## Summary
Get rid of the catch-all todo type from subscripting a base type we
haven't implemented handling for yet in a type expression, and turn it
into a diagnostic instead.
Handle a few more cases explicitly, to avoid false positives from the
above change:
1. Subscripting any dynamic type (not just a todo type) in a type
expression should just result in that same dynamic type. This is
important for gradual guarantee, and matches other type checkers.
2. Subscripting a generic alias may be an error or not, depending
whether the specialization itself contains typevars. Don't try to handle
this yet (it should be handled in a later PR for specializing generic
non-PEP695 type aliases), just use a dedicated todo type for it.
3. Add a temporary todo branch to avoid false positives from string PEP
613 type aliases. This can be removed in the next PR, with PEP 613 type
alias support.
## Test Plan
Adjusted mdtests, ecosystem.
All new diagnostics in conformance suite are supposed to be diagnostics,
so this PR is a strict improvement there.
New diagnostics in the ecosystem are surfacing cases where we already
don't understand an annotation, but now we emit a diagnostic about it.
They are mostly intentional choices. Analysis of particular cases:
* `attrs`, `bokeh`, `django-stubs`, `dulwich`, `ibis`, `kornia`,
`mitmproxy`, `mongo-python-driver`, `mypy`, `pandas`, `poetry`,
`prefect`, `pydantic`, `pytest`, `scrapy`, `trio`, `werkzeug`, and
`xarray` are all cases where under `from __future__ import annotations`
or Python 3.14 deferred-annotations semantics, we follow normal
name-scoping rules, whereas some other type checkers prefer global names
over local names. This means we don't like it if e.g. you have a class
with a method or attribute named `type` or `tuple`, and you also try to
use `type` or `tuple` in method/attribute annotations of that class.
This PR isn't changing those semantics, just revealing them in more
cases where previously we just silently fell back to `Unknown`. I think
failing with a diagnostic (so authors can alias names as needed to avoid
relying on scoping rules that differ between type checkers) is better
than failing silently here.
* `beartype` assumes we support `TypeForm` (because it only supports
mypy and pyright, it uses `if MYPY:` to hide the `TypeForm` from mypy,
and pyright supports `TypeForm`), and we don't yet.
* `graphql-core` likes to use a `try: ... except ImportError: ...`
pattern for importing special forms from `typing` with fallback to
`typing_extensions`, instead of using `sys.version_info` checks. We
don't handle this well when type checking under an older Python version
(where the import from `typing` is not found); we see the imported name
as of type e.g. `Unknown | SpecialFormType(...)`, and because of the
union with `Unknown` we fail to handle it as the special form type. Mypy
and pyright also don't seem to support this pattern. They don't complain
about subscripting such special forms, but they do silently fail to
treat them as the desired special form. Again here, if we are going to
fail I'd rather fail with a diagnostic rather than silently.
* `ibis` is [trying to
use](https://github.com/ibis-project/ibis/blob/main/ibis/common/collections.py#L372)
`frozendict: type[FrozenDict]` as a way to create a "type alias" to
`FrozenDict`, but this is wrong: that means `frozendict:
type[FrozenDict[Any, Any]]`.
* `mypy` has some errors due to the fact that type-checking `typing.pyi`
itself (without knowing that it's the real `typing.pyi`) doesn't work
very well.
* `mypy-protobuf` imports some types from the protobufs library that end
up unioned with `Unknown` for some reason, and so we don't allow
explicit-specialization of them. Depending on the reason they end up
unioned with `Unknown`, we might want to better support this? But it's
orthogonal to this PR -- we aren't failing any worse here, just alerting
the author that we didn't understand their annotation.
* `pwndbg` has unresolved references due to star-importing from a
dependency that isn't installed, and uses un-imported names like `Dict`
in annotation expressions. Some of the unresolved references were hidden
by
https://github.com/astral-sh/ruff/blob/main/crates/ty_python_semantic/src/types/infer/builder.rs#L7223-L7228
when some annotations previously resolved to a Todo type that no longer
do.
## Summary
Add support for `Literal` types in implicit type aliases.
part of https://github.com/astral-sh/ty/issues/221
## Ecosystem analysis
This looks good to me, true positives and known problems.
## Test Plan
New Markdown tests.
Fixes https://github.com/astral-sh/ty/issues/1368
## Summary
Add support for patterns like this, where a type alias to a literal type
(or union of literal types) is used to subscript `typing.Literal`:
```py
type MyAlias = Literal[1]
def _(x: Literal[MyAlias]): ...
```
This shows up in the ecosystem report for PEP 613 type alias support.
One interesting case is an alias to `bool` or an enum type. `bool` is an
equivalent type to `Literal[True, False]`, which is a union of literal
types. Similarly an enum type `E` is also equivalent to a union of its
member literal types. Since (for explicit type aliases) we infer the RHS
directly as a type expression, this makes it difficult for us to
distinguish between `bool` and `Literal[True, False]`, so we allow
either one to (or an alias to either one) to appear inside `Literal`,
where other type checkers allow only the latter.
I think for implicit type aliases it may be simpler to support only
types derived from actually subscripting `typing.Literal`, though, so I
didn't make a TODO-comment commitment here.
## Test Plan
Added mdtests, including TODO-filled tests for PEP 613 and implicit type
aliases.
### Conformance suite
All changes here are positive -- we now emit errors on lines that should
be errors. This is a side effect of the new implementation, not the
primary purpose of this PR, but it's still a positive change.
### Ecosystem
Eliminates one ecosystem false positive, where a PEP 695 type alias for
a union of literal types is used to subscript `typing.Literal`.
## Summary
Fixes pull-types panics for illegal annotations like
`Literal[object[index]]`.
Originally reported by @AlexWaygood
## Test Plan
* Verified that this caused panics in the playground, when typing (and
potentially hovering over) `x: Literal[obj[0]]`.
* Added a regression test
## 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`.
Carl Meyer
David Peter
David Peter
Micha Reiser