Skip to content

[ty] Point to an overload with an invalid @final decoator when emitting invalid-overload errors for invalid @final decorators#22812

Merged
AlexWaygood merged 1 commit intomainfrom
alex/final-overload-error
Jan 22, 2026
Merged

[ty] Point to an overload with an invalid @final decoator when emitting invalid-overload errors for invalid @final decorators#22812
AlexWaygood merged 1 commit intomainfrom
alex/final-overload-error

Conversation

@AlexWaygood
Copy link
Member

@AlexWaygood AlexWaygood commented Jan 22, 2026 •
edited
Loading

Summary

Currently if you have this in a stub file:

from typing_extensions import final, overload

class Foo:
    @overload
    def method3(self, x: int) -> int: ...
    @final
    @overload
    def method3(self, x: str) -> int: ...
    @overload
    @final
    def method3(self, x: bytes) -> bytes: ...
    @overload
    def method3(self, x: bytearray) -> bytearray: ...

then ty correctly emits two invalid-overload errors complaining that only the first overload should be decorated with @final. But both diagnostics are incorrectly attached to the last overload (which isn't actually decorated with @final at all!) rather than overloads 2 and 3 respectively.

Test Plan

Snapshots 'n' mdtests

@AlexWaygood
[ty] Point to an overload with an invalid @final decoator when emit…
865daa1 
…ting `invalid-overload` errors for invalid `@final` decorators
@AlexWaygood AlexWaygood added the ty Multi-file analysis & type inference label Jan 22, 2026
@astral-sh-bot
Copy link

astral-sh-bot bot commented Jan 22, 2026

Typing conformance results improved 🎉

The percentage of diagnostics emitted that were expected errors increased from 77.47% to 77.59%. The percentage of expected errors that received a diagnostic increased from 60.67% to 60.76%.

Summary

Metric Old New Diff Outcome
True Positives 674 675 +1 ⏫ (✅)
False Positives 196 195 -1 ⏬ (✅)
False Negatives 437 436 -1 ⏬ (✅)
Total Diagnostics 870 870 +0
Precision 77.47% 77.59% +0.11% ⏫ (✅)
Recall 60.67% 60.76% +0.09% ⏫ (✅)

True positives added

Details
Location Name Message
overloads_definitions_stub.pyi:73:9 invalid-overload @final decorator should be applied only to the first overload

False positives removed

Details
Location Name Message
overloads_definitions_stub.pyi:76:9 invalid-overload @final decorator should be applied only to the first overload

@AlexWaygood
Copy link
Member Author

AlexWaygood commented Jan 22, 2026

Truly the lowest hanging of fruit

@AlexWaygood AlexWaygood marked this pull request as ready for review January 22, 2026 20:17
@astral-sh-bot
Copy link

astral-sh-bot bot commented Jan 22, 2026

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`

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 47 diagnostics
+ Found 46 diagnostics

rotki (https://github.com/rotki/rotki)
- rotkehlchen/chain/decoding/tools.py:96:44: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- rotkehlchen/chain/decoding/tools.py:99:13: error[invalid-argument-type] Argument to function `decode_transfer_direction` is incorrect: Expected `Sequence[A@BaseDecoderTools]`, found `Unknown | tuple[BTCAddress, ...] | tuple[ChecksumAddress, ...] | tuple[SubstrateAddress, ...] | tuple[SolanaAddress, ...]`
- rotkehlchen/chain/decoding/tools.py:100:62: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
+ rotkehlchen/chain/decoding/tools.py:97:13: error[invalid-argument-type] Argument to function `decode_transfer_direction` is incorrect: Expected `BTCAddress | ChecksumAddress | SubstrateAddress | SolanaAddress`, found `A@BaseDecoderTools`
+ rotkehlchen/chain/decoding/tools.py:98:13: error[invalid-argument-type] Argument to function `decode_transfer_direction` is incorrect: Expected `BTCAddress | ChecksumAddress | SubstrateAddress | SolanaAddress | None`, found `A@BaseDecoderTools | None`
- Found 2050 diagnostics
+ Found 2049 diagnostics

core (https://github.com/home-assistant/core)
- homeassistant/util/variance.py:47:12: error[invalid-return-type] Return type does not match returned value: expected `(**_P@ignore_variance) -> _R@ignore_variance`, found `_Wrapped[_P@ignore_variance, int | _R@ignore_variance | float | datetime, _P@ignore_variance, _R@ignore_variance | int | float | datetime]`
- Found 14466 diagnostics
+ Found 14465 diagnostics

No memory usage changes detected ✅

charliermarsh
charliermarsh approved these changes Jan 22, 2026
View reviewed changes
Copy link
Member

@charliermarsh charliermarsh left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Very nice.

@AlexWaygood AlexWaygood merged commit 9943094 into main Jan 22, 2026
50 checks passed
@AlexWaygood AlexWaygood deleted the alex/final-overload-error branch January 22, 2026 20:57
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Reviewers

@charliermarsh charliermarsh charliermarsh approved these changes

@carljm carljm Awaiting requested review from carljm carljm is a code owner

@sharkdp sharkdp Awaiting requested review from sharkdp sharkdp is a code owner

@dcreager dcreager Awaiting requested review from dcreager dcreager is a code owner

Assignees

No one assigned

Labels

ty Multi-file analysis & type inference

Projects

None yet

Milestone

No milestone

Development

Successfully merging this pull request may close these issues.

2 participants

@AlexWaygood @charliermarsh