[ty] emit diagnostics for method definitions and other invalid statements in `TypedDict` class bodies by oconnor663 · Pull Request #22351 · astral-sh/ruff

oconnor663 · 2026-01-03T05:11:27Z

Example:

class Foo(TypedDict):
    42
    a: int = 99
    def baz(self) -> None: ...

error[invalid-typed-dict-statement]: invalid statement in TypedDict class body
 --> test.py:4:5
  |
3 | class Foo(TypedDict):
4 |     42
  |     ^^
5 |     a: int = 99
6 |     def baz(self) -> None: ...
  |
info: Only annotated declarations (`<name>: <type>`) are allowed.
info: rule `invalid-typed-dict-statement` is enabled by default

error[invalid-typed-dict-statement]: TypedDict items cannot have a value
 --> test.py:5:14
  |
3 | class Foo(TypedDict):
4 |     42
5 |     a: int = 99
  |              ^^
6 |     def baz(self) -> None: ...
  |
info: rule `invalid-typed-dict-statement` is enabled by default

error[invalid-typed-dict-statement]: TypedDict classes cannot have methods
 --> test.py:6:5
  |
4 |     42
5 |     a: int = 99
6 |     def baz(self) -> None: ...
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
info: rule `invalid-typed-dict-statement` is enabled by default

…ents in `TypedDict` class bodies

astral-sh-bot · 2026-01-03T05:13:05Z

Diagnostic diff on typing conformance tests

Changes were detected when running ty on typing conformance tests

--- old-output.txt	2026-01-05 19:14:41.071627798 +0000
+++ new-output.txt	2026-01-05 19:14:41.439629687 +0000
@@ -946,6 +946,9 @@
 tuples_type_form.py:15:6: error[invalid-assignment] Object of type `tuple[Literal[1], Literal[""]]` is not assignable to `tuple[int, int]`
 tuples_type_form.py:25:7: error[invalid-assignment] Object of type `tuple[Literal[1]]` is not assignable to `tuple[()]`
 tuples_type_form.py:36:7: error[invalid-assignment] Object of type `tuple[Literal[1], Literal[2], Literal[3], Literal[""]]` is not assignable to `tuple[int, ...]`
+typeddicts_class_syntax.py:29:5: error[invalid-typed-dict-statement] TypedDict class cannot have methods
+typeddicts_class_syntax.py:33:5: error[invalid-typed-dict-statement] TypedDict class cannot have methods
+typeddicts_class_syntax.py:38:5: error[invalid-typed-dict-statement] TypedDict class cannot have methods
 typeddicts_extra_items.py:14:37: error[invalid-key] Unknown key "novel_adaptation" for TypedDict `Movie`: Unknown key "novel_adaptation"
 typeddicts_extra_items.py:15:37: error[invalid-key] Unknown key "year" for TypedDict `Movie`: Unknown key "year"
 typeddicts_extra_items.py:29:5: error[type-assertion-failure] Type `bool` does not match asserted type `str`
@@ -1020,4 +1023,4 @@
 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 1022 diagnostics
+Found 1025 diagnostics

astral-sh-bot · 2026-01-03T05:14:20Z

`mypy_primer` results

Changes were detected when running on open source projects

pydantic (https://github.com/pydantic/pydantic)
- pydantic/fields.py:943:5: 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:943:5: 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:983:5: 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:983:5: 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:1026:5: 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:1026:5: 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:1066:5: 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:1066:5: 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:1109:5: 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:1109:5: 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:1148:5: 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:1148:5: 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:1188:5: 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:1188:5: 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:1567:13: 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:1567:13: 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`

strawberry (https://github.com/strawberry-graphql/strawberry)
- strawberry/sanic/context.py:14:49: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- Found 358 diagnostics
+ Found 357 diagnostics

AutoSplit (https://github.com/Toufool/AutoSplit)
+ src/user_profile.py:50:5: error[invalid-typed-dict-statement] TypedDict class cannot have methods
- Found 62 diagnostics
+ Found 63 diagnostics

xarray (https://github.com/pydata/xarray)
- xarray/core/dataarray.py:5757:16: error[invalid-return-type] Return type does not match returned value: expected `T_Xarray@map_blocks`, found `T_Xarray@map_blocks | DataArray | Dataset`
+ xarray/core/dataarray.py:5757:16: error[invalid-return-type] Return type does not match returned value: expected `T_Xarray@map_blocks`, found `DataArray | Dataset`

prefect (https://github.com/PrefectHQ/prefect)
- src/prefect/deployments/runner.py:795:70: warning[possibly-missing-attribute] Attribute `__name__` may be missing on object of type `Unknown | (((...) -> Any) & ((*args: object, **kwargs: object) -> object))`
+ src/prefect/deployments/runner.py:795:70: warning[possibly-missing-attribute] Attribute `__name__` may be missing on object of type `Unknown | ((...) -> Any)`
+ src/prefect/flow_engine.py:812:32: error[invalid-await] `Unknown | R@FlowRunEngine | Coroutine[Any, Any, R@FlowRunEngine]` is not awaitable
+ src/prefect/flow_engine.py:1401:24: error[invalid-await] `Unknown | R@AsyncFlowRunEngine | Coroutine[Any, Any, R@AsyncFlowRunEngine]` is not awaitable
+ src/prefect/flow_engine.py:1482:43: error[invalid-argument-type] Argument to function `next` is incorrect: Expected `SupportsNext[Unknown]`, found `Unknown | R@run_generator_flow_sync`
+ src/prefect/flow_engine.py:1490:21: warning[possibly-missing-attribute] Attribute `throw` may be missing on object of type `Unknown | R@run_generator_flow_sync`
+ src/prefect/flow_engine.py:1524:44: warning[possibly-missing-attribute] Attribute `__anext__` may be missing on object of type `Unknown | R@run_generator_flow_async`
+ src/prefect/flow_engine.py:1531:25: warning[possibly-missing-attribute] Attribute `throw` may be missing on object of type `Unknown | R@run_generator_flow_async`
- src/prefect/flows.py:286:34: error[unresolved-attribute] Object of type `((**P@Flow) -> R@Flow) & ((*args: object, **kwargs: object) -> object)` has no attribute `__name__`
+ src/prefect/flows.py:286:34: error[unresolved-attribute] Object of type `(**P@Flow) -> R@Flow` has no attribute `__name__`
- src/prefect/flows.py:404:68: error[unresolved-attribute] Object of type `((**P@Flow) -> R@Flow) & ((*args: object, **kwargs: object) -> object)` has no attribute `__name__`
+ src/prefect/flows.py:404:68: error[unresolved-attribute] Object of type `(**P@Flow) -> R@Flow` has no attribute `__name__`
- src/prefect/flows.py:1750:53: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- Found 5527 diagnostics
+ Found 5532 diagnostics

static-frame (https://github.com/static-frame/static-frame)
- static_frame/core/series.py:772:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Series[Any, Any], TVDtype@Series]`, found `InterGetItemILocReduces[TypeBlocks | Batch | SeriesAssign | ... omitted 6 union elements, generic[object]]`
+ static_frame/core/series.py:772:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Series[Any, Any], TVDtype@Series]`, found `InterGetItemILocReduces[Self@iloc | Series[Any, Any], generic[object]]`
- static_frame/core/series.py:4072:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[SeriesHE[Any, Any], TVDtype@SeriesHE]`, found `InterGetItemILocReduces[TypeBlocks | Batch | SeriesAssign | ... omitted 6 union elements, generic[object]]`
+ static_frame/core/series.py:4072:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[SeriesHE[Any, Any], TVDtype@SeriesHE]`, found `InterGetItemILocReduces[Top[Index[Any]] | TypeBlocks | Top[Bus[Any]] | ... omitted 7 union elements, generic[object]]`
- static_frame/core/yarn.py:418:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Yarn[Any], object_]`, found `InterGetItemILocReduces[Top[Index[Any]] | Top[Series[Any, Any]] | Top[Yarn[Any]] | ... omitted 6 union elements, generic[object]]`
+ static_frame/core/yarn.py:418:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Yarn[Any], object_]`, found `InterGetItemILocReduces[Self@iloc | Yarn[Any], generic[object]]`

jax (https://github.com/google/jax)
+ jax/_src/tpu_custom_call.py:128:35: error[invalid-typed-dict-statement] TypedDict item cannot have a value
+ jax/_src/tpu_custom_call.py:130:3: error[invalid-typed-dict-statement] TypedDict class cannot have methods
- Found 2796 diagnostics
+ Found 2798 diagnostics

pandas-stubs (https://github.com/pandas-dev/pandas-stubs)
- pandas-stubs/_typing.pyi:1232:16: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- Found 5156 diagnostics
+ Found 5155 diagnostics

No memory usage changes detected ✅

astral-sh-bot · 2026-01-03T08:02:24Z

`ecosystem-analyzer` results

Lint rule	Added	Removed	Changed
`invalid-return-type`	1	1	8
`invalid-argument-type`	4	0	3
`invalid-assignment`	0	0	5
`possibly-missing-attribute`	3	0	1
`invalid-typed-dict-statement`	3	0	0
`invalid-await`	2	0	0
`unresolved-attribute`	0	0	2
`unused-ignore-comment`	0	2	0
Total	13	3	19

Full report with detailed diff (timing results)

AlexWaygood · 2026-01-03T09:02:45Z

Nice! I think we should allow ... in TypedDict class bodies, though. A strict reading of the spec would imply that they're not allowed, but I think the spec should just be amended here. Other type checkers allow ... in TypedDict class bodies, and it's commonly used in Python code (especially stub files) as an alternative to pass.

crates/ty_python_semantic/resources/mdtest/typed_dict.md

AlexWaygood

LGTM!

crates/ty_python_semantic/resources/mdtest/typed_dict.md

crates/ty_python_semantic/src/types/diagnostic.rs

Co-authored-by: Alex Waygood <[email protected]>

oconnor663 · 2026-01-05T19:13:29Z

(Sorry for all the CI churn here. I've been sloppy about running Clippy etc. before I push today.)

[ty] emit diagnostics for method definitions and other invalid statem…

b9a990e

…ents in `TypedDict` class bodies

oconnor663 requested review from AlexWaygood, MichaReiser, carljm, dcreager and sharkdp as code owners January 3, 2026 05:11

oconnor663 mentioned this pull request Jan 3, 2026

[ty] Remove ClassBase::TypedDict #22346

Closed

AlexWaygood added ty Multi-file analysis & type inference ecosystem-analyzer labels Jan 3, 2026

AlexWaygood reviewed Jan 3, 2026

View reviewed changes

crates/ty_python_semantic/resources/mdtest/typed_dict.md Show resolved Hide resolved

allow ... as equivalent to pass, and test an "attribute docstring"

ea43b86

AlexWaygood approved these changes Jan 5, 2026

View reviewed changes

crates/ty_python_semantic/resources/mdtest/typed_dict.md Outdated Show resolved Hide resolved

crates/ty_python_semantic/src/types/diagnostic.rs Outdated Show resolved Hide resolved

oconnor663 and others added 7 commits January 5, 2026 10:02

items -> item

7b6862f

Co-authored-by: Alex Waygood <[email protected]>

diagnostic description cleanup

b7755e1

Co-authored-by: Alex Waygood <[email protected]>

follow-up changes to "items -> item"

fbaebe8

a little more comment and error message cleanup

473d5a0

one more error message follow-up fix

c73ce1e

clippy fix

5d97d9a

cargo dev generate-all

45187ed

oconnor663 merged commit 922d964 into main Jan 5, 2026
48 checks passed

oconnor663 deleted the typeddict_method_errors branch January 5, 2026 19:28

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[ty] emit diagnostics for method definitions and other invalid statements in `TypedDict` class bodies#22351

[ty] emit diagnostics for method definitions and other invalid statements in `TypedDict` class bodies#22351
oconnor663 merged 9 commits intomainfrom
typeddict_method_errors

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