Pyrefly does not flag invalid return value for method annotated with Self

Describe the Bug

from typing import Self

class Shape:
    def method(self) -> Self:
        return Shape()  # should error: returns Shape, not Self

    @classmethod
    def cls_method(cls) -> Self:
        return Shape()  # should error: returns Shape, not Self

There's already a failing unittest checked in with this example.

Sandbox Link

https://pyrefly.org/sandbox/?project=N4IgZglgNgpgziAXKOBDAdgEwEYHsAeAdAA4CeS4ATrgLYAEALqcROgOZ0Q3G6UN0BlGFDAAddOIDGUVHDiCAFqmIxE4uhrqYYYOjRgMFuTAAo4wsAEo6AWgB8gi2vSbXdSgYCulFwKUqTazoAYjo4I08oTDoYSmpKRHcvH3k-ZRgAGjp0XH4hEXF1TQABaVk4fUNjIo1tXWk4AH1Ko1MG63tHEWc3TQ8Gb19-GECNUPDcSOjY%2BMT%2BwdThrJy8ixAMkE8GaDgSckQQUIBVbagIJjowT3RJbdx0OEKsHUveGlQGRvRPGmxYk3wiVYDA6DjgDASNSSAx8l1EIAAcj8-gk6MB8ABfeHidYgMgeMBQUiEBi0KAUUIABVIBKJYQwOAIdEk90gbG8Hwg90I4lCQhgdAUDAYxDgiAA9OL8ToiYReGxxTB0OLMLhJHBxSz0GyOXdla9KHRUAA3VDQVDYWDM1kQdmUTn3Oi4Yh63biMhVdA2Y2xOBclwAXjo8IAzIQAIwAJmx6BAGI2qFuEB9ADFoDAKGgsHgiGQ40A

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No response

Another case to test - we should not error if the class is final

from typing import Self, final

@final
class Shape:
    def method(self) -> Self:
        return Shape()  # ok

    @classmethod
    def cls_method(cls) -> Self:
        return Shape()  # ok

I've been working on it!

add Self type validation test cases facebook#2304

Add github workflow for v1 issue ranking

This is fixed :D

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Pyrefly does not flag invalid return value for method annotated with Self #2304

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Pyrefly does not flag invalid return value for method annotated with Self #2304

Description

Describe the Bug

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(Only applicable for extension issues) IDE Information

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yangdanny97 commented on Feb 5, 2026

GrimNej commented on Feb 13, 2026

rchen152 commented on Jun 12, 2026

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