David Peter 1fe958c694 [ty] Implicit type aliases: Support for PEP 604 unions (#21195) ...

## Summary

Add support for implicit type aliases that use PEP 604 unions:
```py
IntOrStr = int | str

reveal_type(IntOrStr)  # UnionType

def _(int_or_str: IntOrStr):
    reveal_type(int_or_str)  # int | str
```

## Typing conformance

The changes are either removed false positives, or new diagnostics due
to known limitations unrelated to this PR.

## Ecosystem impact

Spot checked, a mix of true positives and known limitations.

## Test Plan

New Markdown tests.

2025-11-03 21:50:25 +01:00

..

annotations

[ty] Implicit type aliases: Support for PEP 604 unions (#21195)

2025-11-03 21:50:25 +01:00

assignment

[ty] support subscripting typing.Literal with a type alias (#21207)

2025-11-02 12:39:55 -05:00

binary

[ty] Sync vendored typeshed stubs (#20876)

2025-10-15 11:13:32 +02:00

boolean

Revert "[ty] Better control flow for boolean expressions that are inside if (#18010)" (#18150)

2025-05-17 08:27:32 -04:00

boundness_declaredness

[ty] Reformulation of public symbol inference test suite (#20667)

2025-10-01 14:26:17 +02:00

call

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

class

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

comparison

[ty] detect cycles in binary comparison inference (#20446)

2025-09-17 09:45:25 +02:00

comprehensions

[ty] Type inference for comprehensions (#20962)

2025-11-02 14:35:33 +01:00

conditional

[ty] Support as-patterns in reachability analysis (#19728)

2025-08-04 20:13:50 +02:00

dataclasses

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

declaration

[ty] Format conflicting types as an enumeration (#18956)

2025-06-26 14:29:33 +02:00

diagnostics

[ty] continue and break statements outside loops are syntax errors (#20944)

2025-10-17 17:13:40 +00:00

directives

[ty] Use annotated parameters as type context (#20635)

2025-10-03 17:14:51 -04:00

doc

ty_python_semantic: add union type context to function call type errors

2025-05-09 13:40:51 -04:00

exception

[ty] Filter out revealed-type and undefined-reveal diagnostics from mdtest snapshots (#20820)

2025-10-12 18:39:32 +00:00

expression

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

function

[ty] don't union in default type for annotated parameters (#21208)

2025-11-02 18:21:54 -05:00

generics

[ty] Prefer exact matches when solving constrained type variables (#21165)

2025-10-31 10:58:09 -04:00

ide_support

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

import

[ty] prefer submodule over module __getattr__ in from-imports (#21260)

2025-11-03 15:24:01 -05:00

literal

[ty] Type inference for comprehensions (#20962)

2025-11-02 14:35:33 +01:00

loops

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

narrow

[ty] Implicit type aliases: Support for PEP 604 unions (#21195)

2025-11-03 21:50:25 +01:00

regression

[ty] Fix panic due to simplifying Divergent types out of intersections types (#21253)

2025-11-03 15:41:11 +00:00

scopes

[ty] Improve error messages for unresolved attribute diagnostics (#20963)

2025-10-19 10:58:25 +01:00

shadowing

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

snapshots

[ty] don't assume in diagnostic messages that a TypedDict key error is about subscript access (#21166)

2025-10-31 10:49:59 -04:00

stubs

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

subscript

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

suppressions

[ty] Add suggestion to unknown rule diagnostics, rename unknown-rule lint to ignore-comment-unknown-rule (#20948)

2025-10-18 12:44:21 +02:00

type_compendium

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

type_of

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

type_properties

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

type_qualifiers

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

unary

Update class literal display to use <class 'Foo'> style (#17889)

2025-05-06 20:11:25 -04:00

with

[ty] Use typing.Self for the first parameter of instance methods (#20517)

2025-09-29 21:08:08 +02:00

.mdformat.toml

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

async.md

[ty] Support async/await, async with and yield from (#19595)

2025-07-30 11:51:21 +02:00

attributes.md

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

bidirectional.md

[ty] Support type context of union attribute assignments (#21170)

2025-10-31 12:41:14 -04:00

classes.md

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

cycle.md

[ty] Avoid ever-growing default types (#20991)

2025-10-21 19:13:36 +02:00

decorators.md

ty_python_semantic: add union type context to function call type errors

2025-05-09 13:40:51 -04:00

del.md

[ty] No union with Unknown for module-global symbols (#20664)

2025-10-01 16:40:30 +02:00

deprecated.md

[ty] Consistent use of American english (in rules) (#19488)

2025-07-22 16:10:38 +02:00

descriptor_protocol.md

[ty] Infer type for implicit self parameters in method bodies (#20922)

2025-10-23 09:34:39 +02:00

enums.md

[ty] Enums: allow multiple aliases to point to the same member (#20669)

2025-10-01 15:51:53 +02:00

exhaustiveness_checking.md

[ty] Improve exhaustiveness analysis for type variables with bounds or constraints (#21172)

2025-10-31 16:51:11 -04:00

final.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

implicit_type_aliases.md

[ty] Implicit type aliases: Support for PEP 604 unions (#21195)

2025-11-03 21:50:25 +01:00

instance_layout_conflict.md

[ty] initial support for slots=True in dataclasses (#20278)

2025-09-07 18:25:35 +01:00

intersection_types.md

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

invalid_syntax.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

known_constants.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

literal_promotion.md

[ty] Do not promote literals in contravariant positions of generic specializations (#21171)

2025-10-31 17:48:34 +01:00

mdtest_config.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

mdtest_custom_typeshed.md

[ty] Remove Type::Tuple (#19669)

2025-08-11 22:03:32 +01:00

metaclass.md

Update class literal display to use <class 'Foo'> style (#17889)

2025-05-06 20:11:25 -04:00

mro.md

[ty] Implicit type aliases: Support for PEP 604 unions (#21195)

2025-11-03 21:50:25 +01:00

named_tuple.md

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

overloads.md

[ty] Infer type of self for decorated methods and properties (#21123)

2025-10-29 21:22:38 +00:00

pep613_type_aliases.md

[ty] Fall back to Divergent for deeply nested specializations (#20988)

2025-10-22 14:29:10 +02:00

pep695_type_aliases.md

[ty] Add cycle handling to lazy_default (#20967)

2025-10-23 10:05:08 +02:00

properties.md

[ty] "foo".startswith is not an instance of types.MethodWrapperType (#20317)

2025-09-10 11:14:26 +00:00

protocols.md

[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

2025-10-27 11:19:12 +00:00

public_types.md

[ty] Disambiguate classes that live in different modules but have the same fully qualified names (#20756)

2025-10-08 18:27:40 +01:00

statically_known_branches.md

[ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492)

2025-09-23 14:26:55 +00:00

sys_platform.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

sys_version_info.md

Rename Red Knot (#17820)

2025-05-03 19:49:15 +02:00

t_strings.md

[ty] Add support for PEP 750 t-strings (#20085)

2025-08-25 18:49:49 +00:00

terminal_statements.md

[ty] improve lazy scope place lookup (#19321)

2025-07-25 07:11:11 +00:00

ty_extensions.md

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

typed_dict.md

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00

union_types.md

[ty] Introduce TypeRelation::Redundancy (#20602)

2025-10-03 18:35:30 +01:00

unpacking.md

[ty] Infer more precise types for collection literals (#20360)

2025-09-17 18:51:50 -04:00

unreachable.md

[ty] Use "cannot" consistently over "can not" (#21255)

2025-11-03 10:38:20 -05:00