ruff/crates/ty_python_semantic/resources/mdtest
David Peter a1edb69ea5
[ty] Enum literal types (#19328)
## Summary

Add a new `Type::EnumLiteral(…)` variant and infer this type for member
accesses on enums.

**Example**: No more `@Todo` types here:
```py
from enum import Enum

class Answer(Enum):
    YES = 1
    NO = 2

    def is_yes(self) -> bool:
        return self == Answer.YES

reveal_type(Answer.YES)  # revealed: Literal[Answer.YES]
reveal_type(Answer.YES == Answer.NO)  # revealed: Literal[False]
reveal_type(Answer.YES.is_yes())  # revealed: bool
```

## Test Plan

* Many new Markdown tests for the new type variant
* Added enum literal types to property tests, ran property tests

## Ecosystem analysis

Summary:

Lots of false positives removed. All of the new diagnostics are
either new true positives (the majority) or known problems. Click for
detailed analysis</summary>

Details:

```diff
AutoSplit (https://github.com/Toufool/AutoSplit)
+ error[call-non-callable] src/capture_method/__init__.py:137:9: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
+ error[call-non-callable] src/capture_method/__init__.py:147:9: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
+ error[call-non-callable] src/capture_method/__init__.py:148:1: Method `__getitem__` of type `bound method CaptureMethodDict.__getitem__(key: Never, /) -> type[CaptureMethodBase]` is not callable on object of type `CaptureMethodDict`
```

New true positives. That `__getitem__` method is apparently annotated
with `Never` to prevent developers from using it.


```diff
dd-trace-py (https://github.com/DataDog/dd-trace-py)
+ error[invalid-assignment] ddtrace/vendor/psutil/_common.py:29:5: Object of type `None` is not assignable to `Literal[AddressFamily.AF_INET6]`
+ error[invalid-assignment] ddtrace/vendor/psutil/_common.py:33:5: Object of type `None` is not assignable to `Literal[AddressFamily.AF_UNIX]`
```

Arguably true positives:
e0a772c28b/ddtrace/vendor/psutil/_common.py (L29)

```diff
ignite (https://github.com/pytorch/ignite)
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:190:34: Argument to bound method `__call__` is incorrect: Expected `((...) -> Unknown) | None`, found `Literal["123"]`
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:220:37: Argument to function `default_event_filter` is incorrect: Expected `Engine`, found `None`
+ error[invalid-argument-type] tests/ignite/engine/test_custom_events.py:220:43: Argument to function `default_event_filter` is incorrect: Expected `int`, found `None`
+ error[call-non-callable] tests/ignite/engine/test_custom_events.py:561:9: Object of type `CustomEvents` is not callable
+ error[invalid-argument-type] tests/ignite/metrics/test_frequency.py:50:38: Argument to bound method `attach` is incorrect: Expected `Events`, found `CallableEventWithFilter`
```

All true positives. Some of them are inside `pytest.raises(TypeError,
…)` blocks 🙃

```diff
meson (https://github.com/mesonbuild/meson)
+ error[invalid-argument-type] unittests/internaltests.py:243:51: Argument to bound method `__init__` is incorrect: Expected `bool`, found `Literal[MachineChoice.HOST]`
+ error[invalid-argument-type] unittests/internaltests.py:271:51: Argument to bound method `__init__` is incorrect: Expected `bool`, found `Literal[MachineChoice.HOST]`
```

New true positives. Enum literals can not be assigned to `bool`, even if
their value types are `0` and `1`.

```diff
poetry (https://github.com/python-poetry/poetry)
+ error[invalid-assignment] src/poetry/console/exceptions.py:101:5: Object of type `Literal[""]` is not assignable to `InitVar[str]`
```

New false positive, missing support for `InitVar`.

```diff
prefect (https://github.com/PrefectHQ/prefect)
+ error[invalid-argument-type] src/integrations/prefect-dask/tests/test_task_runners.py:193:17: Argument is incorrect: Expected `StateType`, found `Literal[StateType.COMPLETED]`
```

This is confusing. There are two definitions
([one](74d8cd93ee/src/prefect/client/schemas/objects.py (L89-L100)),
[two](https://github.com/PrefectHQ/prefect/blob/main/src/prefect/server/schemas/states.py#L40))
of the `StateType` enum. Here, we're trying to assign one to the other.
I don't think that should be allowed, so this is a true positive (?).

```diff
python-htmlgen (https://github.com/srittau/python-htmlgen)
+ error[invalid-assignment] test_htmlgen/form.py:51:9: Object of type `str` is not assignable to attribute `autocomplete` of type `Autocomplete | None`
+ error[invalid-assignment] test_htmlgen/video.py:38:9: Object of type `str` is not assignable to attribute `preload` of type `Preload | None`
```

True positives. [The stubs are
wrong](01e3b911ac/htmlgen/form.pyi (L8-L10)).
These should not contain type annotations, but rather just `OFF = ...`.

```diff
rotki (https://github.com/rotki/rotki)
+ error[invalid-argument-type] rotkehlchen/tests/unit/test_serialization.py:62:30: Argument to bound method `deserialize` is incorrect: Expected `str`, found `Literal[15]`
```

New true positive.

```diff
vision (https://github.com/pytorch/vision)
+ error[unresolved-attribute] test/test_extended_models.py:302:17: Type `type[WeightsEnum]` has no attribute `DEFAULT`
+ error[unresolved-attribute] test/test_extended_models.py:302:58: Type `type[WeightsEnum]` has no attribute `DEFAULT`
```

Also new true positives. No `DEFAULT` member exists on `WeightsEnum`.
2025-07-15 21:31:53 +02:00
..
annotations [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
assignment [ty] Homogeneous and mixed tuples (#18600) 2025-06-20 18:23:54 -04:00
binary [ty] Homogeneous and mixed tuples (#18600) 2025-06-20 18:23:54 -04:00
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 Update class literal display to use <class 'Foo'> style (#17889) 2025-05-06 20:11:25 -04:00
call [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
class Update class literal display to use <class 'Foo'> style (#17889) 2025-05-06 20:11:25 -04:00
comparison [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
comprehensions
conditional [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
dataclasses [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
declaration [ty] Format conflicting types as an enumeration (#18956) 2025-06-26 14:29:33 +02:00
diagnostics [ty] Surface matched overload diagnostic directly (#18452) 2025-06-20 08:36:49 +05:30
directives [ty] Correctly handle calls to functions marked as returning Never / NoReturn (#18333) 2025-07-04 11:52:52 -07:00
doc ty_python_semantic: add union type context to function call type errors 2025-05-09 13:40:51 -04:00
exception [ty] support del statement and deletion of except handler names (#18593) 2025-06-12 07:44:42 -07:00
expression [ty] Make tuple instantiations sound (#18987) 2025-06-27 19:37:16 +01:00
function [ty] Add diagnosis for function with no return statement but with return type annotation (#18359) 2025-05-29 23:17:18 +00:00
generics [ty] Improve protocol member type checking and relation handling (#18847) 2025-06-29 10:46:33 +00:00
ide_support [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
import [ty] add support for nonlocal statements 2025-07-11 09:44:54 -07:00
literal [ty] Understand classes that inherit from subscripted Protocol[] as generic (#17832) 2025-05-09 17:39:15 +01:00
loops
narrow [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
regression
scopes distinguish references from definitions in infer_nonlocal 2025-07-15 07:55:40 -07:00
shadowing
snapshots [ty] Sync vendored typeshed stubs (#19368) 2025-07-15 18:14:46 +00:00
stubs [ty] Do not carry the generic context of Protocol or Generic in the ClassBase enum (#17989) 2025-05-22 21:37:03 -04:00
subscript [ty] Fix false positives when subscripting an object inferred as having an Intersection type (#18920) 2025-06-24 18:39:02 +00:00
suppressions
type_compendium [ty] Make tuple instantiations sound (#18987) 2025-06-27 19:37:16 +01:00
type_of [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
type_properties [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
type_qualifiers [ty] add support for nonlocal statements 2025-07-11 09:44:54 -07:00
unary Update class literal display to use <class 'Foo'> style (#17889) 2025-05-06 20:11:25 -04:00
with [ty] Add hint if async context manager is used in non-async with statement (#18299) 2025-05-26 21:34:47 +02:00
.mdformat.toml
attributes.md [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
cycle.md [ty] Add cycle handling for unpacking targets (#18078) 2025-05-13 21:27:48 +00:00
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] support del statement and deletion of except handler names (#18593) 2025-06-12 07:44:42 -07:00
descriptor_protocol.md [ty] Fix descriptor lookups for most types that overlap with None (#19120) 2025-07-05 19:34:23 +01:00
enums.md [ty] Enum literal types (#19328) 2025-07-15 21:31:53 +02:00
final.md
instance_layout_conflict.md [ty] Improve disjointness inference for NominalInstanceTypes and SubclassOfTypes (#18864) 2025-06-24 20:27:37 +00:00
intersection_types.md [ty] eliminate is_fully_static (#18799) 2025-06-24 18:02:05 -07:00
invalid_syntax.md
known_constants.md
mdtest_config.md
mdtest_custom_typeshed.md [ty] Fix duplicate diagnostics for unresolved module when an import from statement imports multiple members (#17886) 2025-05-06 12:37:10 +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] Implement implicit inheritance from Generic[] for PEP-695 generic classes (#18283) 2025-05-26 20:40:16 +01:00
named_tuple.md [ty] Add generic inference for dataclasses (#18443) 2025-06-03 09:59:43 -07:00
overloads.md [ty] Add support for @staticmethods (#18809) 2025-06-20 10:38:17 +02:00
pep695_type_aliases.md [ty] Support typing.TypeAliasType (#18156) 2025-05-19 16:36:49 +02:00
properties.md ty_python_semantic: add union type context to function call type errors 2025-05-09 13:40:51 -04:00
protocols.md [ty] Implement equivalence for protocols with method members (#18659) 2025-07-07 12:28:32 +01:00
public_types.md [ty] Infer nonlocal types as unions of all reachable bindings (#18750) 2025-06-26 12:24:40 +02:00
statically_known_branches.md [ty] Infer nonlocal types as unions of all reachable bindings (#18750) 2025-06-26 12:24:40 +02:00
sys_platform.md
sys_version_info.md
terminal_statements.md [ty] Correctly handle calls to functions marked as returning Never / NoReturn (#18333) 2025-07-04 11:52:52 -07:00
type_api.md [ty] eliminate is_fully_static (#18799) 2025-06-24 18:02:05 -07:00
typed_dict.md [ty] Reduce false positives for TypedDict types (#19354) 2025-07-15 12:47:19 +01:00
union_types.md [ty] eliminate is_fully_static (#18799) 2025-06-24 18:02:05 -07:00
unpacking.md [ty] Support variable-length tuples in unpacking assignments (#18948) 2025-06-27 15:29:04 -04:00
unreachable.md [ty] Infer nonlocal types as unions of all reachable bindings (#18750) 2025-06-26 12:24:40 +02:00