Re: #17526
## Summary
Add integration test for semantic syntax for `IrrefutableCasePattern`,
`SingleStarredAssignment`, `WriteToDebug`, and `InvalidExpression`.
## Notes
- Following @ntBre's suggestion, I will keep the test coming in batches
like this over the next few days in separate PRs to keep the review load
per PR manageable while also not spamming too many.
- I did not add a test for `del __debug__` which is one of the examples
in `crates/ruff_python_parser/src/semantic_errors.rs:1051`.
For python version `<= 3.8` there is no error and for `>=3.9` the error
is not `WriteToDebug` but `SyntaxError: cannot delete __debug__ on
Python 3.9 (syntax was removed in 3.9)`.
- The `blacken-docs` bypass is necessary because otherwise the test does
not pass pre-commit checks; but we want to check for this faulty syntax.
<!-- What's the purpose of the change? What does it do, and why? -->
## Test Plan
This is a test.
Summary
--
This was suggested on Discord, I hope this is roughly what we had in
mind. I took the message from the ty README, but I'm more than happy to
update it. Otherwise I just tried to mimic the appearance of the `ruff
analyze graph` warning (although I'm realizing now the whole text is
bold for ruff).
Test Plan
--
New warnings in the CLI tests. I thought this might be undesirable but
it looks like uv did the same thing
(https://github.com/astral-sh/uv/pull/6166).

This makes one very simple change: we report all call binding
errors from each union variant.
This does result in duplicate-seeming diagnostics. For example,
when two union variants are invalid for the same reason.
## Summary
Adds a simple progress bar for the `ty check` CLI command. The style is
taken from uv, and like uv the bar is always shown - for smaller
projects it is fast enough that it isn't noticeable. We could
alternatively hide it completely based on some heuristic for the number
of files, or only show it after some amount of time.
I also disabled it when `--watch` is passed, cancelling inflight checks
was leading to zombie progress bars. I think we can fix this by using
[`MultiProgress`](https://docs.rs/indicatif/latest/indicatif/struct.MultiProgress.html)
and managing all the bars globally, but I left that out for now.
Resolves https://github.com/astral-sh/ty/issues/98.
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## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
* `airflow.models.Connection` → `airflow.sdk.Connection`
* `airflow.models.Variable` → `airflow.sdk.Variable`
## Test Plan
<!-- How was it tested? -->
The test fixtures has been updated (see the first commit for easier
review)
This does a deeper removal of the `lint:` prefix by removing the
`DiagnosticId::as_str` method and replacing it with `as_concise_str`. We
remove the associated error type and simplify the `Display` impl for
`DiagnosticId` as well.
This turned out to catch a `lint:` that was still in the diagnostic
output: the part that says why a lint is enabled.
We just set the ID on the `Message` and it just does what we want in
this case. I think I didn't do this originally because I was trying to
preserve the existing rendering? I'm not sure. I might have just missed
this method.
In a subsequent commit, we're going to start using `annotate-snippets`'s
functionality for diagnostic IDs in the rendering. As part of doing
that, I wanted to remove this special casing of an empty message. I did
that independently to see what, if anything, would change. (The changes
look fine to me. They'll be tweaked again in the next commit along with
a bunch of others.)
## Summary
Use a self-reference "marker" ~~and fixpoint iteration~~ to solve the
stack overflow problems with recursive protocols. This is not pretty and
somewhat tedious, but seems to work fine. Much better than all my
fixpoint-iteration attempts anyway.
closes https://github.com/astral-sh/ty/issues/93
## Test Plan
New Markdown tests.
## Summary
Add cycle handling for `try_metaclass` and `pep695_generic_context`
queries, as well as adjusting the cycle handling for `try_mro` to ensure
that it short-circuits on cycles and won't grow MROs indefinitely.
This reduces the number of failing fuzzer seeds from 68 to 17. The
latter count includes fuzzer seeds 120, 160, and 335, all of which
previously panicked but now either hang or are very slow; I've
temporarily skipped those seeds in the fuzzer until I can dig into that
slowness further.
This also allows us to move some more ecosystem projects from `bad.txt`
to `good.txt`, which I've done in
https://github.com/astral-sh/ruff/pull/17903
## Test Plan
Added mdtests.
@AlexWaygood pointed out that the `SliceLiteral` type variant was
originally created to handle slices before we had generics.
https://github.com/astral-sh/ruff/pull/17927#discussion_r2078115787
Now that we _do_ have generics, we can use a specialization of the
`slice` builtin type for slice literals.
This depends on https://github.com/astral-sh/ruff/pull/17956, since we
need to make sure that all typevar defaults are fully substituted when
specializing `slice`.
It's possible for a typevar to list another typevar as its default
value:
```py
class C[T, U = T]: ...
```
When specializing this class, if a type isn't provided for `U`, we would
previously use the default as-is, leaving an unspecialized `T` typevar
in the specialization. Instead, we want to use what `T` is mapped to as
the type of `U`.
```py
reveal_type(C()) # revealed: C[Unknown, Unknown]
reveal_type(C[int]()) # revealed: C[int, int]
reveal_type(C[int, str]()) # revealed: C[int, str]
```
This is especially important for the `slice` built-in type.
## Summary
This PR is a first step toward integration of the new `Diagnostic` type
into ruff. There are two main changes:
- A new `UnifiedFile` enum wrapping `File` for red-knot and a
`SourceFile` for ruff
- ruff's `Message::SyntaxError` variant is now a `Diagnostic` instead of
a `SyntaxErrorMessage`
The second of these changes was mostly just a proof of concept for the
first, and it went pretty smoothly. Converting `DiagnosticMessage`s will
be most of the work in replacing `Message` entirely.
## Test Plan
Existing tests, which show no changes.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Micha Reiser <micha@reiser.io>
Summary
--
This PR resolves both the typing-related and syntax error TODOs added in
#17563 by tracking a set of `global` bindings for each scope. As
discussed below, we avoid the additional AST traversal from ruff by
collecting `Name`s from `global` statements while building the semantic
index and emit a syntax error if the `Name` is already bound in the
current scope at the point of the `global` statement. This has the
downside of separating the error from the `SemanticSyntaxChecker`, but I
plan to explore using this approach in the `SemanticSyntaxChecker`
itself as a follow-up. It seems like this may be a better approach for
ruff as well.
Test Plan
--
Updated all of the related mdtests to remove the TODOs (and add quotes I
forgot on the messages).
There is one remaining TODO, but it requires `nonlocal` support, which
isn't even incorporated into the `SemanticSyntaxChecker` yet.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Fixes: astral-sh/ty#159
This PR adds support for using `Self` in methods.
When the type of an annotation is `TypingSelf` it is converted to a type
var based on:
https://typing.python.org/en/latest/spec/generics.html#self
I just skipped Protocols because it had more problems and the tests was
not useful.
Also I need to create a follow up PR that implicitly assumes `self`
argument has type `Self`.
In order to infer the type in the `in_type_expression` method I needed
to have scope id and semantic index available. I used the idea from
[this PR](https://github.com/astral-sh/ruff/pull/17589/files) to pass
additional context to this method.
Also I think in all places that `in_type_expression` is called we need
to have this context because `Self` can be there so I didn't split the
method into one version with context and one without.
## Test Plan
Added new tests from spec.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: Carl Meyer <carl@astral.sh>
#17897 added variance handling for legacy typevars — but they were only
being considered when checking generic aliases of the same class:
```py
class A: ...
class B(A): ...
class C[T]: ...
static_assert(is_subtype_of(C[B], C[A]))
```
and not for generic subclasses:
```py
class D[U](C[U]): ...
static_assert(is_subtype_of(D[B], C[A]))
```
Now we check those too!
Closes https://github.com/astral-sh/ty/issues/101
Fixes#17867
## Summary
The CPython parser does not allow generator expressions which are the
sole arguments in an argument list to have a trailing comma.
With this change, we start flagging such instances.
## Test Plan
Added new inline tests.