[ty] Fix visibility of field specifiers when models are nested inside methods by sharkdp · Pull Request #23069 · astral-sh/ruff

sharkdp · 2026-02-04T13:48:01Z

Summary

The right hand side of annotated assignments inside methods of a class are treated as standalone expressions. Therefore, if someone defines a dataclass-transformer model inside a method like this …

class Outer:
    def method(self):
        @create_model
        class Model:
            x: int = field(kw_only=True)
            y: str

… we infer the right hand side of x: int = field(kw_only=True) as a standalone expression. Previously though, we did not set up the TypeInferenceBuilder::dataclass_field_specifiers field in those cases. This meant that field was not recognized as a field-specifier function.

Ecosystem impact

+ tests/test_hooks.py:154:48: error[missing-argument] No argument provided for required parameter `y`
+ tests/test_next_gen.py:142:14: error[unresolved-attribute] Object of type `dataclasses.Field` has no attribute `validator`
+ tests/test_next_gen.py:380:14: error[unresolved-attribute] Object of type `dataclasses.Field` has no attribute `validator`

These are unavoidable, I believe. They would require an attrs plugin. We have similar errors elsewhere already. These new diagnostics only appear because we previously thought that those fields had default values (since we didn't recognize the right hand side as a field-specifier call).

Test Plan

Regression test.

astral-sh-bot · 2026-02-04T13:49:54Z

Typing conformance results

No changes detected ✅

… methods

astral-sh-bot · 2026-02-04T13:54:28Z

`mypy_primer` results

Changes were detected when running on open source projects

attrs (https://github.com/python-attrs/attrs)
+ tests/test_hooks.py:154:48: error[missing-argument] No argument provided for required parameter `y`
+ tests/test_next_gen.py:142:14: error[unresolved-attribute] Object of type `dataclasses.Field` has no attribute `validator`
+ tests/test_next_gen.py:380:14: error[unresolved-attribute] Object of type `dataclasses.Field` has no attribute `validator`
- Found 628 diagnostics
+ Found 631 diagnostics

pydantic (https://github.com/pydantic/pydantic)
- pydantic/_internal/_core_metadata.py:87:54: error[invalid-assignment] Invalid assignment to key "pydantic_js_extra" with declared type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | ((dict[str, Divergent], type[Any], /) -> None)` on TypedDict `CoreMetadata`: value of type `dict[object, object]`
+ pydantic/_internal/_core_metadata.py:87:54: error[invalid-assignment] Invalid assignment to key "pydantic_js_extra" with declared type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | ((dict[str, int | float | str | ... omitted 3 union elements], type[Any], /) -> None)` on TypedDict `CoreMetadata`: value of type `dict[object, object]`
- pydantic/fields.py:949:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:949:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:989:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:989:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1032:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1032:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1072:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1072:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1115:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1115:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1154:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1154:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1194:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`
+ pydantic/fields.py:1194:5: error[invalid-parameter-default] Default value of type `PydanticUndefinedType` is not assignable to annotated parameter type `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`
- pydantic/fields.py:1573:13: error[invalid-argument-type] Argument is incorrect: Expected `dict[str, Divergent] | ((dict[str, Divergent], /) -> None) | None`, found `Top[dict[Unknown, Unknown]] | (((dict[str, Divergent], /) -> None) & ~Top[dict[Unknown, Unknown]]) | None`
+ pydantic/fields.py:1573:13: error[invalid-argument-type] Argument is incorrect: Expected `dict[str, int | float | str | ... omitted 3 union elements] | ((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) | None`, found `Top[dict[Unknown, Unknown]] | (((dict[str, int | float | str | ... omitted 3 union elements], /) -> None) & ~Top[dict[Unknown, Unknown]]) | None`

scikit-build-core (https://github.com/scikit-build/scikit-build-core)
- src/scikit_build_core/build/wheel.py:99:20: error[no-matching-overload] No overload of bound method `__init__` matches arguments
- Found 51 diagnostics
+ Found 50 diagnostics

materialize (https://github.com/MaterializeInc/materialize)
+ misc/python/materialize/cli/mz_workload_anonymize.py:218:9: error[no-matching-overload] No overload of bound method `join` matches arguments
- Found 534 diagnostics
+ Found 535 diagnostics

No memory usage changes detected ✅

astral-sh-bot · 2026-02-04T13:56:43Z

`ecosystem-analyzer` results

Lint rule	Added	Removed	Changed
`not-subscriptable`	96	1	0
`unsupported-operator`	89	0	0
`possibly-missing-attribute`	3	4	36
`no-matching-overload`	0	21	0
`invalid-argument-type`	0	2	7
`invalid-parameter-default`	0	0	7
`invalid-return-type`	0	1	3
`unresolved-attribute`	2	0	2
`invalid-await`	0	2	0
`not-iterable`	0	0	2
`invalid-assignment`	0	0	1
`missing-argument`	1	0	0
`unused-type-ignore-comment`	1	0	0
Total	192	31	58

Full report with detailed diff (timing results)

sharkdp · 2026-02-04T15:03:04Z

crates/ty_python_semantic/src/types/infer/builder.rs

+        fn field_specifiers<'db>(
+            db: &'db dyn Db,
+            index: &'db SemanticIndex<'db>,
+            scope: ScopeId<'db>,
+        ) -> Option<SmallVec<[Type<'db>; NUM_FIELD_SPECIFIERS_INLINE]>> {
+            let enclosing_scope = index.scope(scope.file_scope_id(db));
+            let class_node = enclosing_scope.node().as_class()?;
+            let class_definition = index.expect_single_definition(class_node);
+            let class_literal = infer_definition_types(db, class_definition)
+                .declaration_type(class_definition)
+                .inner_type()
+                .as_class_literal()?
+                .as_static()?;
+
+            class_literal
+                .dataclass_params(db)
+                .map(|params| SmallVec::from(params.field_specifiers(db)))
+                .or_else(|| {
+                    Some(SmallVec::from(
+                        CodeGeneratorKind::from_class(db, class_literal.into(), None)?
+                            .dataclass_transformer_params()?
+                            .field_specifiers(db),
+                    ))
+                })
+        }
+
+        if let Some(specifiers) = field_specifiers(self.db(), self.index, self.scope()) {
+            self.dataclass_field_specifiers = specifiers;
+        }


This has only been moved out into a function.

sharkdp force-pushed the david/field-specifier-fix branch from 5669ab7 to a96f014 Compare February 4, 2026 13:50

[ty] Fix visibility of field specifiers when models are nested inside…

8a2308b

… methods

sharkdp force-pushed the david/field-specifier-fix branch from a96f014 to 8a2308b Compare February 4, 2026 13:50

sharkdp added ty Multi-file analysis & type inference ecosystem-analyzer labels Feb 4, 2026

sharkdp changed the title ~~[ty] Fix visibility of field specifiers when models are nested inside…~~ [ty] Fix visibility of field specifiers when models are nested inside methods Feb 4, 2026

sharkdp commented Feb 4, 2026

View reviewed changes

sharkdp marked this pull request as ready for review February 4, 2026 15:05

sharkdp requested review from AlexWaygood, carljm and dcreager as code owners February 4, 2026 15:05

sharkdp mentioned this pull request Feb 4, 2026

[ty] Add new diagnostic for invalid dataclass field orders #19825

Merged

carljm approved these changes Feb 4, 2026

View reviewed changes

sharkdp merged commit 7b7ea73 into main Feb 4, 2026
51 checks passed

sharkdp deleted the david/field-specifier-fix branch February 4, 2026 16:33

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[ty] Fix visibility of field specifiers when models are nested inside methods#23069

[ty] Fix visibility of field specifiers when models are nested inside methods#23069
sharkdp merged 1 commit intomainfrom
david/field-specifier-fix

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Summary

Ecosystem impact

Test Plan

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sharkdp commented Feb 4, 2026 •

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`mypy_primer` results

`ecosystem-analyzer` results