@ def test_weakref_ref():
     obj = None
     assert r() is None, r()
 
-[file driver.py]
-from native import test_weakref_ref
-
-test_weakref_ref()
-
 
 [case testWeakrefRefWithCallback]
 from weakref import ref
@@ -36,11 +31,6 @@ def test_weakref_ref_with_callback():
     obj = None
     assert r() is None, r()
 
-[file driver.py]
-from native import test_weakref_ref_with_callback
-
-test_weakref_ref_with_callback()
-
 
 [case testWeakrefProxy]
 from weakref import proxy
@@ -63,10 +53,6 @@ def test_weakref_proxy():
         p.some_meth()
 
 [builtins fixtures/test-weakref.pyi]
-[file driver.py]
-from native import test_weakref_proxy
-
-test_weakref_proxy()
 
 
 [case testWeakrefProxyWithCallback]
@@ -90,7 +76,3 @@ def test_weakref_proxy_with_callback():
         p.some_meth()
 
 [builtins fixtures/test-weakref.pyi]
-[file driver.py]
-from native import test_weakref_proxy_with_callback
-
-test_weakref_proxy_with_callback()

From fe03dd6300073073fd56c89e75da0b543b4b2ebb Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 12:21:30 -0400
Subject: [PATCH 13/24] combine run tests

---
 mypyc/test-data/run-weakref.test | 37 +++-----------------------------
 1 file changed, 3 insertions(+), 34 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 8c01ea330c5bc..9e203d885e61a 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -1,12 +1,14 @@
 # Test cases for weakrefs (compile and run)
 
 [case testWeakrefRef]
-from weakref import ref
+from weakref import proxy, ref
 from mypy_extensions import mypyc_attr
 
 @mypyc_attr(native_class=False)
 class Object:
     """some random weakreffable object"""
+    def some_meth(self) -> int:
+        return 1
 
 def test_weakref_ref():
     obj = Object()
@@ -15,15 +17,6 @@ def test_weakref_ref():
     obj = None
     assert r() is None, r()
 
-
-[case testWeakrefRefWithCallback]
-from weakref import ref
-from mypy_extensions import mypyc_attr
-
-@mypyc_attr(native_class=False)
-class Object:
-    """some random weakreffable object"""
-
 def test_weakref_ref_with_callback():
     obj = Object()
     r = ref(obj, lambda x: x)
@@ -31,17 +24,6 @@ def test_weakref_ref_with_callback():
     obj = None
     assert r() is None, r()
 
-
-[case testWeakrefProxy]
-from weakref import proxy
-from mypy_extensions import mypyc_attr
-
-@mypyc_attr(native_class=False)
-class Object:
-    """some random weakreffable object"""
-    def some_meth(self) -> int:
-        return 1
-
 def test_weakref_proxy():
     obj = Object()
     p = proxy(obj)
@@ -52,19 +34,6 @@ def test_weakref_proxy():
     with assertRaises(ReferenceError):
         p.some_meth()
 
-[builtins fixtures/test-weakref.pyi]
-
-
-[case testWeakrefProxyWithCallback]
-from weakref import proxy
-from mypy_extensions import mypyc_attr
-
-@mypyc_attr(native_class=False)
-class Object:
-    """some random weakreffable object"""
-    def some_meth(self) -> int:
-        return 1
-
 def test_weakref_proxy_with_callback():
     obj = Object()
     p = proxy(obj, lambda x: x)

From 2667ae88dfa10f372e9d415e975938a613a14b13 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 12:24:13 -0400
Subject: [PATCH 14/24] test callback is called

---
 mypyc/test-data/run-weakref.test | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 9e203d885e61a..28c560b78c6e2 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -10,6 +10,8 @@ class Object:
     def some_meth(self) -> int:
         return 1
 
+_callback_called_cache: dict[str, bool] = {"ref": False, "proxy": False}
+
 def test_weakref_ref():
     obj = Object()
     r = ref(obj)
@@ -19,10 +21,11 @@ def test_weakref_ref():
 
 def test_weakref_ref_with_callback():
     obj = Object()
-    r = ref(obj, lambda x: x)
+    r = ref(obj, lambda x: _callback_called_cache["ref"] = True)
     assert r() is obj
     obj = None
     assert r() is None, r()
+    assert _callback_called_cache["ref"] is True
 
 def test_weakref_proxy():
     obj = Object()
@@ -36,12 +39,13 @@ def test_weakref_proxy():
 
 def test_weakref_proxy_with_callback():
     obj = Object()
-    p = proxy(obj, lambda x: x)
+    p = proxy(obj, lambda x: _callback_called_cache["proxy"] = True)
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
     obj.some_meth()
     obj = None
     with assertRaises(ReferenceError):
         p.some_meth()
+    assert _callback_called_cache["proxy"] is True
 
 [builtins fixtures/test-weakref.pyi]

From 4d3982985e5a01b6f060079f1c62816d3a3cd5f4 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 12:42:47 -0400
Subject: [PATCH 15/24] Update run-weakref.test

---
 mypyc/test-data/run-weakref.test | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 28c560b78c6e2..18e0c632c7cb3 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -21,7 +21,7 @@ def test_weakref_ref():
 
 def test_weakref_ref_with_callback():
     obj = Object()
-    r = ref(obj, lambda x: _callback_called_cache["ref"] = True)
+    r = ref(obj, lambda x: _callback_called_cache.__setitem__("ref", True))
     assert r() is obj
     obj = None
     assert r() is None, r()
@@ -39,7 +39,7 @@ def test_weakref_proxy():
 
 def test_weakref_proxy_with_callback():
     obj = Object()
-    p = proxy(obj, lambda x: _callback_called_cache["proxy"] = True)
+    p = proxy(obj, lambda x: _callback_called_cache.__setitem__("proxy", True))
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
     obj.some_meth()

From 78694f32856a022bb3a49351653cafdc2b9b5809 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 23:47:12 -0400
Subject: [PATCH 16/24] Update run-weakref.test

---
 mypyc/test-data/run-weakref.test | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 18e0c632c7cb3..c42a4abdd05d1 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -10,7 +10,7 @@ class Object:
     def some_meth(self) -> int:
         return 1
 
-_callback_called_cache: dict[str, bool] = {"ref": False, "proxy": False}
+_callback_called_cache = {"ref": False, "proxy": False}
 
 def test_weakref_ref():
     obj = Object()

From 5c9cab57170800ba472f947665cbecfb4c52ee1a Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Sun, 17 Aug 2025 23:56:29 -0400
Subject: [PATCH 17/24] Update run-weakref.test

---
 mypyc/test-data/run-weakref.test | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index c42a4abdd05d1..c9c845d643d65 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -3,6 +3,7 @@
 [case testWeakrefRef]
 from weakref import proxy, ref
 from mypy_extensions import mypyc_attr
+from testutil import assertRaises
 
 @mypyc_attr(native_class=False)
 class Object:

From da8e23a42f4fb7babaf87797f6a314459293afc1 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Fri, 29 Aug 2025 19:52:15 +0000
Subject: [PATCH 18/24] remove test-weakref.pyi

---
 mypyc/test-data/fixtures/ir.py            |  1 +
 mypyc/test-data/fixtures/test-weakref.pyi | 10 ----------
 mypyc/test-data/run-weakref.test          |  2 --
 3 files changed, 1 insertion(+), 12 deletions(-)
 delete mode 100644 mypyc/test-data/fixtures/test-weakref.pyi

diff --git a/mypyc/test-data/fixtures/ir.py b/mypyc/test-data/fixtures/ir.py
index 661ae50fd5f3c..dba33fd504635 100644
--- a/mypyc/test-data/fixtures/ir.py
+++ b/mypyc/test-data/fixtures/ir.py
@@ -340,6 +340,7 @@ class RuntimeError(Exception): pass
 class UnicodeEncodeError(RuntimeError): pass
 class UnicodeDecodeError(RuntimeError): pass
 class NotImplementedError(RuntimeError): pass
+class ReferenceError(Exception): pass
 
 class StopIteration(Exception):
     value: Any
diff --git a/mypyc/test-data/fixtures/test-weakref.pyi b/mypyc/test-data/fixtures/test-weakref.pyi
deleted file mode 100644
index 73896835114bb..0000000000000
--- a/mypyc/test-data/fixtures/test-weakref.pyi
+++ /dev/null
@@ -1,10 +0,0 @@
-class dict: ...
-class ellipsis: ...
-class int: ...
-class str: ...
-class tuple: ...
-class type: ...
-class list: ...
-class BaseException: ...
-class Exception(BaseException): ...
-class ReferenceError(Exception): ...
diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index c9c845d643d65..f69a6812f2acd 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -48,5 +48,3 @@ def test_weakref_proxy_with_callback():
     with assertRaises(ReferenceError):
         p.some_meth()
     assert _callback_called_cache["proxy"] is True
-
-[builtins fixtures/test-weakref.pyi]

From 05513a8bb40734b790250677e2dde507b298f69a Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Tue, 2 Sep 2025 10:10:57 -0400
Subject: [PATCH 19/24] add type annotations

---
 mypyc/test-data/run-weakref.test | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index f69a6812f2acd..ababa1ccfc5e7 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -13,14 +13,14 @@ class Object:
 
 _callback_called_cache = {"ref": False, "proxy": False}
 
-def test_weakref_ref():
+def test_weakref_ref() -> None:
     obj = Object()
     r = ref(obj)
     assert r() is obj
     obj = None
     assert r() is None, r()
 
-def test_weakref_ref_with_callback():
+def test_weakref_ref_with_callback() -> None:
     obj = Object()
     r = ref(obj, lambda x: _callback_called_cache.__setitem__("ref", True))
     assert r() is obj
@@ -28,7 +28,7 @@ def test_weakref_ref_with_callback():
     assert r() is None, r()
     assert _callback_called_cache["ref"] is True
 
-def test_weakref_proxy():
+def test_weakref_proxy() -> None:
     obj = Object()
     p = proxy(obj)
     assert obj.some_meth() == 1
@@ -38,7 +38,7 @@ def test_weakref_proxy():
     with assertRaises(ReferenceError):
         p.some_meth()
 
-def test_weakref_proxy_with_callback():
+def test_weakref_proxy_with_callback() -> None:
     obj = Object()
     p = proxy(obj, lambda x: _callback_called_cache.__setitem__("proxy", True))
     assert obj.some_meth() == 1

From fd7632c6ea81bcbf9e3c61b268ddfe0b8bd173c9 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Thu, 4 Sep 2025 11:18:14 -0400
Subject: [PATCH 20/24] add `ReferenceType.__call__` to stubs

---
 test-data/unit/lib-stub/weakref.pyi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test-data/unit/lib-stub/weakref.pyi b/test-data/unit/lib-stub/weakref.pyi
index f26a52f351a3a..7d11b65d45481 100644
--- a/test-data/unit/lib-stub/weakref.pyi
+++ b/test-data/unit/lib-stub/weakref.pyi
@@ -9,6 +9,7 @@ _T = TypeVar("_T")
 class ReferenceType(Generic[_T]):  # "weakref"
     __callback__: Callable[[Self], Any]
     def __new__(cls, o: _T, callback: Callable[[Self], Any] | None = ..., /) -> Self: ...
+    def __call__(self) -> _T | None: ...
 
 ref = ReferenceType
 

From fb9e02d42be9212df35239f8f5e0b51e685d9c0a Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Thu, 4 Sep 2025 11:38:15 -0400
Subject: [PATCH 21/24] fix mypy errs

---
 mypyc/test-data/run-weakref.test | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index ababa1ccfc5e7..2629d549f079b 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -14,14 +14,14 @@ class Object:
 _callback_called_cache = {"ref": False, "proxy": False}
 
 def test_weakref_ref() -> None:
-    obj = Object()
+    obj: Object | None = Object()
     r = ref(obj)
     assert r() is obj
     obj = None
     assert r() is None, r()
 
 def test_weakref_ref_with_callback() -> None:
-    obj = Object()
+    obj: Object | None = Object()
     r = ref(obj, lambda x: _callback_called_cache.__setitem__("ref", True))
     assert r() is obj
     obj = None
@@ -29,7 +29,7 @@ def test_weakref_ref_with_callback() -> None:
     assert _callback_called_cache["ref"] is True
 
 def test_weakref_proxy() -> None:
-    obj = Object()
+    obj: Object | None = Object()
     p = proxy(obj)
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
@@ -39,7 +39,7 @@ def test_weakref_proxy() -> None:
         p.some_meth()
 
 def test_weakref_proxy_with_callback() -> None:
-    obj = Object()
+    obj: Object | None = Object()
     p = proxy(obj, lambda x: _callback_called_cache.__setitem__("proxy", True))
     assert obj.some_meth() == 1
     assert p.some_meth() == 1

From 8f5bf72bd1bfc2640299364ba225ccec06016937 Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Thu, 4 Sep 2025 11:53:12 -0400
Subject: [PATCH 22/24] disable error code union-attr

---
 mypyc/test-data/run-weakref.test | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index 2629d549f079b..cd8feccf6a627 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -1,6 +1,7 @@
 # Test cases for weakrefs (compile and run)
 
 [case testWeakrefRef]
+# mypy: disable-error-code="union-attr"
 from weakref import proxy, ref
 from mypy_extensions import mypyc_attr
 from testutil import assertRaises

From 5563d05ff3704979e7cfbac4403b156dc378f43d Mon Sep 17 00:00:00 2001
From: BobTheBuidler <70677534+BobTheBuidler@users.noreply.github.com>
Date: Thu, 4 Sep 2025 12:00:37 -0400
Subject: [PATCH 23/24] fix: use Optional instead of |

---
 mypyc/test-data/run-weakref.test | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/mypyc/test-data/run-weakref.test b/mypyc/test-data/run-weakref.test
index cd8feccf6a627..0a0e180d635d7 100644
--- a/mypyc/test-data/run-weakref.test
+++ b/mypyc/test-data/run-weakref.test
@@ -5,6 +5,7 @@
 from weakref import proxy, ref
 from mypy_extensions import mypyc_attr
 from testutil import assertRaises
+from typing import Optional
 
 @mypyc_attr(native_class=False)
 class Object:
@@ -15,14 +16,14 @@ class Object:
 _callback_called_cache = {"ref": False, "proxy": False}
 
 def test_weakref_ref() -> None:
-    obj: Object | None = Object()
+    obj: Optional[Object] = Object()
     r = ref(obj)
     assert r() is obj
     obj = None
     assert r() is None, r()
 
 def test_weakref_ref_with_callback() -> None:
-    obj: Object | None = Object()
+    obj: Optional[Object] = Object()
     r = ref(obj, lambda x: _callback_called_cache.__setitem__("ref", True))
     assert r() is obj
     obj = None
@@ -30,7 +31,7 @@ def test_weakref_ref_with_callback() -> None:
     assert _callback_called_cache["ref"] is True
 
 def test_weakref_proxy() -> None:
-    obj: Object | None = Object()
+    obj: Optional[Object] = Object()
     p = proxy(obj)
     assert obj.some_meth() == 1
     assert p.some_meth() == 1
@@ -40,7 +41,7 @@ def test_weakref_proxy() -> None:
         p.some_meth()
 
 def test_weakref_proxy_with_callback() -> None:
-    obj: Object | None = Object()
+    obj: Optional[Object] = Object()
     p = proxy(obj, lambda x: _callback_called_cache.__setitem__("proxy", True))
     assert obj.some_meth() == 1
     assert p.some_meth() == 1

From 796d5ce4ce52089b3d636cada76fcb6cd48614cd Mon Sep 17 00:00:00 2001
From: BobTheBuidler <bobthebuidlerdefi@gmail.com>
Date: Fri, 5 Sep 2025 03:09:45 +0000
Subject: [PATCH 24/24] fix stubs

---
 test-data/unit/lib-stub/_weakref.pyi | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test-data/unit/lib-stub/_weakref.pyi b/test-data/unit/lib-stub/_weakref.pyi
index 70012375e6451..50c59b65e2677 100644
--- a/test-data/unit/lib-stub/_weakref.pyi
+++ b/test-data/unit/lib-stub/_weakref.pyi
@@ -1,11 +1,11 @@
 from typing import Any, Callable, TypeVar, overload
-from weakref import CallableProxyType
+from weakref import CallableProxyType, ProxyType
 
 _C = TypeVar("_C", bound=Callable[..., Any])
 _T = TypeVar("_T")
 
 # Return CallableProxyType if object is callable, ProxyType otherwise
 @overload
-def proxy(object: _C, callback: Callable[[_C], Any] | None = None, /) -> CallableProxyType[_C]: ...
+def proxy(object: _C, callback: Callable[[CallableProxyType[_C]], Any] | None = None, /) -> CallableProxyType[_C]: ...
 @overload
-def proxy(object: _T, callback: Callable[[_T], Any] | None = None, /) -> Any: ...
+def proxy(object: _T, callback: Callable[[ProxyType[_T]], Any] | None = None, /) -> ProxyType[_T]: ...