David Peter e55bc943e5 [ty] Reachability and narrowing for enum methods (#21130) ...

## Summary

Adds proper type narrowing and reachability analysis for matching on
non-inferable type variables bound to enums. For example:

```py
from enum import Enum

class Answer(Enum):
    NO = 0
    YES = 1

    def is_yes(self) -> bool:  # no error here!
        match self:
            case Answer.YES:
                return True
            case Answer.NO:
                return False
```

closes https://github.com/astral-sh/ty/issues/1404

## Test Plan

Added regression tests

2025-10-30 15:38:57 +01:00

..

annotations

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

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

assignment

[ty] Prefer declared type for invariant collection literals (#20927)

2025-10-16 16:11:28 -04:00

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] Avoid duplicate diagnostics during multi-inference of standalone expressions (#21056)

2025-10-24 13:21:39 -04:00

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] Use range instead of custom IntIterable (#21138)

2025-10-30 15:21:55 +01:00

conditional

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

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

dataclasses

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

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

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] Delegate truthiness inference of an enum Literal type to its enum-instance supertype (#21060)

2025-10-24 14:34:16 +01:00

function

[ty] Improve disambiguation of types via fully qualified names (#20141)

2025-08-29 08:44:18 +00:00

generics

[ty] Reformat constraint set mdtests (#21111)

2025-10-28 14:59:49 -04:00

ide_support

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

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

import

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

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

literal

[ty] Treat functions, methods, and dynamic types as function-like Callables (#20842)

2025-10-13 15:21:55 +02:00

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] Reachability and narrowing for enum methods (#21130)

2025-10-30 15:38:57 +01:00

regression

[ty] Fix rare panic with highly cyclic TypeVar definitions (#21059)

2025-10-24 18:30:54 +02:00

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

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

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] Heterogeneous unpacking support for unions (#20377)

2025-10-15 19:30:03 +01:00

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] Move constraint set mdtest functions into ConstraintSet class (#21108)

2025-10-28 14:32:41 -04:00

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 range instead of custom IntIterable (#21138)

2025-10-30 15:21:55 +01:00

bidirectional.md

[ty] Use constructor parameter types as type context (#21054)

2025-10-24 20:14:18 +00:00

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] Reachability and narrowing for enum methods (#21130)

2025-10-30 15:38:57 +01:00

final.md

Rename Red Knot (#17820)

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

implicit_type_aliases.md

[ty] no more diverging query cycles in type expressions (#20359)

2025-09-16 16:44:11 -07:00

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] Expansion of enums into unions of literals (#19382)

2025-07-21 19:37:55 +02:00

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

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

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

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

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

typed_dict.md

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

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

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

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