## Summary
This should address a problem that came up while working on
https://github.com/astral-sh/ruff/pull/18280. When looking up an
attribute (typically a dunder method) with the `MRO_NO_OBJECT_FALLBACK`
policy, the attribute is first looked up on the meta type. If the meta
type happens to be `type`, we go through the following branch in
`find_name_in_mro_with_policy`:
97ff015c88/crates/ty_python_semantic/src/types.rs (L2565-L2573)
The problem is that we now look up the attribute on `object` *directly*
(instead of just having `object` in the MRO). In this case,
`MRO_NO_OBJECT_FALLBACK` has no effect in `class_member_from_mro`:
c3feb8ce27/crates/ty_python_semantic/src/types/class.rs (L1081-L1082)
So instead, we need to explicitly respect the `MRO_NO_OBJECT_FALLBACK`
policy here by returning `Symbol::Unbound`.
## Test Plan
Added new Markdown tests that explain the ecosystem changes that we
observe.
## Summary
Fix a bug that involved writes to attributes on union/intersection types
that included modules as elements.
This is a prerequisite to avoid some ecosystem false positives in
https://github.com/astral-sh/ruff/pull/18312
## Test Plan
Added regression test
## Summary
This PR moves the diagnostics API for the language server out from the
request handler module to the diagnostics API module.
This is in preparation to add support for publishing diagnostics.
## Summary
Resolves https://github.com/astral-sh/ty/issues/485.
`infer_binary_intersection_type_comparison()` now checks for all
positive members before concluding that an operation is unsupported for
a given intersection type.
## Test Plan
Markdown tests.
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
This is a practice I followed on previous projects. Should hopefully
further help developers who want to update the documentation.
The big downside is that it's annoying to see this *as a user of the
documentation* if you don't open the Markdown file in the browser. But
I'd argue that those files don't really follow the original Markdown
spirit anyway with all the inline HTML.
## Summary
This is something I wrote a few months ago, and continued to update from
time to time. It was mostly written for my own education. I found a few
bugs while writing it at the time (there are still one or two TODOs in
the test assertions that are probably bugs). Our other tests are fairly
comprehensive, but they are usually structured around a certain
functionality or operation (subtyping, assignability, narrowing). The
idea here was to focus on individual *types and their properties*.
closes#197 (added `JustFloat` and `JustComplex` to `ty_extensions`).
## Summary
Fix remaining `knot.toml` reference and replace it with `ty.toml`. This
change was probably still in flight while we renamed things.
## Test Plan
Added a second assertion which ensures that the config file has any
effect.
## Summary
It doesn't seem to be necessary for our generics implementation to carry
the `GenericContext` in the `ClassBase` variants. Removing it simplifies
the code, fixes many TODOs about `Generic` or `Protocol` appearing
multiple times in MROs when each should only appear at most once, and
allows us to more accurately detect runtime errors that occur due to
`Generic` or `Protocol` appearing multiple times in a class's bases.
In order to remove the `GenericContext` from the `ClassBase` variant, it
turns out to be necessary to emulate
`typing._GenericAlias.__mro_entries__`, or we end up with a large number
of false-positive `inconsistent-mro` errors. This PR therefore also does
that.
Lastly, this PR fixes the inferred MROs of PEP-695 generic classes,
which implicitly inherit from `Generic` even if they have no explicit
bases.
## Test Plan
mdtests
## Summary
Fix some issues with subtying/assignability for instances vs callables.
We need to look up dunders on the class, not the instance, and we should
limit our logic here to delegating to the type of `__call__`, so it
doesn't get out of sync with the calls we allow.
Also, we were just entirely missing assignability handling for
`__call__` implemented as anything other than a normal bound method
(though we had it for subtyping.)
A first step towards considering what else we want to change in
https://github.com/astral-sh/ty/issues/491
## Test Plan
mdtests
---------
Co-authored-by: med <medioqrity@gmail.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Division works differently in Python than in Rust. If the result is
negative and there is a remainder, the division rounds down (instead of
towards zero). The remainder needs to be adjusted to compensate so that
`(lhs // rhs) * rhs + (lhs % rhs) == lhs`.
Fixesastral-sh/ty#481.
## Summary
https://github.com/astral-sh/ty/issues/111
This PR adds support for `frozen` dataclasses. It will emit a diagnostic
with a similar message to mypy
Note: This does not include emitting a diagnostic if `__setattr__` or
`__delattr__` are defined on the object as per the
[spec](https://docs.python.org/3/library/dataclasses.html#module-contents)
## Test Plan
mdtest
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Make sure that the following definitions all lead to the same outcome
(bug originally noticed by @AlexWaygood)
```py
from typing import ClassVar
class Descriptor:
def __get__(self, instance, owner) -> int:
return 42
class C:
a: ClassVar[Descriptor]
b: Descriptor = Descriptor()
c: ClassVar[Descriptor] = Descriptor()
reveal_type(C().a) # revealed: int (previously: int | Descriptor)
reveal_type(C().b) # revealed: int
reveal_type(C().c) # revealed: int
```
## Test Plan
New Markdown tests
## Summary
I think `division-by-zero` is a low-value diagnostic in general; most
real division-by-zero errors (especially those that are less obvious to
the human eye) will occur on values typed as `int`, in which case we
don't issue the diagnostic anyway. Mypy and pyright do not emit this
diagnostic.
Currently the diagnostic is prone to false positives because a) we do
not silence it in unreachable code, and b) we do not implement narrowing
of literals from inequality checks. We will probably fix (a) regardless,
but (b) is low priority apart from division-by-zero.
I think we have many more important things to do and should not allow
false positives on a low-value diagnostic to be a distraction. Not
opposed to re-enabling this diagnostic in future when we can prioritize
reducing its false positives.
References https://github.com/astral-sh/ty/issues/443
## Test Plan
Existing tests.
## Summary
This PR updates the language server to avoid panicking when there are
multiple workspace folders passed during initialization. The server
currently picks up the first workspace folder and provides a warning and
a log message.
## Test Plan
<img width="1724" alt="Screenshot 2025-05-17 at 11 43 09"
src="https://github.com/user-attachments/assets/1a7ddbc3-198d-4191-a28f-9b69321e8f99"
/>
## Summary
Resolves [#461](https://github.com/astral-sh/ty/issues/461).
ty was hardcoded to infer `BytesLiteral` types for integer indexing into
`BytesLiteral`. It will now infer `IntLiteral` types instead.
## Test Plan
Markdown tests.
Summary
--
I thought that emitting multiple diagnostics at once would be difficult
to port to a diagnostic construction model closer to ty's
`InferContext::report_lint`, so as a first step toward that, this PR
removes `Checker::report_diagnostics`.
In many cases I was able to do some related refactoring to avoid
allocating a `Vec<Diagnostic>` at all, often by adding a `Checker` field
to a `Visitor` or by passing a `Checker` instead of a `&mut
Vec<Diagnostic>`.
In other cases, I had to fall back on something like
```rust
for diagnostic in diagnostics {
checker.report_diagnostic(diagnostic);
}
```
which I guess is a bit worse than the `extend` call in
`report_diagnostics`, but hopefully it won't make too much of a
difference.
I'm still not quite sure what to do with the remaining loop cases. The
two main use cases for collecting a sequence of diagnostics before
emitting any of them are:
1. Applying a single `Fix` to a group of diagnostics
2. Avoiding an earlier diagnostic if something goes wrong later
I was hoping we could get away with just a `DiagnosticGuard` that
reported a `Diagnostic` on drop, but I guess we will still need a
`DiagnosticGuardBuilder` that can be collected in these cases and
produce a `DiagnosticGuard` once we know we actually want the
diagnostics.
Test Plan
--
Existing tests
Closes https://github.com/astral-sh/ty/issues/453.
## Summary
Add an additional info diagnostic to `unresolved-import` check to hint
to users that they should make sure their Python environment is properly
configured for ty, linking them to the corresponding doc. This
diagnostic is only shown when an import is not relative, e.g., `import
maturin` not `import .maturin`.
## Test Plan
Updated snapshots with new info message and reran tests.
The PR add the `fix safety` section for rule `SIM110` (#15584 )
### Unsafe Fix Example
```python
def predicate(item):
global called
called += 1
if called == 1:
# after first call we change the method
def new_predicate(_): return False
globals()['predicate'] = new_predicate
return True
def foo():
for item in range(10):
if predicate(item):
return True
return False
def foo_gen():
return any(predicate(item) for item in range(10))
called = 0
print(foo()) # true – returns immediately on first call
called = 0
print(foo_gen()) # false – second call uses new `predicate`
```
### Note
I notice that
[here](46be305ad2/crates/ruff_linter/src/rules/flake8_simplify/rules/reimplemented_builtin.rs (L60))
we have two rules, `SIM110` & `SIM111`. The second one seems not anymore
active. Should I delete `SIM111`?
This implements the stopgap approach described in
https://github.com/astral-sh/ty/issues/336#issuecomment-2880532213 for
handling literal types in generic class specializations.
With this approach, we will promote any literal to its instance type,
but _only_ when inferring a generic class specialization from a
constructor call:
```py
class C[T]:
def __init__(self, x: T) -> None: ...
reveal_type(C("string")) # revealed: C[str]
```
If you specialize the class explicitly, we still use whatever type you
provide, even if it's a literal:
```py
from typing import Literal
reveal_type(C[Literal[5]](5)) # revealed: C[Literal[5]]
```
And this doesn't apply at all to generic functions:
```py
def f[T](x: T) -> T:
return x
reveal_type(f(5)) # revealed: Literal[5]
```
---
As part of making this happen, we also generalize the `TypeMapping`
machinery. This provides a way to apply a function to type, returning a
new type. Complicating matters is that for function literals, we have to
apply the mapping lazily, since the function's signature is not created
until (and if) someone calls its `signature` method. That means we have
to stash away the mappings that we want to apply to the signatures
parameter/return annotations once we do create it. This requires some
minor `Cow` shenanigans to continue working for partial specializations.
This is a follow-on to #18155. For the example raised in
https://github.com/astral-sh/ty/issues/370:
```py
import tempfile
with tempfile.TemporaryDirectory() as tmp: ...
```
the new logic would notice that both overloads of `TemporaryDirectory`
match, and combine their specializations, resulting in an inferred type
of `str | bytes`.
This PR updates the logic to match our other handling of other calls,
where we only keep the _first_ matching overload. The result for this
example then becomes `str`, matching the runtime behavior. (We still do
not implement the full [overload resolution
algorithm](https://typing.python.org/en/latest/spec/overload.html#overload-call-evaluation)
from the spec.)
## Summary
Add a new diagnostic hint if you try to use PEP 604 `X | Y` union syntax
in a non-type-expression before 3.10.
closes https://github.com/astral-sh/ty/issues/437
## Test Plan
New snapshot test
