From 05f6995d7715edee1d355fcafe330b196a0a5244 Mon Sep 17 00:00:00 2001
From: LaBatata101 <labatata101@gmail.com>
Date: Wed, 30 Apr 2025 17:15:39 -0300
Subject: [PATCH 1/2] [red-knot] Add tests for classes that have incompatible
 `__new__` and `__init__` methods

---
 .../resources/mdtest/call/constructor.md      | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md b/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
index 56a49fc13f97c..292f8b0e09b9c 100644
--- a/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
@@ -323,3 +323,57 @@ reveal_type(Foo(1))  # revealed: Foo
 # error: [too-many-positional-arguments] "Too many positional arguments to bound method `__init__`: expected 1, got 2"
 reveal_type(Foo(1, 2))  # revealed: Foo
 ```
+
+### Incompatible signatures
+
+```py
+import abc
+
+class Foo:
+    def __new__(cls) -> "Foo":
+        return object.__new__(cls)
+    def __init__(self, x):
+        self.x = 42
+
+# error: [missing-argument] "No argument provided for required parameter `x` of bound method `__init__`"
+reveal_type(Foo())  # revealed: Foo
+
+# error: [too-many-positional-arguments] "Too many positional arguments to function `__new__`: expected 0, got 1"
+reveal_type(Foo(42))  # revealed: Foo
+
+class Foo2:
+    def __new__(cls, x) -> "Foo2":
+        return object.__new__(cls)
+    def __init__(self):
+        pass
+
+# error: [missing-argument] "No argument provided for required parameter `x` of function `__new__`"
+reveal_type(Foo2())  # revealed: Foo2
+
+# error: [too-many-positional-arguments] "Too many positional arguments to bound method `__init__`: expected 0, got 1"
+reveal_type(Foo2(42))  # revealed: Foo2
+
+class Foo3(metaclass=abc.ABCMeta):
+    def __new__(cls) -> "Foo3":
+        return object.__new__(cls)
+    def __init__(self, x):
+        self.x = 42
+
+# error: [missing-argument] "No argument provided for required parameter `x` of bound method `__init__`"
+reveal_type(Foo3())  # revealed: Foo3
+
+# error: [too-many-positional-arguments] "Too many positional arguments to function `__new__`: expected 0, got 1"
+reveal_type(Foo3(42))  # revealed: Foo3
+
+class Foo4(metaclass=abc.ABCMeta):
+    def __new__(cls, x) -> "Foo4":
+        return object.__new__(cls)
+    def __init__(self):
+        pass
+
+# error: [missing-argument] "No argument provided for required parameter `x` of function `__new__`"
+reveal_type(Foo4())  # revealed: Foo4
+
+# error: [too-many-positional-arguments] "Too many positional arguments to bound method `__init__`: expected 0, got 1"
+reveal_type(Foo4(42))  # revealed: Foo4
+```

From 6d5000c922145bed20ec089cb2c782f199aa11fb Mon Sep 17 00:00:00 2001
From: Carl Meyer <carl@astral.sh>
Date: Wed, 30 Apr 2025 13:37:25 -0700
Subject: [PATCH 2/2] pre-commit

---
 .../resources/mdtest/call/constructor.md                      | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md b/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
index d0f92f50b8cc9..db20ce4a962a4 100644
--- a/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/constructor.md
@@ -351,6 +351,7 @@ import abc
 class Foo:
     def __new__(cls) -> "Foo":
         return object.__new__(cls)
+
     def __init__(self, x):
         self.x = 42
 
@@ -363,6 +364,7 @@ reveal_type(Foo(42))  # revealed: Foo
 class Foo2:
     def __new__(cls, x) -> "Foo2":
         return object.__new__(cls)
+
     def __init__(self):
         pass
 
@@ -375,6 +377,7 @@ reveal_type(Foo2(42))  # revealed: Foo2
 class Foo3(metaclass=abc.ABCMeta):
     def __new__(cls) -> "Foo3":
         return object.__new__(cls)
+
     def __init__(self, x):
         self.x = 42
 
@@ -387,6 +390,7 @@ reveal_type(Foo3(42))  # revealed: Foo3
 class Foo4(metaclass=abc.ABCMeta):
     def __new__(cls, x) -> "Foo4":
         return object.__new__(cls)
+
     def __init__(self):
         pass