"Rename symbol" does not change string slot listed in `__slots__` even if it is a simple assignment

[jonathandung]

Maybe this should be listed in #1546?

[MichaReiser]

I think this is #2464. Or what do you mean by simple assignment?

[AlexWaygood]

I think @jonathandung is saying that if he right-clicked on self.a and asked for it to be renamed to b, he'd want the string in the __slots__ variable updated at the same time.

class Foo:
    __slots__ = ("a",)

    def __init__(self):
        self.a = 42

Pyright does this. It's similar to #2464, but different: #2464 is about __all__ and symbols in the global scope, whereas this is about __slots__ and instance attributes. It's related to #1268 as well as #2464

[MichaReiser]

Lol, slots not all. Sorry. All I saw was dunder something :)

[jonathandung]

Yes. I only reported this issue because when using the VS Code Pylance extension with the Python language integration previously, I would get the symbol in __slots__ renamed, which led me to incorrectly think the behaviour was provided by the Python language extension.

[SuryanshSS1011]

Hi, I'd like to take this on, and here is what I am planning to do:

1. Detect __slots__ string literals syntactically in the references visitor (crates/ty_ide/src/references.rs). When the visitor enters an ExprStringLiteral whose value matches the rename target and whose ancestors are a __slots__ = <container literal> assignment inside a class body, we emit a ReferenceTarget for the string's inner range.

2. Verify class-match by walking the scope ancestors of each target definition up to its enclosing class scope, and comparing against the __slots__-owning class.

Scope I am planning to support for v1:

• __slots__ = ("a", "b") (tuple)
• __slots__ = ["a", "b"] (list)
• __slots__ = {"a", "b"} (set)
• __slots__ = {"a": "...", "b": "..."} (dict, just the keys)

Out of scope for v1:

• Dynamic __slots__ (e.g. __slots__ = tuple(...) or __slots__ = some_var)
• f-strings or concatenated string literals inside the container
• Cross-class __slots__ (each class's __slots__ only matches that class's own instance attributes)

I have two questions specifically before I start:

1. Does the same-class-only restriction match what you want? Pyright also only matches the same class as far as I can tell.
2. For the dict form, the keys are the slot names and the values are typically docstrings. Could you confirm you only want keys?

Happy to PR once this sounds right.

[jonathandung]

Having used Pylance before, limiting the renaming to the class makes sense to me. It would be nice if the values could be preserved exactly as they were for a dictionary as __slots__, such that only a key is changed.

[SuryanshSS1011]

Thanks @jonathandung! That matches exactly what I had in mind. Still waiting for a maintainer confirm before I start.

[SuryanshSS1011]

Opened a PR for this: astral-sh/ruff#26438. It renames the matching __slots__ string when you rename an attribute, scoped to the same class, covering tuple/list/set/dict-key slots. I went ahead with the same-class + dict-keys-only scope from the discussion above. Happy to adjust if maintainers want it narrower or wider.