`Enum.value` typed as `Any` when using `functools.cache`
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Description
Bug Report
If I define a method with @functools.cache on an Enum, then the type of that Enum's value attr becomes Any. Without the @functools.cache annotation, it gets typed correctly.
Also, this behavior does not occur if you use enum literals - i.e., Foo.BAR.value is typed correctly, but foo.value (for a foo: Foo) is wrong.
To Reproduce
https://mypy-play.net/?mypy=latest&python=3.12&gist=b2a218b8db8367b2ac62dcf583a8c4f7
Expected Behavior
The type assertion in frobnicate() should succeed.
Actual Behavior
The type assertion in frobnicate() fails 😿.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the linked mypy-play reproduction using Python 3.12 and inspect how functools.cache affects the type of Enum.value for a variable typed as the enum. Compare this with the working enum-literal case and use the assertion in frobnicate() as the success criterion. Add a regression test covering the reported behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python
- Domain
- compilers
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 38/100