[ty] Fix false-positive diagnostics on super() calls (#20814)

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Alex Waygood 2025-10-13 11:57:46 +01:00 committed by GitHub
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@ -14,9 +14,16 @@ common usage.
### Explicit Super Object
<!-- snapshot-diagnostics -->
`super(pivot_class, owner)` performs attribute lookup along the MRO, starting immediately after the
specified pivot class.
```toml
[environment]
python-version = "3.12"
```
```py
class A:
def a(self): ...
@ -34,21 +41,15 @@ reveal_type(C.__mro__) # revealed: tuple[<class 'C'>, <class 'B'>, <class 'A'>,
super(C, C()).a
super(C, C()).b
# error: [unresolved-attribute] "Type `<super: <class 'C'>, C>` has no attribute `c`"
super(C, C()).c
super(C, C()).c # error: [unresolved-attribute]
super(B, C()).a
# error: [unresolved-attribute] "Type `<super: <class 'B'>, C>` has no attribute `b`"
super(B, C()).b
# error: [unresolved-attribute] "Type `<super: <class 'B'>, C>` has no attribute `c`"
super(B, C()).c
super(B, C()).b # error: [unresolved-attribute]
super(B, C()).c # error: [unresolved-attribute]
# error: [unresolved-attribute] "Type `<super: <class 'A'>, C>` has no attribute `a`"
super(A, C()).a
# error: [unresolved-attribute] "Type `<super: <class 'A'>, C>` has no attribute `b`"
super(A, C()).b
# error: [unresolved-attribute] "Type `<super: <class 'A'>, C>` has no attribute `c`"
super(A, C()).c
super(A, C()).a # error: [unresolved-attribute]
super(A, C()).b # error: [unresolved-attribute]
super(A, C()).c # error: [unresolved-attribute]
reveal_type(super(C, C()).a) # revealed: bound method C.a() -> Unknown
reveal_type(super(C, C()).b) # revealed: bound method C.b() -> Unknown
@ -56,12 +57,80 @@ reveal_type(super(C, C()).aa) # revealed: int
reveal_type(super(C, C()).bb) # revealed: int
```
Examples of explicit `super()` with unusual types. We allow almost any type to be passed as the
second argument to `super()` -- the only exceptions are "pure abstract" types such as `Callable` and
synthesized `Protocol`s that cannot be upcast to, or interpreted as, a non-`object` nominal type.
```py
import types
from typing_extensions import Callable, TypeIs, Literal, TypedDict
def f(): ...
class Foo[T]:
def method(self): ...
@property
def some_property(self): ...
type Alias = int
class SomeTypedDict(TypedDict):
x: int
y: bytes
# revealed: <super: <class 'object'>, FunctionType>
reveal_type(super(object, f))
# revealed: <super: <class 'object'>, WrapperDescriptorType>
reveal_type(super(object, types.FunctionType.__get__))
# revealed: <super: <class 'object'>, GenericAlias>
reveal_type(super(object, Foo[int]))
# revealed: <super: <class 'object'>, _SpecialForm>
reveal_type(super(object, Literal))
# revealed: <super: <class 'object'>, TypeAliasType>
reveal_type(super(object, Alias))
# revealed: <super: <class 'object'>, MethodType>
reveal_type(super(object, Foo().method))
# revealed: <super: <class 'object'>, property>
reveal_type(super(object, Foo.some_property))
def g(x: object) -> TypeIs[list[object]]:
return isinstance(x, list)
def _(x: object, y: SomeTypedDict, z: Callable[[int, str], bool]):
if hasattr(x, "bar"):
# revealed: <Protocol with members 'bar'>
reveal_type(x)
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super(object, x))
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super(object, z))
is_list = g(x)
# revealed: TypeIs[list[object] @ x]
reveal_type(is_list)
# revealed: <super: <class 'object'>, bool>
reveal_type(super(object, is_list))
# revealed: <super: <class 'object'>, dict[Literal["x", "y"], int | bytes]>
reveal_type(super(object, y))
```
### Implicit Super Object
<!-- snapshot-diagnostics -->
The implicit form `super()` is same as `super(__class__, <first argument>)`. The `__class__` refers
to the class that contains the function where `super()` is used. The first argument refers to the
current methods first parameter (typically `self` or `cls`).
```toml
[environment]
python-version = "3.12"
```
```py
from __future__ import annotations
@ -74,6 +143,7 @@ class B(A):
def __init__(self, a: int):
# TODO: Once `Self` is supported, this should be `<super: <class 'B'>, B>`
reveal_type(super()) # revealed: <super: <class 'B'>, Unknown>
reveal_type(super(object, super())) # revealed: <super: <class 'object'>, super>
super().__init__(a)
@classmethod
@ -86,6 +156,123 @@ super(B, B(42)).__init__(42)
super(B, B).f()
```
Some examples with unusual annotations for `self` or `cls`:
```py
import enum
from typing import Any, Self, Never, Protocol, Callable
from ty_extensions import Intersection
class BuilderMeta(type):
def __new__(
cls: type[Any],
name: str,
bases: tuple[type, ...],
dct: dict[str, Any],
) -> BuilderMeta:
# revealed: <super: <class 'BuilderMeta'>, Any>
s = reveal_type(super())
# revealed: Any
return reveal_type(s.__new__(cls, name, bases, dct))
class BuilderMeta2(type):
def __new__(
cls: type[BuilderMeta2],
name: str,
bases: tuple[type, ...],
dct: dict[str, Any],
) -> BuilderMeta2:
# revealed: <super: <class 'BuilderMeta2'>, <class 'BuilderMeta2'>>
s = reveal_type(super())
# TODO: should be `BuilderMeta2` (needs https://github.com/astral-sh/ty/issues/501)
# revealed: Unknown
return reveal_type(s.__new__(cls, name, bases, dct))
class Foo[T]:
x: T
def method(self: Any):
reveal_type(super()) # revealed: <super: <class 'Foo'>, Any>
if isinstance(self, Foo):
reveal_type(super()) # revealed: <super: <class 'Foo'>, Any>
def method2(self: Foo[T]):
# revealed: <super: <class 'Foo'>, Foo[T@Foo]>
reveal_type(super())
def method3(self: Foo):
# revealed: <super: <class 'Foo'>, Foo[Unknown]>
reveal_type(super())
def method4(self: Self):
# revealed: <super: <class 'Foo'>, Foo[T@Foo]>
reveal_type(super())
def method5[S: Foo[int]](self: S, other: S) -> S:
# revealed: <super: <class 'Foo'>, Foo[int]>
reveal_type(super())
return self
def method6[S: (Foo[int], Foo[str])](self: S, other: S) -> S:
# revealed: <super: <class 'Foo'>, Foo[int]> | <super: <class 'Foo'>, Foo[str]>
reveal_type(super())
return self
def method7[S](self: S, other: S) -> S:
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super())
return self
def method8[S: int](self: S, other: S) -> S:
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super())
return self
def method9[S: (int, str)](self: S, other: S) -> S:
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super())
return self
def method10[S: Callable[..., str]](self: S, other: S) -> S:
# error: [invalid-super-argument]
# revealed: Unknown
reveal_type(super())
return self
type Alias = Bar
class Bar:
def method(self: Alias):
# revealed: <super: <class 'Bar'>, Bar>
reveal_type(super())
def pls_dont_call_me(self: Never):
# revealed: <super: <class 'Bar'>, Unknown>
reveal_type(super())
def only_call_me_on_callable_subclasses(self: Intersection[Bar, Callable[..., object]]):
# revealed: <super: <class 'Bar'>, Bar>
reveal_type(super())
class P(Protocol):
def method(self: P):
# revealed: <super: <class 'P'>, P>
reveal_type(super())
class E(enum.Enum):
X = 1
def method(self: E):
match self:
case E.X:
# revealed: <super: <class 'E'>, E>
reveal_type(super())
```
### Unbound Super Object
Calling `super(cls)` without a second argument returns an _unbound super object_. This is treated as
@ -167,11 +354,19 @@ class A:
## Built-ins and Literals
```py
from enum import Enum
reveal_type(super(bool, True)) # revealed: <super: <class 'bool'>, bool>
reveal_type(super(bool, bool())) # revealed: <super: <class 'bool'>, bool>
reveal_type(super(int, bool())) # revealed: <super: <class 'int'>, bool>
reveal_type(super(int, 3)) # revealed: <super: <class 'int'>, int>
reveal_type(super(str, "")) # revealed: <super: <class 'str'>, str>
reveal_type(super(bytes, b"")) # revealed: <super: <class 'bytes'>, bytes>
class E(Enum):
X = 42
reveal_type(super(E, E.X)) # revealed: <super: <class 'E'>, E>
```
## Descriptor Behavior with Super
@ -342,7 +537,7 @@ def f(x: int):
# error: [invalid-super-argument] "`typing.TypeAliasType` is not a valid class"
super(IntAlias, 0)
# error: [invalid-super-argument] "`Literal[""]` is not an instance or subclass of `<class 'int'>` in `super(<class 'int'>, Literal[""])` call"
# error: [invalid-super-argument] "`str` is not an instance or subclass of `<class 'int'>` in `super(<class 'int'>, str)` call"
# revealed: Unknown
reveal_type(super(int, str()))

View file

@ -0,0 +1,217 @@
---
source: crates/ty_test/src/lib.rs
expression: snapshot
---
---
mdtest name: super.md - Super - Basic Usage - Explicit Super Object
mdtest path: crates/ty_python_semantic/resources/mdtest/class/super.md
---
# Python source files
## mdtest_snippet.py
```
1 | class A:
2 | def a(self): ...
3 | aa: int = 1
4 |
5 | class B(A):
6 | def b(self): ...
7 | bb: int = 2
8 |
9 | class C(B):
10 | def c(self): ...
11 | cc: int = 3
12 |
13 | reveal_type(C.__mro__) # revealed: tuple[<class 'C'>, <class 'B'>, <class 'A'>, <class 'object'>]
14 |
15 | super(C, C()).a
16 | super(C, C()).b
17 | super(C, C()).c # error: [unresolved-attribute]
18 |
19 | super(B, C()).a
20 | super(B, C()).b # error: [unresolved-attribute]
21 | super(B, C()).c # error: [unresolved-attribute]
22 |
23 | super(A, C()).a # error: [unresolved-attribute]
24 | super(A, C()).b # error: [unresolved-attribute]
25 | super(A, C()).c # error: [unresolved-attribute]
26 |
27 | reveal_type(super(C, C()).a) # revealed: bound method C.a() -> Unknown
28 | reveal_type(super(C, C()).b) # revealed: bound method C.b() -> Unknown
29 | reveal_type(super(C, C()).aa) # revealed: int
30 | reveal_type(super(C, C()).bb) # revealed: int
31 | import types
32 | from typing_extensions import Callable, TypeIs, Literal, TypedDict
33 |
34 | def f(): ...
35 |
36 | class Foo[T]:
37 | def method(self): ...
38 | @property
39 | def some_property(self): ...
40 |
41 | type Alias = int
42 |
43 | class SomeTypedDict(TypedDict):
44 | x: int
45 | y: bytes
46 |
47 | # revealed: <super: <class 'object'>, FunctionType>
48 | reveal_type(super(object, f))
49 | # revealed: <super: <class 'object'>, WrapperDescriptorType>
50 | reveal_type(super(object, types.FunctionType.__get__))
51 | # revealed: <super: <class 'object'>, GenericAlias>
52 | reveal_type(super(object, Foo[int]))
53 | # revealed: <super: <class 'object'>, _SpecialForm>
54 | reveal_type(super(object, Literal))
55 | # revealed: <super: <class 'object'>, TypeAliasType>
56 | reveal_type(super(object, Alias))
57 | # revealed: <super: <class 'object'>, MethodType>
58 | reveal_type(super(object, Foo().method))
59 | # revealed: <super: <class 'object'>, property>
60 | reveal_type(super(object, Foo.some_property))
61 |
62 | def g(x: object) -> TypeIs[list[object]]:
63 | return isinstance(x, list)
64 |
65 | def _(x: object, y: SomeTypedDict, z: Callable[[int, str], bool]):
66 | if hasattr(x, "bar"):
67 | # revealed: <Protocol with members 'bar'>
68 | reveal_type(x)
69 | # error: [invalid-super-argument]
70 | # revealed: Unknown
71 | reveal_type(super(object, x))
72 |
73 | # error: [invalid-super-argument]
74 | # revealed: Unknown
75 | reveal_type(super(object, z))
76 |
77 | is_list = g(x)
78 | # revealed: TypeIs[list[object] @ x]
79 | reveal_type(is_list)
80 | # revealed: <super: <class 'object'>, bool>
81 | reveal_type(super(object, is_list))
82 |
83 | # revealed: <super: <class 'object'>, dict[Literal["x", "y"], int | bytes]>
84 | reveal_type(super(object, y))
```
# Diagnostics
```
error[unresolved-attribute]: Type `<super: <class 'C'>, C>` has no attribute `c`
--> src/mdtest_snippet.py:17:1
|
15 | super(C, C()).a
16 | super(C, C()).b
17 | super(C, C()).c # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
18 |
19 | super(B, C()).a
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[unresolved-attribute]: Type `<super: <class 'B'>, C>` has no attribute `b`
--> src/mdtest_snippet.py:20:1
|
19 | super(B, C()).a
20 | super(B, C()).b # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
21 | super(B, C()).c # error: [unresolved-attribute]
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[unresolved-attribute]: Type `<super: <class 'B'>, C>` has no attribute `c`
--> src/mdtest_snippet.py:21:1
|
19 | super(B, C()).a
20 | super(B, C()).b # error: [unresolved-attribute]
21 | super(B, C()).c # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
22 |
23 | super(A, C()).a # error: [unresolved-attribute]
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[unresolved-attribute]: Type `<super: <class 'A'>, C>` has no attribute `a`
--> src/mdtest_snippet.py:23:1
|
21 | super(B, C()).c # error: [unresolved-attribute]
22 |
23 | super(A, C()).a # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
24 | super(A, C()).b # error: [unresolved-attribute]
25 | super(A, C()).c # error: [unresolved-attribute]
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[unresolved-attribute]: Type `<super: <class 'A'>, C>` has no attribute `b`
--> src/mdtest_snippet.py:24:1
|
23 | super(A, C()).a # error: [unresolved-attribute]
24 | super(A, C()).b # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
25 | super(A, C()).c # error: [unresolved-attribute]
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[unresolved-attribute]: Type `<super: <class 'A'>, C>` has no attribute `c`
--> src/mdtest_snippet.py:25:1
|
23 | super(A, C()).a # error: [unresolved-attribute]
24 | super(A, C()).b # error: [unresolved-attribute]
25 | super(A, C()).c # error: [unresolved-attribute]
| ^^^^^^^^^^^^^^^
26 |
27 | reveal_type(super(C, C()).a) # revealed: bound method C.a() -> Unknown
|
info: rule `unresolved-attribute` is enabled by default
```
```
error[invalid-super-argument]: `<Protocol with members 'bar'>` is an abstract/structural type in `super(<class 'object'>, <Protocol with members 'bar'>)` call
--> src/mdtest_snippet.py:71:21
|
69 | # error: [invalid-super-argument]
70 | # revealed: Unknown
71 | reveal_type(super(object, x))
| ^^^^^^^^^^^^^^^^
72 |
73 | # error: [invalid-super-argument]
|
info: rule `invalid-super-argument` is enabled by default
```
```
error[invalid-super-argument]: `(int, str, /) -> bool` is an abstract/structural type in `super(<class 'object'>, (int, str, /) -> bool)` call
--> src/mdtest_snippet.py:75:17
|
73 | # error: [invalid-super-argument]
74 | # revealed: Unknown
75 | reveal_type(super(object, z))
| ^^^^^^^^^^^^^^^^
76 |
77 | is_list = g(x)
|
info: rule `invalid-super-argument` is enabled by default
```

View file

@ -0,0 +1,214 @@
---
source: crates/ty_test/src/lib.rs
expression: snapshot
---
---
mdtest name: super.md - Super - Basic Usage - Implicit Super Object
mdtest path: crates/ty_python_semantic/resources/mdtest/class/super.md
---
# Python source files
## mdtest_snippet.py
```
1 | from __future__ import annotations
2 |
3 | class A:
4 | def __init__(self, a: int): ...
5 | @classmethod
6 | def f(cls): ...
7 |
8 | class B(A):
9 | def __init__(self, a: int):
10 | # TODO: Once `Self` is supported, this should be `<super: <class 'B'>, B>`
11 | reveal_type(super()) # revealed: <super: <class 'B'>, Unknown>
12 | reveal_type(super(object, super())) # revealed: <super: <class 'object'>, super>
13 | super().__init__(a)
14 |
15 | @classmethod
16 | def f(cls):
17 | # TODO: Once `Self` is supported, this should be `<super: <class 'B'>, <class 'B'>>`
18 | reveal_type(super()) # revealed: <super: <class 'B'>, Unknown>
19 | super().f()
20 |
21 | super(B, B(42)).__init__(42)
22 | super(B, B).f()
23 | import enum
24 | from typing import Any, Self, Never, Protocol, Callable
25 | from ty_extensions import Intersection
26 |
27 | class BuilderMeta(type):
28 | def __new__(
29 | cls: type[Any],
30 | name: str,
31 | bases: tuple[type, ...],
32 | dct: dict[str, Any],
33 | ) -> BuilderMeta:
34 | # revealed: <super: <class 'BuilderMeta'>, Any>
35 | s = reveal_type(super())
36 | # revealed: Any
37 | return reveal_type(s.__new__(cls, name, bases, dct))
38 |
39 | class BuilderMeta2(type):
40 | def __new__(
41 | cls: type[BuilderMeta2],
42 | name: str,
43 | bases: tuple[type, ...],
44 | dct: dict[str, Any],
45 | ) -> BuilderMeta2:
46 | # revealed: <super: <class 'BuilderMeta2'>, <class 'BuilderMeta2'>>
47 | s = reveal_type(super())
48 | # TODO: should be `BuilderMeta2` (needs https://github.com/astral-sh/ty/issues/501)
49 | # revealed: Unknown
50 | return reveal_type(s.__new__(cls, name, bases, dct))
51 |
52 | class Foo[T]:
53 | x: T
54 |
55 | def method(self: Any):
56 | reveal_type(super()) # revealed: <super: <class 'Foo'>, Any>
57 |
58 | if isinstance(self, Foo):
59 | reveal_type(super()) # revealed: <super: <class 'Foo'>, Any>
60 |
61 | def method2(self: Foo[T]):
62 | # revealed: <super: <class 'Foo'>, Foo[T@Foo]>
63 | reveal_type(super())
64 |
65 | def method3(self: Foo):
66 | # revealed: <super: <class 'Foo'>, Foo[Unknown]>
67 | reveal_type(super())
68 |
69 | def method4(self: Self):
70 | # revealed: <super: <class 'Foo'>, Foo[T@Foo]>
71 | reveal_type(super())
72 |
73 | def method5[S: Foo[int]](self: S, other: S) -> S:
74 | # revealed: <super: <class 'Foo'>, Foo[int]>
75 | reveal_type(super())
76 | return self
77 |
78 | def method6[S: (Foo[int], Foo[str])](self: S, other: S) -> S:
79 | # revealed: <super: <class 'Foo'>, Foo[int]> | <super: <class 'Foo'>, Foo[str]>
80 | reveal_type(super())
81 | return self
82 |
83 | def method7[S](self: S, other: S) -> S:
84 | # error: [invalid-super-argument]
85 | # revealed: Unknown
86 | reveal_type(super())
87 | return self
88 |
89 | def method8[S: int](self: S, other: S) -> S:
90 | # error: [invalid-super-argument]
91 | # revealed: Unknown
92 | reveal_type(super())
93 | return self
94 |
95 | def method9[S: (int, str)](self: S, other: S) -> S:
96 | # error: [invalid-super-argument]
97 | # revealed: Unknown
98 | reveal_type(super())
99 | return self
100 |
101 | def method10[S: Callable[..., str]](self: S, other: S) -> S:
102 | # error: [invalid-super-argument]
103 | # revealed: Unknown
104 | reveal_type(super())
105 | return self
106 |
107 | type Alias = Bar
108 |
109 | class Bar:
110 | def method(self: Alias):
111 | # revealed: <super: <class 'Bar'>, Bar>
112 | reveal_type(super())
113 |
114 | def pls_dont_call_me(self: Never):
115 | # revealed: <super: <class 'Bar'>, Unknown>
116 | reveal_type(super())
117 |
118 | def only_call_me_on_callable_subclasses(self: Intersection[Bar, Callable[..., object]]):
119 | # revealed: <super: <class 'Bar'>, Bar>
120 | reveal_type(super())
121 |
122 | class P(Protocol):
123 | def method(self: P):
124 | # revealed: <super: <class 'P'>, P>
125 | reveal_type(super())
126 |
127 | class E(enum.Enum):
128 | X = 1
129 |
130 | def method(self: E):
131 | match self:
132 | case E.X:
133 | # revealed: <super: <class 'E'>, E>
134 | reveal_type(super())
```
# Diagnostics
```
error[invalid-super-argument]: `S@method7` is not an instance or subclass of `<class 'Foo'>` in `super(<class 'Foo'>, S@method7)` call
--> src/mdtest_snippet.py:86:21
|
84 | # error: [invalid-super-argument]
85 | # revealed: Unknown
86 | reveal_type(super())
| ^^^^^^^
87 | return self
|
info: Type variable `S` has `object` as its implicit upper bound
info: `object` is not an instance or subclass of `<class 'Foo'>`
info: rule `invalid-super-argument` is enabled by default
```
```
error[invalid-super-argument]: `S@method8` is not an instance or subclass of `<class 'Foo'>` in `super(<class 'Foo'>, S@method8)` call
--> src/mdtest_snippet.py:92:21
|
90 | # error: [invalid-super-argument]
91 | # revealed: Unknown
92 | reveal_type(super())
| ^^^^^^^
93 | return self
|
info: Type variable `S` has upper bound `int`
info: `int` is not an instance or subclass of `<class 'Foo'>`
info: rule `invalid-super-argument` is enabled by default
```
```
error[invalid-super-argument]: `S@method9` is not an instance or subclass of `<class 'Foo'>` in `super(<class 'Foo'>, S@method9)` call
--> src/mdtest_snippet.py:98:21
|
96 | # error: [invalid-super-argument]
97 | # revealed: Unknown
98 | reveal_type(super())
| ^^^^^^^
99 | return self
|
info: Type variable `S` has constraints `int, str`
info: `int | str` is not an instance or subclass of `<class 'Foo'>`
info: rule `invalid-super-argument` is enabled by default
```
```
error[invalid-super-argument]: `S@method10` is a type variable with an abstract/structural type as its bounds or constraints, in `super(<class 'Foo'>, S@method10)` call
--> src/mdtest_snippet.py:104:21
|
102 | # error: [invalid-super-argument]
103 | # revealed: Unknown
104 | reveal_type(super())
| ^^^^^^^
105 | return self
|
info: Type variable `S` has upper bound `(...) -> str`
info: rule `invalid-super-argument` is enabled by default
```