[ty] Infer type of implicit cls parameter in method bodies#21685
Merged
[ty] Infer type of implicit cls parameter in method bodies#21685
cls parameter in method bodies#21685Conversation
ibraheemdev
requested review from
AlexWaygood,
carljm,
dcreager and
sharkdp
as code owners
Diagnostic diff on typing conformance testsChanges were detected when running ty on typing conformance tests--- old-output.txt 2025-12-03 02:01:47.774206207 +0000
+++ new-output.txt 2025-12-03 02:01:51.357221036 +0000
@@ -513,15 +513,13 @@
generics_self_advanced.py:36:9: error[type-assertion-failure] Type `list[Self@method2]` does not match asserted type `list[typing.Self]`
generics_self_advanced.py:37:9: error[type-assertion-failure] Type `Self@method2` does not match asserted type `typing.Self`
generics_self_advanced.py:38:9: error[type-assertion-failure] Type `Self@method2` does not match asserted type `Unknown`
-generics_self_advanced.py:42:9: error[type-assertion-failure] Type `type[Self@method3]` does not match asserted type `Unknown`
-generics_self_advanced.py:43:9: error[type-assertion-failure] Type `list[Self@method3]` does not match asserted type `Unknown`
-generics_self_advanced.py:44:9: error[type-assertion-failure] Type `Self@method3` does not match asserted type `Unknown`
+generics_self_advanced.py:43:9: error[type-assertion-failure] Type `list[Self@method3]` does not match asserted type `list[typing.Self]`
+generics_self_advanced.py:44:9: error[type-assertion-failure] Type `Self@method3` does not match asserted type `typing.Self`
generics_self_advanced.py:45:9: error[type-assertion-failure] Type `Self@method3` does not match asserted type `Unknown`
generics_self_attributes.py:26:33: error[invalid-argument-type] Argument is incorrect: Expected `typing.Self | None`, found `LinkedList[int]`
generics_self_attributes.py:29:5: error[invalid-assignment] Object of type `OrdinalLinkedList` is not assignable to attribute `next` of type `typing.Self | None`
generics_self_attributes.py:32:5: error[invalid-assignment] Object of type `LinkedList[int]` is not assignable to attribute `next` of type `typing.Self | None`
generics_self_basic.py:20:16: error[invalid-return-type] Return type does not match returned value: expected `Self@method2`, found `Shape`
-generics_self_basic.py:27:9: error[type-assertion-failure] Type `type[Self@from_config]` does not match asserted type `Unknown`
generics_self_basic.py:33:16: error[invalid-return-type] Return type does not match returned value: expected `Self@cls_method2`, found `Shape`
generics_self_basic.py:54:1: error[type-assertion-failure] Type `Shape` does not match asserted type `Unknown`
generics_self_basic.py:55:1: error[type-assertion-failure] Type `Circle` does not match asserted type `Unknown`
@@ -1029,4 +1027,4 @@
typeddicts_usage.py:28:17: error[missing-typed-dict-key] Missing required key 'name' in TypedDict `Movie` constructor
typeddicts_usage.py:28:18: error[invalid-key] Unknown key "title" for TypedDict `Movie`: Unknown key "title"
typeddicts_usage.py:40:24: error[invalid-type-form] The special form `typing.TypedDict` is not allowed in type expressions
-Found 1031 diagnostics
+Found 1029 diagnostics
|
|
CodSpeed Performance ReportMerging #21685 will degrade performances by 11.61%Comparing Summary
Benchmarks breakdown
|
|
| Lint rule | Added | Removed | Changed |
|---|---|---|---|
invalid-argument-type |
69 | 18 | 77 |
unresolved-attribute |
85 | 0 | 0 |
unused-ignore-comment |
0 | 80 | 0 |
possibly-missing-attribute |
48 | 0 | 0 |
invalid-return-type |
34 | 1 | 5 |
unknown-argument |
39 | 0 | 0 |
invalid-assignment |
38 | 0 | 0 |
missing-argument |
10 | 0 | 0 |
parameter-already-assigned |
8 | 0 | 0 |
no-matching-overload |
7 | 0 | 0 |
too-many-positional-arguments |
5 | 0 | 0 |
unsupported-operator |
5 | 0 | 0 |
not-iterable |
2 | 0 | 0 |
unsupported-base |
0 | 2 | 0 |
deprecated |
1 | 0 | 0 |
invalid-context-manager |
1 | 0 | 0 |
invalid-type-form |
1 | 0 | 0 |
| Total | 353 | 101 | 82 |
|
Member
|
Here's a minimal repro of one of the new diagnostics on from typing import Callable, Any
def needs_a_callable(x: Callable[[Any], Any] | Callable[[Any, object], Any]): ...
class F:
def __init__(self, arg) -> None: ...
def f[T: F](x: T):
needs_a_callable(type(x))It looks like we might not be implementing assignability correctly for |
Member
|
The artigraph diagnostic in |
Member
|
The new attrs diagnostics are the same as astral-sh/ty#1425, but for attrs rather than pydantic this time. We don't recognise the assignments in the class body of |
Member
|
comtypes looks like it's doing some highly dynamic stuff that I don't think we should be expected to understand right now. The new diagnostics in The new diagnostics in |
Member
|
Here's a minimal repro for the diagnostic on from typing import Iterable, Iterator, Self
class chain[T]:
def __new__(cls, *its: Iterable[T]): ...
def __iter__(self) -> Self:
return self
def __next__(self) -> T:
raise NotImplementedError
class Symbol:
@classmethod
def g(cls) -> list[Symbol]:
return list(chain((cls(),), (cls(),))) # error here...
# error [invalid-argument-type] "Argument to bound method `__init__` is incorrect: Expected `Iterable[Symbol]`, found `chain[Self@from_code]`"
def f[T: Symbol](x: type[T]) -> list[Symbol]:
return list(chain((x(),), (x(),))) # ... but no error here? |
Member
Author
|
That last one may be an issue with how we treat class Symbol:
@classmethod
def f(cls) -> list[Symbol]:
y = chain((cls(),), (cls(),))
reveal_type(y) # chain[Self@g]
return list(y) # error[invalid-argument-type]
def g(self) -> list[Symbol]:
y = chain((self,), (self,))
reveal_type(y) # chain[Self@g]
return list(y) # error[invalid-argument-type]
def f[T: Symbol](x: type[T]) -> list[Symbol]:
y = chain((x(),), (x(),))
reveal_type(y) # chain[T@g]
return list(y) # ok
def g[T: Symbol](x: T) -> list[Symbol]:
y = chain((x,), (x,))
reveal_type(y) # chain[T@g]
return list(y) # ok |
pull bot
pushed a commit
to psy-repos-rust/ruff
that referenced
this pull request
Dec 1, 2025
## Summary Resolves astral-sh#21685 (comment).
ibraheemdev
force-pushed
the
ibraheem/implicit-cls-body
branch
from
2ff8549 to
b691fbc
Compare
carljm
approved these changes
Dec 10, 2025
Contributor
carljm
left a comment
carljm
left a comment
There was a problem hiding this comment.
This looks good to me. I filed astral-sh/ty#1831 for the assignability-to-union-of-callables issue, but I don't think it should block landing this PR, either.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Extends #20922 to infer unannotated
clsparameters astype[Self]in method bodies.Part of astral-sh/ty#159.