## Summary
This PR adds type inference for key-based access on `TypedDict`s and a
new diagnostic for invalid subscript accesses:
```py
class Person(TypedDict):
name: str
age: int | None
alice = Person(name="Alice", age=25)
reveal_type(alice["name"]) # revealed: str
reveal_type(alice["age"]) # revealed: int | None
alice["naem"] # Unknown key "naem" - did you mean "name"?
```
## Test Plan
Updated Markdown tests
## Summary
This PR remaps ranges in Jupyter notebooks from simple `row:column`
indices in the concatenated source code to `cell:row:col` to match
Ruff's output. This is probably not a likely change to land upstream in
`annotate-snippets`, but I didn't see a good way around it.
The remapping logic is taken nearly verbatim from here:
cd6bf1457d/crates/ruff_linter/src/message/text.rs (L212-L222)
## Test Plan
New `full` rendering test for a notebook
I was mainly focused on Ruff, but in local tests this also works for ty:
```
error[invalid-assignment]: Object of type `Literal[1]` is not assignable to `str`
--> Untitled.ipynb:cell 1:3:1
|
1 | import math
2 |
3 | x: str = 1
| ^
|
info: rule `invalid-assignment` is enabled by default
error[invalid-assignment]: Object of type `Literal[1]` is not assignable to `str`
--> Untitled.ipynb:cell 2:3:1
|
1 | import math
2 |
3 | x: str = 1
| ^
|
info: rule `invalid-assignment` is enabled by default
```
This isn't a duplicate diagnostic, just an unimaginative example:
```py
# cell 1
import math
x: str = 1
# cell 2
import math
x: str = 1
```
Summary
--
This is the other commit I wanted to spin off from #19415, currently
stacked on #19644.
This PR suppresses blank snippets for empty ranges at the very beginning
of a file, and for empty ranges in non-existent files. Ruff includes
empty ranges for IO errors, for example.
f4e93b6335/crates/ruff_linter/src/message/text.rs (L100-L110)
The diagnostics now look like this (new snapshot test):
```
error[test-diagnostic]: main diagnostic message
--> example.py:1:1
```
Instead of [^*]
```
error[test-diagnostic]: main diagnostic message
--> example.py:1:1
|
|
```
Test Plan
--
A new `ruff_db` test showing the expected output format
[^*]: This doesn't correspond precisely to the example in the PR because
of some details of the diagnostic builder helper methods in `ruff_db`,
but you can see another example in the current version of the summary in
#19415.
Summary
--
Fixes a snapshot test failure I saw in #19653 locally and in Windows CI
by
padding the hex ID to 16 digits to match the regex in
`filter_result_id`.
78e5fe0a51/crates/ty_server/tests/e2e/pull_diagnostics.rs (L380-L384)
Test Plan
--
I applied this to the branch from #19653 locally and saw that the tests
now
pass. I couldn't reproduce this failure directly on `main` or this
branch,
though.
## Summary
This PR is a spin-off from https://github.com/astral-sh/ruff/pull/19415.
It enables replacing the severity and lint name in a ty-style
diagnostic:
```
error[unused-import]: `os` imported but unused
```
with the noqa code and optional fix availability icon for a Ruff
diagnostic:
```
F401 [*] `os` imported but unused
F821 Undefined name `a`
```
or nothing at all for a Ruff syntax error:
```
SyntaxError: Expected one or more symbol names after import
```
Ruff adds the `SyntaxError` prefix to these messages manually.
Initially (d912458), I just passed a `hide_severity` flag through a
bunch of calls to get it into `annotate-snippets`, but after looking at
it again today, I think reusing the `None` severity/level gave a nicer
result. As I note in a lengthy code comment, I think all of this code
should be temporary and reverted when Ruff gets real severities, so
hopefully it's okay if it feels a little hacky.
I think the main visible downside of this approach is that we can't
style the asterisk in the fix availabilty icon in cyan, as in Ruff's
current output. It's part of the message in this PR and any styling gets
overwritten in `annotate-snippets`.
<img width="400" height="342" alt="image"
src="https://github.com/user-attachments/assets/57542ec9-a81c-4a01-91c7-bd6d7ec99f99"
/>
Hmm, I guess reusing `Level::None` also means the `F401` isn't red
anymore. Maybe my initial approach was better after all. In any case,
the rest of the PR should be basically the same, it just depends how we
want to toggle the severity.
## Test Plan
New `ruff_db` tests. These snapshots should be compared to the two tests
just above them (`hide_severity_output` vs `output` and
`hide_severity_syntax_errors` against `syntax_errors`).
## Summary
This PR fixes a few inaccuracies in attribute access on `TypedDict`s. It
also changes the return type of `type(person)` to `type[dict[str,
object]]` if `person: Person` is an inhabitant of a `TypedDict`
`Person`. We still use `type[Person]` as the *meta type* of Person,
however (see reasoning
[here](https://github.com/astral-sh/ruff/pull/19733#discussion_r2253297926)).
## Test Plan
Updated Markdown tests.
## Summary
This PR adds a new `Type::TypedDict` variant. Before this PR, we treated
`TypedDict`-based types as dynamic Todo-types, and I originally planned
to make this change a no-op. And we do in fact still treat that new
variant similar to a dynamic type when it comes to type properties such
as assignability and subtyping. But then I somehow tricked myself into
implementing some of the things correctly, so here we are. The two main
behavioral changes are: (1) we now also detect generic `TypedDict`s,
which removes a few false positives in the ecosystem, and (2) we now
support *attribute* access (not key-based indexing!) on these types,
i.e. we infer proper types for something like
`MyTypedDict.__required_keys__`. Nothing exciting yet, but gets the
infrastructure into place.
Note that with this PR, the type of (the type) `MyTypedDict` itself is
still represented as a `Type::ClassLiteral` or `Type::GenericAlias` (in
case `MyTypedDict` is generic). Only inhabitants of `MyTypedDict`
(instances of `dict` at runtime) are represented by `Type::TypedDict`.
We may want to revisit this decision in the future, if this turns out to
be too error-prone. Right now, we need to use `.is_typed_dict(db)` in
all the right places to distinguish between actual (generic) classes and
`TypedDict`s. But so far, it seemed unnecessary to add additional `Type`
variants for these as well.
part of https://github.com/astral-sh/ty/issues/154
## Ecosystem impact
The new diagnostics on `cloud-init` look like true positives to me.
## Test Plan
Updated and new Markdown tests
## Summary
This is a follow-up to #19321.
Narrowing constraints introduced in a class scope were not applied even
when they can be applied in lazy nested scopes. This PR fixes so that
they are now applied.
Conversely, there were cases where narrowing constraints were being
applied in places where they should not, so it is also fixed.
## Test Plan
Some TODOs in `narrow/conditionals/nested.md` are now work correctly.
## Summary
This is a follow-up to #19321.
If we try to access a class variable before it is defined, the variable
is looked up in the global scope, rather than in any enclosing scopes.
Closes https://github.com/astral-sh/ty/issues/875.
## Test Plan
New tests in `narrow/conditionals/nested.md`.
## Summary
This PR enhances the `BLE001` rule to correctly detect blind exception
handling in tuple exceptions. Previously, the rule only checked single
exception types, but Python allows catching multiple exceptions using
tuples like `except (Exception, ValueError):`.
## Test Plan
It fails the following (whereas the main branch does not):
```bash
cargo run -p ruff -- check somefile.py --no-cache --select=BLE001
```
```python
# somefile.py
try:
1/0
except (ValueError, Exception) as e:
print(e)
```
```
somefile.py:3:21: BLE001 Do not catch blind exception: `Exception`
|
1 | try:
2 | 1/0
3 | except (ValueError, Exception) as e:
| ^^^^^^^^^ BLE001
4 | print(e)
|
Found 1 error.
```
## Summary
Support `as` patterns in reachability analysis:
```py
from typing import assert_never
def f(subject: str | int):
match subject:
case int() as x:
pass
case str():
pass
case _:
assert_never(subject) # would previously emit an error
```
Note that we still don't support inferring correct types for the bound
name (`x`).
Closes https://github.com/astral-sh/ty/issues/928
## Test Plan
New Markdown tests
## Summary
This PR reduces the virality of some of the `Todo` types in
`infer_tuple_type_expression`. Rather than inferring `Todo`, we instead
infer `tuple[Todo, ...]`. This reflects the fact that whatever the
contents of the slice in a `tuple[]` type expression, we would always
infer some kind of tuple type as the result of the type expression. Any
tuple type should be assignable to `tuple[Todo, ...]`, so this shouldn't
introduce any new false positives; this can be seen in the ecosystem
report.
As a result of the change, we are now able to enforce in the signature
of `Type::infer_tuple_type_expression` that it returns an
`Option<TupleType<'db>>`, which is more strongly typed and expresses
clearly the invariant that a tuple type expression should always be
inferred as a `tuple` type. To enable this, it was necessary to refactor
several `TupleType` constructors in `tuple.rs` so that they return
`Option<TupleType>` rather than `Type`; this means that callers of these
constructor functions are now free to either propagate the
`Option<TupleType<'db>>` or convert it to a `Type<'db>`.
## Test Plan
Mdtests updated.
## Summary
When splitting triple-quoted, raw strings one has to take care before attempting to make each item have single-quotes.
Fixes#19577
---------
Co-authored-by: dylwil3 <dylwil3@gmail.com>
This is subtle, and the root cause became more apparent with #19604,
since we now have many more cases of superclasses and subclasses using
different typevars. The issue is easiest to see in the following:
```py
class C[T]:
def __init__(self, t: T) -> None: ...
class D[U](C[T]):
pass
reveal_type(C(1)) # revealed: C[int]
reveal_type(D(1)) # should be: D[int]
```
When instantiating a generic class, the `__init__` method inherits the
generic context of that class. This lets our call binding machinery
infer a specialization for that context.
Prior to this PR, the instantiation of `C` worked just fine. Its
`__init__` method would inherit the `[T]` generic context, and we would
infer `{T = int}` as the specialization based on the argument
parameters.
It didn't work for `D`. The issue is that the `__init__` method was
inheriting the generic context of the class where `__init__` was defined
(here, `C` and `[T]`). At the call site, we would then infer `{T = int}`
as the specialization — but that wouldn't help us specialize `D[U]`,
since `D` does not have `T` in its generic context!
Instead, the `__init__` method should inherit the generic context of the
class that we are performing the lookup on (here, `D` and `[U]`). That
lets us correctly infer `{U = int}` as the specialization, which we can
successfully apply to `D[U]`.
(Note that `__init__` refers to `C`'s typevars in its signature, but
that's okay; our member lookup logic already applies the `T = U`
specialization when returning a member of `C` while performing a lookup
on `D`, transforming its signature from `(Self, T) -> None` to `(Self,
U) -> None`.)
Closes https://github.com/astral-sh/ty/issues/588
This PR introduces a few related changes:
- We now keep track of each time a legacy typevar is bound in a
different generic context (e.g. class, function), and internally create
a new `TypeVarInstance` for each usage. This means the rest of the code
can now assume that salsa-equivalent `TypeVarInstance`s refer to the
same typevar, even taking into account that legacy typevars can be used
more than once.
- We also go ahead and track the binding context of PEP 695 typevars.
That's _much_ easier to track since we have the binding context right
there during type inference.
- With that in place, we can now include the name of the binding context
when rendering typevars (e.g. `T@f` instead of `T`)
## Summary
Adds an initial set of tests based on the highest-priority items in
https://github.com/astral-sh/ty/issues/154. This is certainly not yet
exhaustive (required/non-required, `total`, and other things are
missing), but will be useful to measure progress on this feature.
## Test Plan
Checked intended behavior against runtime and other type checkers.
<!--
Thank you for contributing to Ruff/ty! To help us out with reviewing,
please consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title? (Please prefix
with `[ty]` for ty pull
requests.)
- Does this pull request include references to any relevant issues?
-->
## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Part of #18972
This PR makes [unnecessary-from-float
(FURB164)](https://docs.astral.sh/ruff/rules/unnecessary-from-float/#unnecessary-from-float-furb164)'s
example error out-of-the-box.
[Old example](https://play.ruff.rs/807ef72f-9671-408d-87ab-8b8bad65b33f)
```py
Decimal.from_float(4.2)
Decimal.from_float(float("inf"))
Fraction.from_float(4.2)
Fraction.from_decimal(Decimal("4.2"))
```
[New example](https://play.ruff.rs/303680d1-8a68-4b6c-a5fd-d79c56eb0f88)
```py
from decimal import Decimal
from fractions import Fraction
Decimal.from_float(4.2)
Decimal.from_float(float("inf"))
Fraction.from_float(4.2)
Fraction.from_decimal(Decimal("4.2"))
```
The "Use instead" section also had imports added, and one of the fixed
examples was slightly wrong and needed modification.
## Test Plan
<!-- How was it tested? -->
N/A, no functionality/tests affected
## Summary
Adds validation to subscript assignment expressions.
```py
class Foo: ...
class Bar:
__setattr__ = None
class Baz:
def __setitem__(self, index: str, value: int) -> None:
pass
# We now emit a diagnostic on these statements
Foo()[1] = 2
Bar()[1] = 2
Baz()[1] = 2
```
Also improves error messages on invalid `__getitem__` expressions
## Test Plan
Update mdtests and add more to `subscript/instance.md`
---------
Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
Co-authored-by: David Peter <mail@david-peter.de>
<!--
Thank you for contributing to Ruff/ty! To help us out with reviewing,
please consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title? (Please prefix
with `[ty]` for ty pull
requests.)
- Does this pull request include references to any relevant issues?
-->
## Summary
<!-- What's the purpose of the change? What does it do, and why? -->
Part of #18972
This PR makes [meta-class-abc-meta
(FURB180)](https://docs.astral.sh/ruff/rules/meta-class-abc-meta/#meta-class-abc-meta-furb180)'s
example error out-of-the-box.
[Old example](https://play.ruff.rs/6beca1be-45cd-4e5a-aafa-6a0584c10d64)
```py
class C(metaclass=ABCMeta):
pass
```
[New example](https://play.ruff.rs/bbad34da-bf07-44e6-9f34-53337e8f57d4)
```py
import abc
class C(metaclass=abc.ABCMeta):
pass
```
The "Use instead" section as also modified similarly.
## Test Plan
<!-- How was it tested? -->
N/A, no functionality/tests affected
## Summary
Fixes#18729 and fixes#16802
## Test Plan
Manually verified via CLI that Ruff no longer enters an infinite loop by
running:
```sh
echo 1 | ruff --isolated check - --select I002,UP010 --fix
```
with `required-imports = ["from __future__ import generator_stop"]` set
in the config, confirming “All checks passed!” and no snapshots were
generated.
---------
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
Summary
--
Fixes#19640. I'm not sure these are the exact fixes we really want, but
I
reproduced the issue in a 32-bit Docker container and tracked down the
causes,
so I figured I'd open a PR.
As I commented on the issue, the `goto_references` test depends on the
iteration
order of the files in an `FxHashSet` in `Indexed`. In this case, we can
just
sort the output in test code.
Similarly, the tuple case depended on the order of overloads inserted in
an
`FxHashMap`. `FxIndexMap` seemed like a convenient drop-in replacement,
but I
don't know if that will have other detrimental effects. I did have to
change the
assertion for the tuple test, but I think it should now be stable across
architectures.
Test Plan
--
Running the tests in the aforementioned Docker container
Issue: https://github.com/astral-sh/ruff/issues/19498
## Summary
[missing-required-import](https://docs.astral.sh/ruff/rules/missing-required-import/)
inserts the missing import on the line immediately following the last
line of the docstring. However, if the dosctring is immediately followed
by a continuation token (i.e. backslash) then this leads to a syntax
error because Python interprets the docstring and the inserted import to
be on the same line.
The proposed solution in this PR is to check if the first token after a
file docstring is a continuation character, and if so, to advance an
additional line before inserting the missing import.
## Test Plan
Added a unit test, and the following example was verified manually:
Given this simple test Python file:
```python
"Hello, World!"\
print(__doc__)
```
and this ruff linting configuration in the `pyproject.toml` file:
```toml
[tool.ruff.lint]
select = ["I"]
[tool.ruff.lint.isort]
required-imports = ["import sys"]
```
Without the changes in this PR, the ruff linter would try to insert the
missing import in line 2, resulting in a syntax error, and report the
following:
`error: Fix introduced a syntax error. Reverting all changes.`
With the changes in this PR, ruff correctly advances one more line
before adding the missing import, resulting in the following output:
```python
"Hello, World!"\
import sys
print(__doc__)
```
---------
Co-authored-by: Jim Hoekstra <jim.hoekstra@pacmed.nl>
## Summary
This PR improves our generics solver such that we are able to solve the
`TypeVar` in this snippet to `int | str` (the union of the elements in
the heterogeneous tuple) by upcasting the heterogeneous tuple to its
pure-homogeneous-tuple supertype:
```py
def f[T](x: tuple[T, ...]) -> T:
return x[0]
def g(x: tuple[int, str]):
reveal_type(f(x))
```
## Test Plan
Mdtests. Some TODOs remain in the mdtest regarding solving `TypeVar`s
for mixed tuples, but I think this PR on its own is a significant step
forward for our generics solver when it comes to tuple types.
---------
Co-authored-by: Douglas Creager <dcreager@dcreager.net>
## Summary
Add support for `async for` loops and async iterables.
part of https://github.com/astral-sh/ty/issues/151
## Ecosystem impact
```diff
- boostedblob/listing.py:445:54: warning[unused-ignore-comment] Unused blanket `type: ignore` directive
```
This is correct. We now find a true positive in the `# type: ignore`'d
code.
All of the other ecosystem hits are of the type
```diff
trio (https://github.com/python-trio/trio)
+ src/trio/_core/_tests/test_guest_mode.py:532:24: error[not-iterable] Object of type `MemorySendChannel[int] | MemoryReceiveChannel[int]` may not be iterable
```
The message is correct, because only `MemoryReceiveChannel` has an
`__aiter__` method, but `MemorySendChannel` does not. What's not correct
is our inferred type here. It should be `MemoryReceiveChannel[int]`, not
the union of the two. This is due to missing unpacking support for tuple
subclasses, which @AlexWaygood is working on. I don't think this should
block merging this PR, because those wrong types are already there,
without this PR.
## Test Plan
New Markdown tests and snapshot tests for diagnostics.
## Summary
I was a bit stuck on some snapshot differences I was seeing in #19415,
but @BurntSushi pointed out that `annotate-snippets` already normalizes
tabs on its own, which was very helpful! Instead of applying this change
directly to the other branch, I wanted to try applying it in
`ruff_linter` first. This should very slightly reduce the number of
changes in #19415 proper.
It looks like `annotate-snippets` always expands a tab to four spaces,
whereas I think we were aligning to tab stops:
```diff
6 | spam(ham[1], { eggs: 2})
7 | #: E201:1:6
- 8 | spam( ham[1], {eggs: 2})
- | ^^^ E201
+ 8 | spam( ham[1], {eggs: 2})
+ | ^^^^ E201
```
```diff
61 | #: E203:2:15 E702:2:16
62 | if x == 4:
-63 | print(x, y) ; x, y = y, x
- | ^ E203
+63 | print(x, y) ; x, y = y, x
+ | ^^^^ E203
```
```diff
E27.py:15:6: E271 [*] Multiple spaces after keyword
|
-13 | True and False
+13 | True and False
14 | #: E271
15 | a and b
| ^^ E271
```
I don't think this is too bad and has the major benefit of allowing us
to pass the non-tab-expanded range to `annotate-snippets` in #19415,
where it's also displayed in the header. Ruff doesn't have this problem
currently because it uses its own concise diagnostic output as the
header for full diagnostics, where the pre-expansion range is used
directly.
## Test Plan
Existing tests with a few snapshot updates
## Summary
- Add support for the return types of `async` functions
- Add type inference for `await` expressions
- Add support for `async with` / async context managers
- Add support for `yield from` expressions
This PR is generally lacking proper error handling in some cases (e.g.
illegal `__await__` attributes). I'm planning to work on this in a
follow-up.
part of https://github.com/astral-sh/ty/issues/151
closes https://github.com/astral-sh/ty/issues/736
## Ecosystem
There are a lot of true positives on `prefect` which look similar to:
```diff
prefect (https://github.com/PrefectHQ/prefect)
+ src/integrations/prefect-aws/tests/workers/test_ecs_worker.py:406:12: error[unresolved-attribute] Type `str` has no attribute `status_code`
```
This is due to a wrong return type annotation
[here](e926b8c4c1/src/integrations/prefect-aws/tests/workers/test_ecs_worker.py (L355-L391)).
```diff
mitmproxy (https://github.com/mitmproxy/mitmproxy)
+ test/mitmproxy/addons/test_clientplayback.py:18:1: error[invalid-argument-type] Argument to function `asynccontextmanager` is incorrect: Expected `(...) -> AsyncIterator[Unknown]`, found `def tcp_server(handle_conn, **server_args) -> Unknown | tuple[str, int]`
```
[This](a4d794c59a/test/mitmproxy/addons/test_clientplayback.py (L18-L19))
is a true positive. That function should return
`AsyncIterator[Address]`, not `Address`.
I looked through almost all of the other new diagnostics and they all
look like known problems or true positives.
## Typing conformance
The typing conformance diff looks good.
## Test Plan
New Markdown tests
Summary
--
This PR adds a `Checker::context` method that returns the underlying
`LintContext` to unify `Candidate::into_diagnostic` and
`Candidate::report_diagnostic` in our ambiguous Unicode character
checks. This avoids some duplication and also avoids collecting a `Vec`
of `Candidate`s only to iterate over it later.
Test Plan
--
Existing tests
## Summary
Fixes#19385.
Based on [unnecessary-placeholder
(PIE790)](https://docs.astral.sh/ruff/rules/unnecessary-placeholder/)
behavior, [ellipsis-in-non-empty-class-body
(PYI013)](https://docs.astral.sh/ruff/rules/ellipsis-in-non-empty-class-body/)
now safely preserve inline comment on ellipsis removal.
## Test Plan
A new test class was added:
```python
class NonEmptyChildWithInlineComment:
value: int
... # preserve me
```
with the following expected fix:
```python
class NonEmptyChildWithInlineComment:
value: int
# preserve me
```
The diagram is written in the Dot language, which can
be converted to SVG (or any other image) by GraphViz.
I thought it was a good idea to write this down in
preparation for adding routines that list modules.
Code reuse is likely to be difficult and I wanted to
be sure I understood how it worked.
I mostly just did this because the long string literals were annoying
me. And these can make rustfmt give up on formatting.
I also re-flowed some long comment lines while I was here.
I'm not sure if this used to be used elsewhere, but it no longer is.
And it looks like an internal-only helper function, so just un-export
it.
And note that `ModuleNameIngredient` is also un-exported, so this
function isn't really usable outside of its defining module anyway.
Summary
--
I noticed while reviewing #19390 that in `check_tokens` we were still
passing
around an extra `LinterSettings`, despite all of the same functions also
receiving a `LintContext` with its own settings.
This PR adds the `LintContext::settings` method and calls that instead
of using
the separate `LinterSettings`.
Test Plan
--
Existing tests
## Summary
Resolves#19531
I've implemented a check to determine whether the for_stmt target is
declared as global or nonlocal. I believe we should skip the rule in all
such cases, since variables declared this way are intended for use
outside the loop scope, making value changes expected behavior.
## Test Plan
Added two test cases for global and nonlocal variable to snapshot.
This PR improves the "signature help" language server feature in two
ways:
1. It adds support for the recently-introduced "stub mapper" which maps
symbol declarations within stubs to their implementation counterparts.
This allows the signature help to display docstrings from the original
implementation.
2. It incorporates a more robust fix to a bug that was addressed in a
[previous PR](https://github.com/astral-sh/ruff/pull/19542). It also
adds more comprehensive tests to cover this case.
Co-authored-by: UnboundVariable <unbound@gmail.com>
This eliminates the panic reported in
https://github.com/astral-sh/ty/issues/909, though it doesn't address
the underlying cause, which is that we aren't yet checking the types of
the fields of a protocol when checking whether a class implements the
protocol. And in particular, if a class explictly opts out of iteration
via
```py
class NotIterable:
__iter__ = None
```
we currently treat that as "having an `__iter__`" member, and therefore
implementing `Iterable`.
Note that the assumption that was in the comment before is still
correct: call binding will have already checked that the argument
satisfies `Iterable`, and so it shouldn't be an error to iterate over
said argument. But arguably, the new logic in this PR is a better way to
discharge that assumption — instead of panicking if we happen to be
wrong, fall back on an unknown iteration result.
## Summary
Fixes#18844
I'm not too sure if the solution is as simple as the way I implemented
it, but I'm curious to see if we are covering all cases correctly here.
---------
Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>
Co-authored-by: Brent Westbrook <brentrwestbrook@gmail.com>
<!--
Thank you for contributing to Ruff/ty! To help us out with reviewing,
please consider the following:
- Does this pull request include a summary of the change? (See below.)
- Does this pull request include a descriptive title? (Please prefix
with `[ty]` for ty pull
requests.)
- Does this pull request include references to any relevant issues?
-->
## Summary
As a follow-up to #18949 (suggested
[here](https://github.com/astral-sh/ruff/pull/18949#pullrequestreview-2998417889)),
this PR implements auto-fix logic for `PLC0207`.
## Test Plan
<!-- How was it tested? -->
Existing tests pass, with updates to the snapshot so that it expects the
new output that comes along with the auto-fix.
## Summary
Split the "Generator functions" tests into two parts. The first part
(synchronous) refers to a function called `i` from a function `i2`. But
`i` is later redeclared in the asynchronous part, which was probably not
intended.
As of [this cpython PR](https://github.com/python/cpython/pull/135996),
it is not allowed to concatenate t-strings with non-t-strings,
implicitly or explicitly. Expressions such as `"foo" t"{bar}"` are now
syntax errors.
This PR updates some AST nodes and parsing to reflect this change.
The structural change is that `TStringPart` is no longer needed, since,
as in the case of `BytesStringLiteral`, the only possibilities are that
we have a single `TString` or a vector of such (representing an implicit
concatenation of t-strings). This removes a level of nesting from many
AST expressions (which is what all the snapshot changes reflect), and
simplifies some logic in the implementation of visitors, for example.
The other change of note is in the parser. When we meet an implicit
concatenation of string-like literals, we now count the number of
t-string literals. If these do not exhaust the total number of
implicitly concatenated pieces, then we emit a syntax error. To recover
from this syntax error, we encode any t-string pieces as _invalid_
string literals (which means we flag them as invalid, record their
range, and record the value as `""`). Note that if at least one of the
pieces is an f-string we prefer to parse the entire string as an
f-string; otherwise we parse it as a string.
This logic is exactly the same as how we currently treat
`BytesStringLiteral` parsing and error recovery - and carries with it
the same pros and cons.
Finally, note that I have not implemented any changes in the
implementation of the formatter. As far as I can tell, none are needed.
I did change a few of the fixtures so that we are always concatenating
t-strings with t-strings.