[ty] Infer `TypedDict` types with >=1 required key as being always truthy by AlexWaygood · Pull Request #22808 · astral-sh/ruff

AlexWaygood · 2026-01-22T18:21:08Z

Summary

This fixes the symptom described in astral-sh/ty#2591. It doesn't fix the underlying cause, which is that we only run the invalid-key check currently on TypedDict types, not on intersections that include TypedDict types. But it seems good to avoid complex intersection types where possible anyway, and this change achieves that.

Test Plan

Mdtests added

…uthy

charliermarsh

Nice.

astral-sh-bot · 2026-01-22T18:22:46Z

Typing conformance results

No changes detected ✅

astral-sh-bot · 2026-01-22T18:24:05Z

`mypy_primer` results

Changes were detected when running on open source projects

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`
- pydantic/json_schema.py:2858:16: error[invalid-return-type] Return type does not match returned value: expected `PlainSerializerFunctionSerSchema | None`, found `(SimpleSerSchema & ~AlwaysFalsy) | (PlainSerializerFunctionSerSchema & ~AlwaysFalsy) | (WrapSerializerFunctionSerSchema & ~AlwaysFalsy) | ... omitted 5 union elements`
+ pydantic/json_schema.py:2858:16: error[invalid-return-type] Return type does not match returned value: expected `PlainSerializerFunctionSerSchema | None`, found `SimpleSerSchema | PlainSerializerFunctionSerSchema | WrapSerializerFunctionSerSchema | ... omitted 5 union elements`

discord.py (https://github.com/Rapptz/discord.py)
- discord/abc.py:1815:25: error[no-matching-overload] No overload of function `__new__` matches arguments
- discord/activity.py:887:54: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- discord/activity.py:891:39: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- discord/scheduled_event.py:150:63: error[invalid-argument-type] Argument to function `store_user` is incorrect: Argument type `User & ~AlwaysFalsy` does not satisfy upper bound `ConnectionState[ClientT@ConnectionState]` of type variable `Self`
+ discord/scheduled_event.py:150:63: error[invalid-argument-type] Argument to function `store_user` is incorrect: Argument type `User` does not satisfy upper bound `ConnectionState[ClientT@ConnectionState]` of type variable `Self`
- discord/sticker.py:420:60: error[invalid-argument-type] Argument to function `store_user` is incorrect: Argument type `User & ~AlwaysFalsy` does not satisfy upper bound `ConnectionState[ClientT@ConnectionState]` of type variable `Self`
+ discord/sticker.py:420:60: error[invalid-argument-type] Argument to function `store_user` is incorrect: Argument type `User` does not satisfy upper bound `ConnectionState[ClientT@ConnectionState]` of type variable `Self`
- Found 539 diagnostics
+ Found 536 diagnostics

meson (https://github.com/mesonbuild/meson)
- mesonbuild/interpreter/compiler.py:737:18: error[invalid-assignment] Object of type `(ExtractRequired & ~AlwaysFalsy) | dict[Unknown | str, Unknown | bool]` is not assignable to `ExtractRequired | None`
+ mesonbuild/interpreter/compiler.py:737:18: error[invalid-assignment] Object of type `ExtractRequired | dict[Unknown | str, Unknown | bool]` is not assignable to `ExtractRequired | None`
- mesonbuild/interpreter/compiler.py:844:18: error[invalid-assignment] Object of type `(ExtractRequired & ~AlwaysFalsy) | dict[Unknown | str, Unknown | bool]` is not assignable to `ExtractRequired | None`
+ mesonbuild/interpreter/compiler.py:844:18: error[invalid-assignment] Object of type `ExtractRequired | dict[Unknown | str, Unknown | bool]` is not assignable to `ExtractRequired | None`

prefect (https://github.com/PrefectHQ/prefect)
- src/integrations/prefect-dbt/prefect_dbt/core/settings.py:94:28: error[invalid-assignment] Object of type `dict[str, Any] | int | T@resolve_block_document_references | ... omitted 4 union elements` is not assignable to `dict[str, Any]`
+ src/integrations/prefect-dbt/prefect_dbt/core/settings.py:94:28: error[invalid-assignment] Object of type `T@resolve_block_document_references | dict[str, Any]` is not assignable to `dict[str, Any]`
- src/integrations/prefect-dbt/prefect_dbt/core/settings.py:99:28: error[invalid-assignment] Object of type `int | T@resolve_variables | float | ... omitted 4 union elements` is not assignable to `dict[str, Any]`
+ src/integrations/prefect-dbt/prefect_dbt/core/settings.py:99:28: error[invalid-assignment] Object of type `T@resolve_variables | dict[str, Any]` is not assignable to `dict[str, Any]`
- src/prefect/cli/deploy/_core.py:86:21: error[invalid-assignment] Object of type `dict[str, Any] | int | T@resolve_block_document_references | ... omitted 4 union elements` is not assignable to `dict[str, Any]`
+ src/prefect/cli/deploy/_core.py:86:21: error[invalid-assignment] Object of type `T@resolve_block_document_references | dict[str, Any]` is not assignable to `dict[str, Any]`
- src/prefect/cli/deploy/_core.py:87:21: error[invalid-assignment] Object of type `int | T@resolve_variables | float | ... omitted 4 union elements` is not assignable to `dict[str, Any]`
+ src/prefect/cli/deploy/_core.py:87:21: error[invalid-assignment] Object of type `T@resolve_variables` is not assignable to `dict[str, Any]`
- src/prefect/deployments/steps/core.py:137:38: error[invalid-argument-type] Argument is incorrect: Expected `T@resolve_variables`, found `dict[str, Any] | int | T@resolve_block_document_references | ... omitted 4 union elements`
+ src/prefect/deployments/steps/core.py:137:38: error[invalid-argument-type] Argument is incorrect: Expected `T@resolve_variables`, found `T@resolve_block_document_references | dict[str, Any]`
- src/prefect/utilities/templating.py:320:13: error[invalid-assignment] Invalid subscript assignment with key of type `object` and value of type `dict[str, Any] | int | T@resolve_block_document_references | ... omitted 4 union elements` on object of type `dict[str, Any]`
+ src/prefect/utilities/templating.py:320:13: error[invalid-assignment] Invalid subscript assignment with key of type `object` and value of type `T@resolve_block_document_references | dict[str, Any]` on object of type `dict[str, Any]`
- src/prefect/utilities/templating.py:323:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_block_document_references | dict[str, Any]`, found `list[Unknown | dict[str, Any] | int | ... omitted 5 union elements]`
+ src/prefect/utilities/templating.py:323:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_block_document_references | dict[str, Any]`, found `list[Unknown | T@resolve_block_document_references | dict[str, Any]]`
- src/prefect/utilities/templating.py:437:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_variables`, found `dict[object, Unknown | int | T@resolve_variables | ... omitted 5 union elements]`
+ src/prefect/utilities/templating.py:437:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_variables`, found `dict[object, Unknown | T@resolve_variables]`
- src/prefect/utilities/templating.py:442:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_variables`, found `list[Unknown | int | T@resolve_variables | ... omitted 5 union elements]`
+ src/prefect/utilities/templating.py:442:16: error[invalid-return-type] Return type does not match returned value: expected `T@resolve_variables`, found `list[Unknown | T@resolve_variables]`
- src/prefect/workers/base.py:232:13: error[invalid-argument-type] Argument is incorrect: Expected `T@resolve_variables`, found `dict[str, Any] | int | T@resolve_block_document_references | ... omitted 4 union elements`
+ src/prefect/workers/base.py:232:13: error[invalid-argument-type] Argument is incorrect: Expected `T@resolve_variables`, found `T@resolve_block_document_references | dict[str, Any]`
- src/prefect/workers/base.py:234:20: error[invalid-argument-type] Argument expression after ** must be a mapping type: Found `int | T@resolve_variables | float | ... omitted 4 union elements`
+ src/prefect/workers/base.py:234:20: error[invalid-argument-type] Argument expression after ** must be a mapping type: Found `T@resolve_variables`

static-frame (https://github.com/static-frame/static-frame)
- static_frame/core/bus.py:675:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Bus[Any], object_]`, found `InterGetItemILocReduces[Bus[Any] | Bottom[Index[Any]] | Bottom[Series[Any, Any]] | ... omitted 7 union elements, object_ | Self@iloc]`
+ static_frame/core/bus.py:675:16: error[invalid-return-type] Return type does not match returned value: expected `InterGetItemILocReduces[Bus[Any], object_]`, found `InterGetItemILocReduces[Bus[Any] | IndexHierarchy | TypeBlocks | ... omitted 7 union elements, object_ | Self@iloc]`
- 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[Series[Any, Any] | IndexHierarchy | TypeBlocks | ... omitted 7 union elements, TVDtype@Series]`
+ 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[Series[Any, Any] | Bottom[Index[Any]] | ndarray[Never, Never] | ... omitted 7 union elements, TVDtype@Series]`
- 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[Bottom[Series[Any, Any]] | IndexHierarchy | TypeBlocks | ... omitted 8 union elements, TVDtype@SeriesHE]`
+ 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[Bottom[Series[Any, Any]] | Bottom[Index[Any]] | TypeBlocks | ... omitted 8 union elements, TVDtype@SeriesHE]`
- 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[Yarn[Any] | IndexHierarchy | TypeBlocks | ... omitted 7 union elements, 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[Yarn[Any] | Bottom[Index[Any]] | Bottom[Series[Any, Any]] | ... omitted 7 union elements, object_]`

core (https://github.com/home-assistant/core)
- homeassistant/components/energy/sensor.py:180:64: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- homeassistant/components/esphome/encryption_key_storage.py:49:13: error[invalid-assignment] Object of type `(Unknown & ~AlwaysFalsy) | (EncryptionKeyData & ~AlwaysFalsy) | dict[Unknown | str, Unknown | dict[Unknown, Unknown]]` is not assignable to attribute `_data` of type `EncryptionKeyData | None`
+ homeassistant/components/esphome/encryption_key_storage.py:49:13: error[invalid-assignment] Object of type `(Unknown & ~AlwaysFalsy) | EncryptionKeyData | dict[Unknown | str, Unknown | dict[Unknown, Unknown]]` is not assignable to attribute `_data` of type `EncryptionKeyData | None`
+ homeassistant/components/todoist/calendar.py:520:55: error[invalid-argument-type] Argument is incorrect: Expected `date`, found `datetime | None`

No memory usage changes detected ✅

codspeed-hq · 2026-01-22T18:37:02Z

CodSpeed Performance Report

Merging this PR will improve performance by 5.5%

_{Comparing alex/td-truthy (b02da42) with main (b7de434)}

Summary

⚡ 1 improved benchmark
✅ 22 untouched benchmarks
⏩ 30 skipped benchmarks¹

Performance Changes

	Mode	Benchmark	`BASE`	`HEAD`	Efficiency
⚡	WallTime	`pydantic`	7.7 s	7.3 s	+5.5%

30 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

AlexWaygood · 2026-01-22T18:37:25Z

yesssss I was hoping that might happen!

[ty] Infer TypedDict types with >=1 required key as being always tr…

b02da42

…uthy

AlexWaygood requested review from carljm, dcreager and sharkdp as code owners January 22, 2026 18:21

AlexWaygood added the ty Multi-file analysis & type inference label Jan 22, 2026

charliermarsh approved these changes Jan 22, 2026

View reviewed changes

AlexWaygood mentioned this pull request Jan 22, 2026

invalid-key not detected for intersections that include TypedDicts astral-sh/ty#2591

Closed

AlexWaygood merged commit 4c7d1f5 into main Jan 22, 2026
50 checks passed

AlexWaygood deleted the alex/td-truthy branch January 22, 2026 18:37

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[ty] Infer `TypedDict` types with >=1 required key as being always truthy#22808

[ty] Infer `TypedDict` types with >=1 required key as being always truthy#22808
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mypy_primer results

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codspeed-hq bot commented Jan 22, 2026

CodSpeed Performance Report

Merging this PR will improve performance by 5.5%

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`mypy_primer` results