[ty] bidirectional type inference using function return type annotations #20528

mtshiba · 2025-09-23T05:57:09Z

Summary

Implements bidirectional type inference using function return type annotations.

This PR was originally proposed to solve astral-sh/ty#1167, but this does not fully resolve it on its own.
Additionally, I believe we need to allow dataclasses to generate their own __new__ methods, use constructor return types for inference, and a mechanism to discard type narrowing like & ~AlwaysFalsy if necessary (at a more general level than this PR).

Test Plan

mdtest/bidirectional.md is added.

…e of expressions in return statements

github-actions · 2025-09-23T05:59:21Z

Diagnostic diff on typing conformance tests

No changes detected when running ty on typing conformance tests ✅

github-actions · 2025-09-23T06:09:30Z

`mypy_primer` results

Changes were detected when running on open source projects

spack (https://github.com/spack/spack)
- lib/spack/spack/installer.py:2185:27: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[Unknown]`, found `set[str] | None`
+ lib/spack/spack/installer.py:2185:27: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[str]`, found `set[str] | None`

werkzeug (https://github.com/pallets/werkzeug)
- src/werkzeug/local.py:511:24: error[invalid-return-type] Return type does not match returned value: expected `T@LocalProxy`, found `~None | Unknown`
+ src/werkzeug/local.py:511:24: error[invalid-return-type] Return type does not match returned value: expected `T@LocalProxy`, found `T@LocalProxy | ~None | Unknown`
+ src/werkzeug/routing/exceptions.py:107:20: error[no-matching-overload] No overload of function `max` matches arguments
- Found 382 diagnostics
+ Found 383 diagnostics

pytest (https://github.com/pytest-dev/pytest)
- testing/python/raises_group.py:33:12: error[invalid-return-type] Return type does not match returned value: expected `RaisesExc[Failed]`, found `RaisesExc[BaseException]`
- Found 490 diagnostics
+ Found 489 diagnostics

aiortc (https://github.com/aiortc/aiortc)
- src/aiortc/codecs/g711.py:65:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[Unknown], None]`
+ src/aiortc/codecs/g711.py:65:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[bytes], None]`
- src/aiortc/codecs/g722.py:73:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[Unknown], None]`
+ src/aiortc/codecs/g722.py:73:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[bytes], None]`
- src/aiortc/codecs/opus.py:73:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[Unknown], None]`
+ src/aiortc/codecs/opus.py:73:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[bytes], int]`, found `tuple[list[bytes], None]`

paasta (https://github.com/yelp/paasta)
- paasta_tools/cli/cmds/mesh_status.py:117:16: error[invalid-return-type] Return type does not match returned value: expected `tuple[int, list[str]]`, found `tuple[Unknown | None, list[Unknown | str]]`
+ paasta_tools/cli/cmds/mesh_status.py:117:16: error[invalid-return-type] Return type does not match returned value: expected `tuple[int, list[str]]`, found `tuple[Unknown | None, list[str]]`
- paasta_tools/tron_tools.py:547:16: error[invalid-return-type] Return type does not match returned value: expected `dict[str, FieldSelectorConfig]`, found `dict[Unknown | str, Unknown | dict[Unknown | str, Unknown | str]]`
+ paasta_tools/tron_tools.py:547:16: error[invalid-return-type] Return type does not match returned value: expected `dict[str, FieldSelectorConfig]`, found `dict[str, FieldSelectorConfig | dict[Unknown | str, Unknown | str]]`
- paasta_tools/utils.py:3416:12: error[invalid-return-type] Return type does not match returned value: expected `InstanceConfigDict`, found `(Unknown & ~None) | dict[str, Any]`
+ paasta_tools/utils.py:3416:12: error[invalid-return-type] Return type does not match returned value: expected `InstanceConfigDict`, found `InstanceConfigDict | (Unknown & ~None) | dict[str, Any]`

pyjwt (https://github.com/jpadilla/pyjwt)
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_signature' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'require' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'strict_aud' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_aud' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_exp' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_iat' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_iss' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_jti' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_nbf' in TypedDict `FullOptions` constructor
+ jwt/api_jwt.py:77:16: error[missing-typed-dict-key] Missing required key 'verify_sub' in TypedDict `FullOptions` constructor
- Found 23 diagnostics
+ Found 33 diagnostics

sockeye (https://github.com/awslabs/sockeye)
- sockeye/data_io.py:1149:62: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `list[tuple[int | float | None, int | float | None]] | None`
+ sockeye/data_io.py:1149:62: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[tuple[int | float | None, int | float | None]]`, found `list[tuple[int | float | None, int | float | None]] | None`
- sockeye/model.py:816:56: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `list[int] | None`
+ sockeye/model.py:816:56: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[int]`, found `list[int] | None`
- test/unit/test_inference.py:177:114: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `list[Any] | None`
+ test/unit/test_inference.py:177:114: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Any]`, found `list[Any] | None`

pydantic (https://github.com/pydantic/pydantic)
- pydantic/_internal/_validators.py:161:16: error[invalid-return-type] Return type does not match returned value: expected `Pattern[bytes]`, found `Pattern[str]`
+ pydantic/_internal/_validators.py:161:16: error[invalid-return-type] Return type does not match returned value: expected `Pattern[bytes]`, found `Pattern[bytes | str]`

pylox (https://github.com/sco1/pylox)
+ pylox/builtins/py_builtins.py:175:32: error[invalid-argument-type] Argument to function `mean` is incorrect: Expected `Iterable[int | float]`, found `dict[Unknown, Unknown] | Unknown | deque[Unknown | None]`
+ pylox/builtins/py_builtins.py:192:34: error[invalid-argument-type] Argument to function `median` is incorrect: Expected `Iterable[int | float]`, found `dict[Unknown, Unknown] | Unknown | deque[Unknown | None]`
+ pylox/builtins/py_builtins.py:216:32: error[invalid-argument-type] Argument to function `mode` is incorrect: Expected `Iterable[int | float]`, found `dict[Unknown, Unknown] | Unknown | deque[Unknown | None]`
+ pylox/builtins/py_builtins.py:326:33: error[invalid-argument-type] Argument to function `stdev` is incorrect: Expected `Iterable[int | float]`, found `dict[Unknown, Unknown] | Unknown | deque[Unknown | None]`
- Found 22 diagnostics
+ Found 26 diagnostics

dragonchain (https://github.com/dragonchain/dragonchain)
- dragonchain/webserver/lib/transactions.py:131:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, str]`, found `dict[Unknown | str, Unknown | None]`
+ dragonchain/webserver/lib/transactions.py:131:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, str]`, found `dict[str, str | Unknown | None]`

urllib3 (https://github.com/urllib3/urllib3)
- src/urllib3/contrib/pyopenssl.py:397:16: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[Any]] | None`, found `dict[Unknown | str, Unknown | tuple[tuple[tuple[str, Unknown]]] | list[tuple[str, str]]]`
+ src/urllib3/contrib/pyopenssl.py:397:16: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[Any]] | None`, found `dict[str, list[Any] | tuple[tuple[tuple[str, Unknown]]] | list[tuple[str, str]]]`

sphinx (https://github.com/sphinx-doc/sphinx)
- sphinx/domains/cpp/_symbol.py:1183:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[Symbol] | None, str]`, found `tuple[list[Unknown], None]`
+ sphinx/domains/cpp/_symbol.py:1183:20: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[Symbol] | None, str]`, found `tuple[list[Symbol | (Unknown & ~None)], None]`

Expression (https://github.com/cognitedata/Expression)
- expression/core/result.py:198:24: error[invalid-return-type] Return type does not match returned value: expected `dict[str, _TSourceOut@Result | _TErrorOut@Result | Literal["ok", "error"]]`, found `dict[Unknown | str, Unknown | str | _TSourceOut@Result]`
- expression/core/result.py:203:24: error[invalid-return-type] Return type does not match returned value: expected `dict[str, _TSourceOut@Result | _TErrorOut@Result | Literal["ok", "error"]]`, found `dict[Unknown | str, Unknown | str | _TErrorOut@Result]`
- expression/extra/option/pipeline.py:91:19: error[invalid-argument-type] Argument to function `reduce` is incorrect: Expected `(def Some[_T1](value: _T1@Some) -> Option[_T1@Some], (Any, /) -> Option[Any], /) -> def Some[_T1](value: _T1@Some) -> Option[_T1@Some]`, found `def reducer(acc: (Any, /) -> Option[Any], fn: (Any, /) -> Option[Any]) -> (Any, /) -> Option[Any]`
- expression/extra/result/pipeline.py:96:19: error[invalid-argument-type] Argument to function `reduce` is incorrect: Expected `(def Ok[_TSource](value: _TSource@Ok) -> Result[_TSource@Ok, Any], (Any, /) -> Result[Any, Any], /) -> def Ok[_TSource](value: _TSource@Ok) -> Result[_TSource@Ok, Any]`, found `def reducer(acc: (Any, /) -> Result[Any, Any], fn: (Any, /) -> Result[Any, Any]) -> (Any, /) -> Result[Any, Any]`
- Found 211 diagnostics
+ Found 207 diagnostics

antidote (https://github.com/Finistere/antidote)
+ tests/lib/interface/test_conditions.py:193:59: error[invalid-argument-type] Argument to bound method `when` is incorrect: Expected `Predicate[Weighted] | Predicate[NeutralWeight] | Weighted | ... omitted 3 union elements`, found `Weight | None`
- Found 300 diagnostics
+ Found 301 diagnostics

freqtrade (https://github.com/freqtrade/freqtrade)
- freqtrade/optimize/optimize_reports/optimize_reports.py:492:9: error[invalid-argument-type] Argument to function `generate_tag_metrics` is incorrect: Expected `Literal["enter_tag", "exit_reason"] | list[Literal["enter_tag", "exit_reason"]]`, found `list[Unknown | str]`
- Found 402 diagnostics
+ Found 401 diagnostics

Tanjun (https://github.com/FasterSpeeding/Tanjun)
- tanjun/commands/menu.py:181:16: error[no-matching-overload] No overload of bound method `__init__` matches arguments
- tanjun/commands/menu.py:308:16: error[no-matching-overload] No overload of bound method `__init__` matches arguments
- Found 115 diagnostics
+ Found 113 diagnostics

xarray (https://github.com/pydata/xarray)
- xarray/backends/scipy_.py:326:16: error[invalid-return-type] Return type does not match returned value: expected `str | ReadBuffer[Unknown] | AbstractDataStore`, found `str | PathLike[Any] | ReadBuffer[Unknown] | ... omitted 3 union elements`
+ xarray/backends/scipy_.py:326:16: error[invalid-return-type] Return type does not match returned value: expected `str | ReadBuffer[Unknown] | AbstractDataStore`, found `str | ReadBuffer[Unknown] | AbstractDataStore | ... omitted 3 union elements`
- xarray/conventions.py:415:17: error[invalid-argument-type] Argument to function `decode_cf_variable` is incorrect: Expected `bool`, found `bool | Mapping[str, bool] | Unknown`
- xarray/conventions.py:416:17: error[invalid-argument-type] Argument to function `decode_cf_variable` is incorrect: Expected `bool`, found `bool | Mapping[str, bool] | Unknown`
- xarray/conventions.py:420:17: error[invalid-argument-type] Argument to function `decode_cf_variable` is incorrect: Expected `bool`, found `bool | (Mapping[str, bool] & ~AlwaysTruthy) | (Unknown & ~AlwaysTruthy)`
- xarray/conventions.py:421:17: error[invalid-argument-type] Argument to function `decode_cf_variable` is incorrect: Expected `bool | None`, found `bool | Mapping[str, bool] | None | Unknown`
- xarray/conventions.py:422:17: error[invalid-argument-type] Argument to function `decode_cf_variable` is incorrect: Expected `bool | CFTimedeltaCoder | None`, found `bool | CFTimedeltaCoder | Mapping[str, bool | CFTimedeltaCoder] | None | Unknown`
+ xarray/conventions.py:406:30: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, Literal[True] | Unknown] | Literal[True]`, found `bool | Mapping[str, bool]`
+ xarray/conventions.py:415:52: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, Literal[True] | Unknown] | Literal[True]`, found `bool | Mapping[str, bool]`
+ xarray/conventions.py:416:49: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, Literal[True] | Unknown] | Literal[True]`, found `bool | Mapping[str, bool]`
+ xarray/conventions.py:418:62: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, Literal[True] | Unknown] | Literal[True]`, found `bool | CFDatetimeCoder | Mapping[str, bool | CFDatetimeCoder]`
+ xarray/conventions.py:421:45: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, None | Unknown] | None`, found `bool | Mapping[str, bool] | None`
+ xarray/conventions.py:422:51: error[invalid-argument-type] Argument to function `_item_or_default` is incorrect: Expected `Mapping[Any, None | Unknown] | None`, found `bool | CFTimedeltaCoder | Mapping[str, bool | CFTimedeltaCoder] | None`
- Found 1611 diagnostics
+ Found 1612 diagnostics

meson (https://github.com/mesonbuild/meson)
- mesonbuild/scripts/symbolextractor.py:221:16: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[str], str]`, found `tuple[list[Unknown | (str & ~AlwaysFalsy)], None]`
+ mesonbuild/scripts/symbolextractor.py:221:16: error[invalid-return-type] Return type does not match returned value: expected `tuple[list[str], str]`, found `tuple[list[str], None]`
- mesonbuild/utils/universal.py:1692:12: error[invalid-return-type] Return type does not match returned value: expected `list[str]`, found `list[Any | Sequence[Any]]`
- Found 886 diagnostics
+ Found 885 diagnostics

pandera (https://github.com/pandera-dev/pandera)
+ tests/mypy/pandas_modules/pandas_dataframe.py:35:12: error[no-matching-overload] No overload of bound method `pipe` matches arguments
- tests/mypy/pandas_modules/pandas_dataframe.py:41:12: error[invalid-return-type] Return type does not match returned value: expected `DataFrame[SchemaOut]`, found `DataFrame[Schema]`
+ tests/mypy/pandas_modules/pandas_dataframe.py:41:12: error[invalid-return-type] Return type does not match returned value: expected `DataFrame[SchemaOut]`, found `DataFrame[SchemaOut] | DataFrame[Schema]`
- Found 1592 diagnostics
+ Found 1593 diagnostics

trio (https://github.com/python-trio/trio)
- src/trio/_tests/test_testing_raisesgroup.py:28:12: error[invalid-return-type] Return type does not match returned value: expected `RaisesExc[AssertionError]`, found `RaisesExc[BaseException]`
- Found 649 diagnostics
+ Found 648 diagnostics

strawberry (https://github.com/strawberry-graphql/strawberry)
+ strawberry/federation/object_type.py:90:9: error[invalid-argument-type] Argument to function `type` is incorrect: Expected `T@_impl_type`, found `T@_impl_type | None`
- Found 381 diagnostics
+ Found 382 diagnostics

hydra-zen (https://github.com/mit-ll-responsible-ai/hydra-zen)
- src/hydra_zen/wrapper/_implementations.py:945:16: error[invalid-return-type] Return type does not match returned value: expected `DataClass_ | type[@Todo] | ListConfig | DictConfig`, found `@Todo | (((...) -> Any) & Top[dict[Unknown, Unknown]]) | (DataClass_ & Top[dict[Unknown, Unknown]]) | ... omitted 8 union elements`
+ src/hydra_zen/wrapper/_implementations.py:945:16: error[invalid-return-type] Return type does not match returned value: expected `DataClass_ | type[@Todo] | ListConfig | DictConfig`, found `@Todo | DataClass_ | type[@Todo] | ... omitted 6 union elements`

openlibrary (https://github.com/internetarchive/openlibrary)
- openlibrary/plugins/upstream/models.py:587:28: error[invalid-return-type] Return type does not match returned value: expected `list[Image]`, found `list[Unknown | (Edition & ~AlwaysTruthy & ~AlwaysFalsy)]`
+ openlibrary/plugins/upstream/models.py:587:28: error[invalid-return-type] Return type does not match returned value: expected `list[Image]`, found `list[Image | (Edition & ~AlwaysTruthy & ~AlwaysFalsy) | (Unknown & ~AlwaysFalsy)]`
- openlibrary/plugins/worksearch/code.py:436:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `list[str] | None`
+ openlibrary/plugins/worksearch/code.py:436:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[str]`, found `list[str] | None`
- openlibrary/plugins/worksearch/code.py:436:61: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `list[str] | None`
+ openlibrary/plugins/worksearch/code.py:436:61: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[str]`, found `list[str] | None`

altair (https://github.com/vega/altair)
+ tests/vegalite/v6/test_theme.py:453:17: error[invalid-key] Invalid key access on TypedDict `StyleConfigIndexKwds`: Unknown key "group-title"
+ tests/vegalite/v6/test_theme.py:454:17: error[invalid-key] Invalid key access on TypedDict `StyleConfigIndexKwds`: Unknown key "guide-label"
+ tests/vegalite/v6/test_theme.py:455:17: error[invalid-key] Invalid key access on TypedDict `StyleConfigIndexKwds`: Unknown key "guide-title"
- Found 1336 diagnostics
+ Found 1339 diagnostics

prefect (https://github.com/PrefectHQ/prefect)
+ src/prefect/server/models/block_documents.py:462:29: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
- Found 3249 diagnostics
+ Found 3250 diagnostics

pandas-stubs (https://github.com/pandas-dev/pandas-stubs)
- tests/indexes/arithmetic/timedeltaindex/test_mul.py:21:12: error[invalid-return-type] Return type does not match returned value: expected `TimedeltaIndex`, found `Index[Any]`
+ tests/indexes/arithmetic/timedeltaindex/test_mul.py:21:12: error[invalid-return-type] Return type does not match returned value: expected `TimedeltaIndex`, found `TimedeltaIndex | Index[Any]`

bokeh (https://github.com/bokeh/bokeh)
- src/bokeh/core/property/alias.py:89:16: error[invalid-return-type] Return type does not match returned value: expected `list[PropertyDescriptor[T@Alias]]`, found `list[Unknown | AliasPropertyDescriptor[Unknown]]`
+ src/bokeh/core/property/alias.py:89:16: error[invalid-return-type] Return type does not match returned value: expected `list[PropertyDescriptor[T@Alias]]`, found `list[PropertyDescriptor[T@Alias] | AliasPropertyDescriptor[Unknown]]`
- src/bokeh/core/property/alias.py:103:16: error[invalid-return-type] Return type does not match returned value: expected `list[PropertyDescriptor[T@DeprecatedAlias]]`, found `list[Unknown | DeprecatedAliasPropertyDescriptor[Unknown]]`
+ src/bokeh/core/property/alias.py:103:16: error[invalid-return-type] Return type does not match returned value: expected `list[PropertyDescriptor[T@DeprecatedAlias]]`, found `list[PropertyDescriptor[T@DeprecatedAlias] | DeprecatedAliasPropertyDescriptor[Unknown]]`
- src/bokeh/layouts.py:117:26: error[invalid-argument-type] Argument to function `_handle_child_sizing` is incorrect: Expected `list[UIElement]`, found `list[UIElement | list[UIElement]]`
- src/bokeh/layouts.py:118:16: error[invalid-argument-type] Argument is incorrect: Expected `list[UIElement]`, found `list[UIElement | list[UIElement]]`
- src/bokeh/layouts.py:152:26: error[invalid-argument-type] Argument to function `_handle_child_sizing` is incorrect: Expected `list[UIElement]`, found `list[UIElement | list[UIElement]]`
- src/bokeh/layouts.py:153:19: error[invalid-argument-type] Argument is incorrect: Expected `list[UIElement]`, found `list[UIElement | list[UIElement]]`
- Found 469 diagnostics
+ Found 465 diagnostics

dd-trace-py (https://github.com/DataDog/dd-trace-py)
- ddtrace/contrib/internal/botocore/services/bedrock.py:303:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[str]]`, found `dict[Unknown | str, Unknown | list[Unknown] | list[Unknown | str | None]]`
+ ddtrace/contrib/internal/botocore/services/bedrock.py:303:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[str]]`, found `dict[str, list[str] | (@Todo & Top[list[Unknown]]) | list[Unknown] | list[Unknown | str | None]]`
- ddtrace/internal/coverage/instrumentation_py3_12.py:119:36: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[Unknown]`, found `tuple[str, ...] | None`
+ ddtrace/internal/coverage/instrumentation_py3_12.py:119:36: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[str]`, found `tuple[str, ...] | None`
- ddtrace/internal/coverage/instrumentation_py3_12.py:132:36: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[Unknown]`, found `tuple[str, ...] | None`
+ ddtrace/internal/coverage/instrumentation_py3_12.py:132:36: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[str]`, found `tuple[str, ...] | None`
- scripts/freshvenvs.py:230:24: error[invalid-return-type] Return type does not match returned value: expected `tuple[str, list[str]]`, found `tuple[None, list[Unknown]]`
+ scripts/freshvenvs.py:230:24: error[invalid-return-type] Return type does not match returned value: expected `tuple[str, list[str]]`, found `tuple[None, list[str]]`
+ tests/contrib/langgraph/conftest.py:344:16: error[missing-typed-dict-key] Missing required key 'which' in TypedDict `State` constructor
- Found 7576 diagnostics
+ Found 7577 diagnostics

ibis (https://github.com/ibis-project/ibis)
+ ibis/examples/gen_registry.py:329:27: warning[possibly-missing-attribute] Attribute `get` on type `dict[str, str] | None` may be missing
- ibis/expr/types/relations.py:4868:37: error[invalid-argument-type] Argument to function `_to_selector` is incorrect: Expected `Sequence[str | Selector | Column] | Selector | Column`, found `list[Iterable[str] | Selector]`
- ibis/util.py:109:16: error[invalid-return-type] Return type does not match returned value: expected `list[V@promote_list]`, found `list[Unknown | (V@promote_list & Top[dict[Unknown, Unknown]]) | (Iterable[V@promote_list] & Top[dict[Unknown, Unknown]])]`
+ ibis/util.py:109:16: error[invalid-return-type] Return type does not match returned value: expected `list[V@promote_list]`, found `list[V@promote_list | (Iterable[V@promote_list] & Top[dict[Unknown, Unknown]])]`
- ibis/util.py:115:16: error[invalid-return-type] Return type does not match returned value: expected `list[V@promote_list]`, found `list[Unknown | (V@promote_list & ~Top[list[Unknown]] & ~Top[dict[Unknown, Unknown]] & ~None) | (Iterable[V@promote_list] & ~Top[list[Unknown]] & ~Top[dict[Unknown, Unknown]])]`
+ ibis/util.py:115:16: error[invalid-return-type] Return type does not match returned value: expected `list[V@promote_list]`, found `list[V@promote_list | (Iterable[V@promote_list] & ~Top[list[Unknown]] & ~Top[dict[Unknown, Unknown]])]`

jax (https://github.com/google/jax)
- jax/_src/pallas/fuser/block_spec.py:933:7: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:933:7: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:963:13: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:963:13: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:1021:18: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:1021:18: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:1080:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:1080:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:1177:7: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:1177:7: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:1336:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:1336:34: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/pallas/fuser/block_spec.py:1578:40: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[Unknown]`, found `Sequence[@Todo | int | None] | None`
+ jax/_src/pallas/fuser/block_spec.py:1578:40: error[invalid-argument-type] Argument to function `__new__` is incorrect: Expected `Iterable[@Todo | int | None]`, found `Sequence[@Todo | int | None] | None`
- jax/_src/tree_util.py:440:29: error[invalid-argument-type] Argument to function `reduce` is incorrect: Expected `(T@tree_reduce & ~Unspecified, Unknown, /) -> T@tree_reduce & ~Unspecified`, found `(T@tree_reduce, Any, /) -> T@tree_reduce`
- Found 2443 diagnostics
+ Found 2442 diagnostics

pandas (https://github.com/pandas-dev/pandas)
- pandas/io/common.py:1167:12: error[invalid-return-type] Return type does not match returned value: expected `tuple[str | BaseBuffer, bool, list[BaseBuffer]]`, found `tuple[_IOWrapper, Literal[True], list[Unknown | _IOWrapper]]`
+ pandas/io/common.py:1167:12: error[invalid-return-type] Return type does not match returned value: expected `tuple[str | BaseBuffer, bool, list[BaseBuffer]]`, found `tuple[_IOWrapper, Literal[True], list[BaseBuffer | _IOWrapper]]`
- pandas/tests/frame/methods/test_replace.py:24:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[int | str]]`, found `dict[Unknown | str, Unknown | list[int] | list[Unknown]]`
+ pandas/tests/frame/methods/test_replace.py:24:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[int | str]]`, found `dict[str, list[int | str] | list[int] | list[Unknown]]`
- pandas/tests/frame/methods/test_replace.py:29:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[int | float | str]]`, found `dict[Unknown | str, Unknown | list[int] | list[Unknown] | list[Unknown | str | int | float]]`
+ pandas/tests/frame/methods/test_replace.py:29:12: error[invalid-return-type] Return type does not match returned value: expected `dict[str, list[int | float | str]]`, found `dict[str, list[int | float | str] | list[int] | list[Unknown]]`

rotki (https://github.com/rotki/rotki)
+ rotkehlchen/assets/asset.py:172:16: error[invalid-return-type] Return type does not match returned value: expected `AssetWithSymbol`, found `AssetWithNameAndType`
+ rotkehlchen/assets/asset.py:184:16: error[invalid-return-type] Return type does not match returned value: expected `EvmToken`, found `CryptoAsset`
+ rotkehlchen/assets/asset.py:190:16: error[invalid-return-type] Return type does not match returned value: expected `SolanaToken`, found `CryptoAsset`
+ rotkehlchen/assets/asset.py:196:16: error[invalid-return-type] Return type does not match returned value: expected `AssetWithOracles`, found `AssetWithNameAndType`
- rotkehlchen/chain/evm/decoding/beefy_finance/decoder.py:251:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[Unknown, Literal["beefy_finance"]]`
- rotkehlchen/chain/evm/decoding/compound/v3/decoder.py:407:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[@Todo, Literal["compound-v3"]]`
- rotkehlchen/chain/evm/decoding/llamazip/decoder.py:81:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[Unknown, Literal["llamazip"]]`
- rotkehlchen/chain/evm/decoding/morpho/decoder.py:335:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[Unknown, Literal["morpho"]]`
- rotkehlchen/chain/evm/decoding/uniswap/v3/decoder.py:419:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[Unknown, Literal["uniswap-v3-router"]]`
- rotkehlchen/chain/evm/decoding/zerox/decoder.py:294:16: error[invalid-return-type] Return type does not match returned value: expected `dict[@Todo, str]`, found `dict[Unknown, Literal["0x"]]`
- rotkehlchen/tests/db/test_db.py:454:20: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[Unknown]`, found `list[EvmToken] | None`
+ rotkehlchen/tests/db/test_db.py:454:20: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `Iterable[EvmToken]`, found `list[EvmToken] | None`
- rotkehlchen/tests/unit/globaldb/test_asset_updates.py:405:9: error[invalid-argument-type] Argument to bound method `_apply_single_version_update` is incorrect: Expected `dict[Asset, Literal["remote", "local"]] | None`, found `dict[Unknown | Asset, Unknown | str]`
- Found 1702 diagnostics
+ Found 1699 diagnostics

Memory usage changes were detected when running on open source projects

sphinx (https://github.com/sphinx-doc/sphinx)
-     memo metadata = ~40MB
+     memo metadata = ~42MB

…ion type

…ith `is_disjoint_from` (#20538) ## Summary I found this bug while working on #20528. The minimum reproducible code is: ```python from __future__ import annotations from typing import NamedTuple from ty_extensions import is_disjoint_from, static_assert class Path(NamedTuple): prev: Path | None key: str static_assert(not is_disjoint_from(Path, Path)) ``` A stack overflow occurs when a nominal instance type inherits from `NamedTuple` and is defined recursively. This PR fixes this bug. ## Test Plan mdtest updated

…ted functions

crates/ty_python_semantic/src/types/generics.rs

github-actions · 2025-09-24T07:46:17Z

`ecosystem-analyzer` results

Lint rule	Added	Removed	Changed
`invalid-argument-type`	12	15	16
`invalid-return-type`	4	11	26
`missing-typed-dict-key`	11	0	0
`invalid-key`	3	0	0
`no-matching-overload`	3	0	0
`possibly-missing-attribute`	1	0	0
`unused-ignore-comment`	1	0	0
Total	35	26	42

AlexWaygood

This looks pretty good to me! Some small comments below. @dcreager and/or @ibraheemdev will probably be better reviewers, though; I haven't done much work on our bidirectional inference yet

crates/ty_python_semantic/resources/mdtest/bidirectional.md

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

crates/ty_python_semantic/src/types/function.rs

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

…iteral::raw_signature`

codspeed-hq · 2025-10-06T17:10:23Z

CodSpeed Performance Report

Merging #20528 will not alter performance

_{Comparing mtshiba:bidi-return-type (e7b5c14) with main (11a9e7e)}

Summary

✅ 21 untouched
⏩ 30 skipped¹

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. ↩

…verloadLiteral::raw_signature`" This reverts commit 9507d72.

crates/ty_python_semantic/resources/mdtest/generics/legacy/functions.md

This reverts commit d1e9455.

mtshiba · 2025-10-07T19:25:29Z

I think I addressed all review comments.

codspeed reports a slight performance regression, but for the same reason as #20635, I believe it is difficult to avoid this.

The ecosystem reports are generally good, some false positive errors are due to TODOs in TypedDict and the unification solver.

carljm · 2025-10-10T23:53:38Z

I think this might need minor updating now that I merged #20806 (since it should fix a test TODO added in that PR)? @ibraheemdev feel free to merge this if it looks ready to you.

ibraheemdev · 2025-10-11T00:34:50Z

This looks great, thanks.

* main: [ty] bidirectional type inference using function return type annotations (#20528) [ty] use type context more aggressively to infer values when constructing a `TypedDict` (#20806)

* dcreager/typevar-identity: [ty] bidirectional type inference using function return type annotations (#20528) [ty] use type context more aggressively to infer values when constructing a `TypedDict` (#20806)

[ty] propagate the annotated return type of functions to the inferenc…

5844c01

…e of expressions in return statements

mtshiba changed the title ~~[ty] propagate the annotated return type of functions to the inference of expressions in return statements~~ [ty] bidirectional type inference using function return type annotations Sep 23, 2025

don't wrap the raw return types of async functions in CoroutineType

c6f798c

AlexWaygood added the ty Multi-file analysis & type inference label Sep 23, 2025

mtshiba added 2 commits September 23, 2025 23:48

improve SpecializationBuilder::infer behavior when formal is a un…

d14dcc8

…ion type

Merge branch 'main' into bidi-return-type

238ebf5

mtshiba mentioned this pull request Sep 23, 2025

[ty] fix stack overflow when comparing recursive NamedTuple types with is_disjoint_from #20538

Merged

mtshiba added 3 commits September 24, 2025 11:04

Merge branch 'main' into bidi-return-type

69e8582

fix nearest_enclosing_function returning incorrect types for decora…

d33ee55

…ted functions

Update bidirectional.md

9622841

mtshiba force-pushed the bidi-return-type branch from d899f83 to 2d882b3 Compare September 24, 2025 07:26

mtshiba commented Sep 24, 2025

View reviewed changes

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

mtshiba marked this pull request as ready for review September 24, 2025 07:28

mtshiba requested review from AlexWaygood, carljm, dcreager and sharkdp as code owners September 24, 2025 07:28

AlexWaygood added the ecosystem-analyzer label Sep 24, 2025

prevent incorrect specializations in SpecializationBuilder::infer

ef75f0a

mtshiba force-pushed the bidi-return-type branch from 2d882b3 to ef75f0a Compare September 24, 2025 08:43

AlexWaygood added ecosystem-analyzer and removed ecosystem-analyzer labels Sep 24, 2025

AlexWaygood reviewed Sep 24, 2025

View reviewed changes

dcreager reviewed Sep 25, 2025

View reviewed changes

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

mtshiba and others added 2 commits September 27, 2025 01:03

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

6c5625b

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

Update crates/ty_python_semantic/resources/mdtest/bidirectional.md

1565280

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

improve bidirectional inference in infer_collection_literal

0249ba2

mtshiba force-pushed the bidi-return-type branch from 25c8ffc to 0249ba2 Compare October 6, 2025 16:34

don't set generic_context on the Signature returned by `OverloadL…

9507d72

…iteral::raw_signature`

mtshiba added 2 commits October 7, 2025 02:12

Revert "don't set generic_context on the Signature returned by `O…

bd5a465

…verloadLiteral::raw_signature`" This reverts commit 9507d72.

Update function.rs

8834fec

mtshiba requested review from dcreager and ibraheemdev October 6, 2025 17:38

ibraheemdev reviewed Oct 6, 2025

View reviewed changes

crates/ty_python_semantic/resources/mdtest/generics/legacy/functions.md Outdated Show resolved Hide resolved

mtshiba added 4 commits October 8, 2025 02:34

improve specialization between unions

d1e9455

Revert "improve specialization between unions"

b5fddbc

This reverts commit d1e9455.

Merge branch 'main' into bidi-return-type

1b42e05

add TypeDict test cases

97c065d

ibraheemdev approved these changes Oct 7, 2025

View reviewed changes

mtshiba added 2 commits October 10, 2025 14:22

Merge branch 'main' into bidi-return-type

7898360

update mdtest

9cea903

AlexWaygood added ecosystem-analyzer and removed ecosystem-analyzer labels Oct 10, 2025

mtshiba mentioned this pull request Oct 10, 2025

[ty] use type context more aggressively to infer values when constructing a TypedDict #20806

Merged

ibraheemdev mentioned this pull request Oct 11, 2025

[ty] Use declared variable types as bidirectional type context #20796

Merged

ibraheemdev added 2 commits October 10, 2025 20:32

Merge branch 'main' into bidi-return-type

db90cda

update tests

e7b5c14

ibraheemdev enabled auto-merge (squash) October 11, 2025 00:34

ibraheemdev merged commit dc64c08 into astral-sh:main Oct 11, 2025
40 checks passed

mtshiba deleted the bidi-return-type branch October 11, 2025 02:52

[ty] bidirectional type inference using function return type annotations #20528

[ty] bidirectional type inference using function return type annotations #20528

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mtshiba commented Sep 23, 2025

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CodSpeed Performance Report

Merging #20528 will not alter performance

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mtshiba commented Oct 7, 2025

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