Commit Graph

856 Commits

Author SHA1 Message Date
Brent Westbrook e4f5fe8cf7
[syntax-errors] Duplicate type parameter names (#16858)
Summary
--

Detects duplicate type parameter names in function definitions, class
definitions, and type alias statements.

I also boxed the `type_params` field on `StmtTypeAlias` to make it
easier to
`match` with functions and classes. (That's the reason for the red-knot
code
owner review requests, sorry!)

Test Plan
--

New `ruff_python_syntax_errors` unit tests.

Fixes #11119.
2025-03-21 15:06:22 -04:00
Alex Waygood d21d639ee0
[red-knot] Avoid false-positive diagnostics on `*` import statements (#16899)
## Summary

This PR removes false-positive diagnostics for `*` imports. Currently we
always emit a diagnostic for these statements unless the module we're
importing from has a symbol named `"*"` in its symbol table for the
global scope. (And if we were doing everything correctly, no module ever
would have a symbol named `"*"` in its global scope!)

The fix here is sort-of hacky and won't be what we'll want to do
long-term. However, I think it's useful to do this as a first step
since:
- It significantly reduces false positives when running on code that
uses `*` imports
- It "resets" the tests to a cleaner state with many fewer TODOs, making
it easier to see what the hard work is that's still to be done.

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-03-21 14:41:49 +00:00
Alex Waygood 14eb4cac88
[red-knot] Add failing tests for `*` imports (#16873)
## Summary

This PR adds a suite of tests for wildcard (`*`) imports. The tests
nearly all fail for now, and those that don't, ahem, pass for the wrong
reasons...

I've tried to add TODO comments in all instances for places where we are
currently inferring the incorrect thing, incorrectly emitting a
diagnostic, or emitting a diagnostic with a bad error message.

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-03-21 14:17:15 +00:00
Douglas Creager c03c28d199
[red-knot] Break up call binding into two phases (#16546)
This breaks up call binding into two phases:

- **_Matching parameters_** just looks at the names and kinds
(positional/keyword) of each formal and actual parameters, and matches
them up. Most of the current call binding errors happen during this
phase.

- Once we have matched up formal and actual parameters, we can **_infer
types_** of each actual parameter, and **_check_** that each one is
assignable to the corresponding formal parameter type.

As part of this, we add information to each formal parameter about
whether it is a type form or not. Once [PEP
747](https://peps.python.org/pep-0747/) is finalized, we can hook that
up to this internal type form representation. This replaces the
`ParameterExpectations` type, which did the same thing in a more ad hoc
way.

While we're here, we add a new fluent API for building `Parameter`s,
which makes our signature constructors a bit nicer to read. We also
eliminate a TODO where we were consuming types from the argument list
instead of the bound parameter list when evaluating our special-case
known functions.

Closes #15460

---------

Co-authored-by: Micha Reiser <micha@reiser.io>
2025-03-21 09:38:11 -04:00
Dhruv Manilawala 04a8756379
[red-knot] Check subtype relation between callable types (#16804)
## Summary

Part of #15382

This PR adds support for checking the subtype relationship between the
two callable types.

The main source of reference used for implementation is
https://typing.python.org/en/latest/spec/callables.html#assignability-rules-for-callables.

The implementation is split into two phases:
1. Check all the positional parameters which includes positional-only,
standard (positional or keyword) and variadic kind
2. Collect all the keywords in a `HashMap` to do the keyword parameters
check via name lookup

For (1), there's a helper struct which is similar to `.zip_longest`
(from `itertools`) except that it allows control over one of the
iterator as that's required when processing a variadic parameter. This
is required because positional parameters needs to be checked as per
their position between the two callable types. The struct also keeps
track of the current iteration element because when the loop is exited
(to move on to the phase 2) the current iteration element would be
carried over to the phase 2 check.

This struct is internal to the `is_subtype_of` method as I don't think
it makes sense to expose it outside. It also allows me to use "self" and
"other" suffixed field names as that's only relevant in that context.

## Test Plan

Add extensive tests in markdown.

Converted all of the code snippets from
https://typing.python.org/en/latest/spec/callables.html#assignability-rules-for-callables
to use `knot_extensions.is_subtype_of` and verified the result.
2025-03-21 03:27:22 +00:00
Dhruv Manilawala 193c38199e
[red-knot] Check whether two callable types are equivalent (#16698)
## Summary

This PR checks whether two callable types are equivalent or not.

This is required because for an equivalence relationship, the default
value does not necessarily need to be the same but if the parameter in
one of the callable has a default value then the corresponding parameter
in the other callable should also have a default value. This is the main
reason a manual implementation is required.

And, as per https://typing.python.org/en/latest/spec/callables.html#id4,
the default _type_ doesn't participate in a subtype relationship, only
the optionality (required or not) participates. This means that the
following two callable types are equivalent:

```py
def f1(a: int = 1) -> None: ...
def f2(a: int = 2) -> None: ...
```

Additionally, the name of positional-only, variadic and keyword-variadic
are not required to be the same for an equivalence relation.

A potential solution to avoid the manual implementation would be to only
store whether a parameter has a default value or not but the type is
currently required to check for assignability.

## Test plan

Add tests for callable types in `is_equivalent_to.md`
2025-03-21 03:19:07 +00:00
Matthew Mckee 63e78b41cd
[red-knot] Ban most `Type::Instance` types in type expressions (#16872)
## Summary

Catch some Instances, but raise type error for the rest of them
Fixes #16851 

## Test Plan

Extend invalid.md in annotations

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-03-20 15:19:56 -07:00
Alex Waygood 296d67a496
Special-case value-expression inference of special form subscriptions (#16877)
## Summary

Currently for something like `X = typing.Tuple[str, str]`, we infer the
value of `X` as `object`. That's because `Tuple` (like many of the
symbols in the typing module) is annotated as a `_SpecialForm` instance
in typeshed's stubs:


23382f5f8c/crates/red_knot_vendored/vendor/typeshed/stdlib/typing.pyi (L215)

and we don't understand implicit type aliases yet, and the stub for
`_SpecialForm.__getitem__` says it always returns `object`:


23382f5f8c/crates/red_knot_vendored/vendor/typeshed/stdlib/typing.pyi (L198-L200)

We have existing false positives in our test suite due to this:


23382f5f8c/crates/red_knot_python_semantic/resources/mdtest/annotations/annotated.md?plain=1#L76-L78

and it's causing _many_ new false positives in #16872, which tries to
make our annotation-expression parsing stricter in some ways.

This PR therefore adds some small special casing for `KnownInstanceType`
variants that fallback to `_SpecialForm`, so that these false positives
can be avoided.

## Test Plan

Existing mdtest altered.

Cc. @MatthewMckee4
2025-03-20 21:46:02 +00:00
Shunsuke Shibayama 23382f5f8c
[red-knot] add test cases result in false positive errors (#16856)
## Summary

From #16641

The previous PR attempted to fix the errors presented in this PR, but as
discussed in the conversation, it was concluded that the approach was
undesirable and that further work would be needed to fix the errors with
a correct general solution.

In this PR, I instead add the test cases from the previous PR as TODOs,
as a starting point for future work.

## Test Plan

---------

Co-authored-by: Carl Meyer <carl@oddbird.net>
2025-03-20 17:17:54 +00:00
Matthew Mckee cdafd8e32b
Allow discovery of venv in VIRTUAL_ENV env variable (#16853)
## Summary

Fixes #16744 

Allows the cli to find a virtual environment from the VIRTUAL_ENV
environment variable if no `--python` is set

## Test Plan

Manual testing, of:
- Virtual environments explicitly activated using `source .venv/bin/activate`
- Virtual environments implicilty activated via `uv run`
- Broken virtual environments with no `pyvenv.cfg` file
2025-03-20 13:55:35 +00:00
Matthew Mckee 4ed93b4311
Show more precise messages in invalid type expressions (#16850)
## Summary

Some error messages were not very specific; this PR improves them

## Test Plan

New mdtests added; existing mdtests tweaked
2025-03-19 17:00:30 +00:00
Alex Waygood a3f3d734a1
[red-knot] Ban list literals in most contexts in type expressions (#16847)
## Summary

This PR reworks `TypeInferenceBuilder::infer_type_expression()` so that
we emit diagnostics when encountering a list literal in a type
expression. The only place where a list literal is allowed in a type
expression is if it appears as the first argument to `Callable[]`, and
`Callable` is already heavily special-cased in our type-expression
parsing.

In order to ensure that list literals are _always_ allowed as the
_first_ argument to `Callabler` (but never allowed as the second, third,
etc. argument), I had to do some refactoring of our type-expression
parsing for `Callable` annotations.

## Test Plan

New mdtests added, and existing ones updated
2025-03-19 14:42:42 +00:00
Matthew Mckee 3a5f1d46c0
[red-knot] Make' Type::in_type_expression()' exhaustive for Type::KnownInstance (#16836)
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## Summary

fixes #15048 
We want to handle more types from Type::KnownInstance 

## Test Plan

Add tests for each type added explicitly in the match

---------

Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
2025-03-19 07:36:28 -07:00
Alex Waygood f3f3e55d97
[red-knot] Minor cleanup to `infer_parameterized_known_instance_type_expression` (#16846)
## Summary

These are just cosmetic changes, but I'm separating them out into a
standalone PR to make a branch I have stacked on top of this easier to
review

## Test Plan

Existing tests all pass
2025-03-19 14:19:13 +00:00
Dhruv Manilawala a69f6240cc
[red-knot] Infer `lambda` return type as `Unknown` (#16695)
## Summary

Part of #15382

This PR infers the return type `lambda` expression as `Unknown`. In the
future, it would be more useful to infer the expression type considering
the surrounding context (#16696).

## Test Plan

Update existing test cases from `@todo` to the (verified) return type.
2025-03-18 22:48:10 +05:30
Dhruv Manilawala c3d429ddd8
[red-knot] Move `name` field on parameter kind (#16830)
## Summary

Previously, the `name` field was on `Parameter` which required it to be
always optional regardless of the parameter kind because a
`typing.Callable` signature does not have name for the parameters. This
is the case for positional-only parameters. This wasn't enforced at the
type level which meant that downstream usages would have to unwrap on
`name` even though it's guaranteed to be present.

This commit moves the `name` field from `Parameter` to the
`ParameterKind` variants and makes it optional only for
`ParameterKind::PositionalOnly` variant while required for all other
variants.

One change that's now required is that a `Callable` form using a gradual
form for parameter types (`...`) would have a default `args` and
`kwargs` name used for variadic and keyword-variadic parameter kind
respectively. This is also the case for invalid `Callable` type forms. I
think this is fine as names are not relevant in this context but happy
to make it optional even in variadic variants.

## Test Plan

No new tests; make sure existing tests are passing.
2025-03-18 22:47:44 +05:30
Matthew Mckee ab3ec4de6a
[red-knot] Emit errors for more AST nodes that are invalid (or only valid in specific contexts) in type expressions (#16822)
## Summary

Add error messages for invalid nodes in type expressions

Fixes #16816 

## Test Plan

Extend annotations/invalid.md to handle these invalid AST nodes error
messages
2025-03-18 17:16:50 +00:00
cake-monotone 4ab529803f
[red-knot] Refactor `property_tests.rs` into `property_tests` module structure (#16827)
## Summary

For now, `property_tests.rs` has grown larger and larger, making the
file difficult to read and maintain.

Although the code has been split, the test paths and full names remain
unchanged. There are no changes affecting test execution.
2025-03-18 12:59:14 +00:00
Alex Waygood 23b7df9b29
[red-knot] Simplify `IterationError` and `ContextManagerError` (#16820)
## Summary

This PR simplifies `IterationError` and `ContextManagerError` so that
they no longer "remember" what type it was that was (respectively) not
iterable or not valid as a context manager. Instead, the type that was
iterated over (or was used as a context manager) is passed back in when
calling the error struct's `report_diagnostic` method.

The motivations for this are:
- It significantly simplifies the code
- It reduces the size of these types on the stack

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-03-18 11:30:41 +00:00
cake-monotone 3e2cf5d7c4
[red-knot] Improve property test performance by cloning db instead of holding `MutexGuard` (#16823)
## Summary

This PR brings an optimization.

- `get_cached_db` no longer returns a `MutexGuard`; instead, it returns
a cloned database.

### `get_cached_db`

Previously, the `MutexGuard` was held inside the property test function
(defined in the macro), which prevented multiple property tests from
running in parallel. More specifically, the program could only test one
random test case at a time, which likely caused a significant
bottleneck.

On my local machine, running:

```
QUICKCHECK_TESTS=100000 cargo test --release -p red_knot_python_semantic -- --ignored stable
```

showed about **a 75% speedup** (from \~60s to \~15s).
2025-03-18 09:09:57 +01:00
Andrew Gallant bd9eab059f red_knot: update diagnostic output snapshots
These should all be minor cosmetic changes. To summarize:

* In many cases, `-` was replaced with `^` for primary annotations.
This is because, previously, whether `-` or `^` was used depended
on the severity. But in the new data model, it's based on whether
the annotation is "primary" or not. We could of course change this
in whatever way we want, but I think we should roll with this for now.

* The "secondary messages" in the old API are rendered as
sub-diagnostics. This in turn results in a small change in the output
format, since previously, the secondary messages were represented as
just another snippet. We use sub-diagnostics because that's the intended
way to enforce relative ordering between messages within a diagnostic.

* The "info:" prefix used in some annotation messages has been dropped.
We could re-add this, but I think I like it better without this prefix.

I believe those 3 cover all of the snapshot changes here.
2025-03-17 12:46:49 -04:00
Douglas Creager 23ccb52fa6
[red-knot] Handle unions of callables better (#16716)
This cleans up how we handle calling unions of types. #16568 adding a
three-level structure for callable signatures (`Signatures`,
`CallableSignature`, and `Signature`) to handle unions and overloads.

This PR updates the bindings side to mimic that structure. What used to
be called `CallOutcome` is now `Bindings`, and represents the result of
binding actual arguments against a possible union of callables.
`CallableBinding` is the result of binding a single, possibly
overloaded, callable type. `Binding` is the result of binding a single
overload.

While we're here, this also cleans up `CallError` greatly. It was
previously extracting error information from the bindings and storing it
in the error result. It is now a simple enum, carrying no data, that's
used as a status code to talk about whether the overall binding was
successful or not. We are now more consistent about walking the binding
itself to get detailed information about _how_ the binding was
unsucessful.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-17 10:35:52 -04:00
Dhruv Manilawala 3ccc8dbbf9
[red-knot] Fix fully static check for callable type (#16803)
## Summary

This PR fixes a bug in the check for fully static callable type where we
would skip unannotated parameter type.

## Test Plan

Add tests using the new `CallableTypeFromFunction` special form.
2025-03-17 20:01:30 +05:30
Alex Waygood 50b66dc025
[red-knot] Stabilize `negation_reverses_subtype_order` property test (#16801)
## Summary

This is a re-creation of https://github.com/astral-sh/ruff/pull/16764 by
@mtshiba, which I closed meaning to immediately reopen (GitHub wasn't
updating the PR with the latest pushed changes), and which GitHub will
not allow me to reopen for some reason. Pasting the summary from that PR
below:

> From https://github.com/astral-sh/ruff/pull/16641
> 
> As stated in this comment
(https://github.com/astral-sh/ruff/pull/16641#discussion_r1996153702),
the current ordering implementation for intersection types is incorrect.
So, I will introduce lexicographic ordering for intersection types.

## Test Plan

One property test stabilised (tested locally with
`QUICKCHECK_TESTS=2000000 cargo test --release -p
red_knot_python_semantic -- --ignored
types::property_tests::stable::negation_reverses_subtype_order`), and
existing mdtests that previously failed now pass.

Primarily-authored-by:
[mtshiba](https://github.com/astral-sh/ruff/commits?author=mtshiba)

---------

Co-authored-by: Shunsuke Shibayama <sbym1346@gmail.com>
2025-03-17 12:33:38 +00:00
Matthew Mckee 24707777af
[red-knot] Emit error if int/float/complex/bytes/boolean literals appear in type expressions outside `typing.Literal[]` (#16765)
## Summary
Fixes https://github.com/astral-sh/ruff/issues/16532

## Test Plan

New mdtest assertions added

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-03-17 11:56:16 +00:00
Micha Reiser c100d519e9
[internal]: Upgrade salsa (#16794)
## Summary

Another salsa upgrade. 

The main motivation is to stay on a recent salsa version because there
are still a lot of breaking changes happening.
The most significant changes in this update:

* Salsa no longer derives `Debug` by default. It now requires
`interned(debug)` (or similar)
* This version ships the foundation for garbage collecting interned
values. However, this comes at the cost that queries now track which
interned values they created (or read). The micro benchmarks in the
salsa repo showed a significant perf regression. Will see if this also
visible in our benchmarks.

## Test Plan

`cargo test`
2025-03-17 11:05:54 +01:00
David Peter ebcad6e641
[red-knot] Use `try_call_dunder` for augmented assignment (#16717)
## Summary

Uses the `try_call_dunder` infrastructure for augmented assignment and
fixes the logic to work for types other than `Type::Instance(…)`. This
allows us to infer the correct type here:
```py
x = (1, 2)
x += (3, 4)
reveal_type(x)  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
```
Or in this (extremely weird) scenario:
```py
class Meta(type):
    def __iadd__(cls, other: int) -> str:
        return ""

class C(metaclass=Meta): ...

cls = C
cls += 1

reveal_type(cls)  # revealed: str
```

Union and intersection handling could also be improved here, but I made
no attempt to do so in this PR.

## Test Plan

New MD tests
2025-03-14 20:36:09 +01:00
David Peter fe275725e0
[red-knot] Document current state of attribute assignment diagnostics (#16746)
## Summary

A follow-up to https://github.com/astral-sh/ruff/pull/16705 which
documents various kinds of diagnostics that can appear when assigning to
an attribute.

## Test Plan

New snapshot tests.
2025-03-14 20:34:43 +01:00
Micha Reiser a467e7c8d3
[red-knot] Case sensitive module resolver (#16521)
## Summary

This PR implements the first part of
https://github.com/astral-sh/ruff/discussions/16440. It ensures that Red
Knot's module resolver is case sensitive on all systems.

This PR combines a few approaches:

1. It uses `canonicalize` on non-case-sensitive systems to get the real
casing of a path. This works for as long as no symlinks or mapped
network drives (the windows `E:\` is mapped to `\\server\share` thingy).
This is the same as what Pyright does
2. If 1. fails, fall back to recursively list the parent directory and
test if the path's file name matches the casing exactly as listed in by
list dir. This is the same approach as CPython takes in its module
resolver. The main downside is that it requires more syscalls because,
unlike CPython, we Red Knot needs to invalidate its caches if a file
name gets renamed (CPython assumes that the folders are immutable).

It's worth noting that the file watching test that I added that renames
`lib.py` to `Lib.py` currently doesn't pass on case-insensitive systems.
Making it pass requires some more involved changes to `Files`. I plan to
work on this next. There's the argument that landing this PR on its own
isn't worth it without this issue being addressed. I think it's still a
good step in the right direction even when some of the details on how
and where the path case sensitive comparison is implemented.

## Test plan

I added multiple integration tests (including a failing one). I tested
that the `case-sensitivity` detection works as expected on Windows,
MacOS and Linux and that the fast-paths are taken accordingly.
2025-03-14 19:16:44 +00:00
David Peter a22d206db2
[red-knot] Preliminary tests for typing.Final (#15917)
## Summary

WIP.

Adds some preliminary tests for `typing.Final`.

## Test Plan

New MD tests
2025-03-14 12:30:13 +01:00
cake-monotone 270318c2e0
[red-knot] fix: improve type inference for binary ops on tuples (#16725)
## Summary

This PR includes minor improvements to binary operation inference,
specifically for tuple concatenation.

### Before

```py
reveal_type((1, 2) + (3, 4))  # revealed: @Todo(return type of decorated function)
# If TODO is ignored, the revealed type would be `tuple[1|2|3|4, ...]`
```

The `builtins.tuple` type stub defines `__add__`, but it appears to only
work for homogeneous tuples. However, I think this limitation is not
ideal for many use cases.

### After

```py
reveal_type((1, 2) + (3, 4))  # revealed: tuple[Literal[1], Literal[2], Literal[3], Literal[4]]
```

## Test Plan

### Added
- `mdtest/binary/tuples.md`

### Affected
- `mdtest/slots.md` (a test have been moved out of the `False-Negative`
block.)
2025-03-14 12:29:57 +01:00
David Peter d03b12e711
[red-knot] Assignments to attributes (#16705)
## Summary

This changeset adds proper support for assignments to attributes:
```py
obj.attr = value
```

In particular, the following new features are now available:

* We previously didn't raise any errors if you tried to assign to a
non-existing attribute `attr`. This is now fixed.
* If `type(obj).attr` is a data descriptor, we now call its `__set__`
method instead of trying to assign to the load-context type of
`obj.attr`, which can be different for data descriptors.
* An initial attempt was made to support unions and intersections, as
well as possibly-unbound situations. There are some remaining TODOs in
tests, but they only affect edge cases. Having nested diagnostics would
be one way that could help solve the remaining cases, I believe.

## Follow ups

The following things are planned as follow-ups:

- Write a test suite with snapshot diagnostics for various attribute
assignment errors
- Improve the diagnostics. An easy improvement would be to highlight the
right hand side of the assignment as a secondary span (with the rhs type
as additional information). Some other ideas are mentioned in TODO
comments in this PR.
- Improve the union/intersection/possible-unboundness handling
- Add support for calling custom `__setattr__` methods (see new false
positive in the ecosystem results)

## Ecosystem changes

Some changes are related to assignments on attributes with a custom
`__setattr__` method (see above). Since we didn't notice missing
attributes at all in store context previously, these are new.

The other changes are related to properties. We previously used their
read-context type to test the assignment. That results in weird error
messages, as we often see assignments to `self.property` and then we
think that those are instance attributes *and* descriptors, leading to
union types. Now we properly look them up on the meta type, see the
decorated function, and try to overwrite it with the new value (as we
don't understand decorators yet). Long story short: the errors are still
weird, we need to understand decorators to make them go away.

## Test Plan

New Markdown tests
2025-03-14 12:15:41 +01:00
Carl Meyer abaa18993b
[red-knot] handle cycles in MRO/bases resolution (#16693)
There can be semi-cyclic inheritance patterns (e.g. recursive generics)
that are not technically inheritance cycles, but that can cause us to
hit Salsa query cycles in evaluating a type's MRO. Add fixed-point
handling to these MRO-related queries so we don't panic on these cycles.

The details of what queries we hit in what order in this case will
change as we implement support for generics, but ultimately we will
probably need cycle handling for all queries that can re-enter type
inference, otherwise we are susceptible to small changes in query
execution order causing panics.

Fixes #14333
Further reduces the panicking set of seeds in #14737
2025-03-13 08:16:03 -07:00
Dhruv Manilawala 58d5fe982e
[red-knot] Check gradual equivalence between callable types (#16634) 2025-03-13 08:16:51 +05:30
Dhruv Manilawala 08fa9b4a90
[red-knot] Add `CallableTypeFromFunction` special form (#16683)
## Summary

This PR adds a new `CallableTypeFromFunction` special form to allow
extracting the abstract signature of a function literal i.e., convert a
`Type::Function` into a `Type::Callable` (`CallableType::General`).

This is done to support testing the `is_gradual_equivalent_to` type
relation specifically the case we want to make sure that a function that
has parameters with no annotations and does not have a return type
annotation is gradual equivalent to `Callable[[Any, Any, ...], Any]`
where the number of parameters should match between the function literal
and callable type.

Refer
https://github.com/astral-sh/ruff/pull/16634#discussion_r1989976692

### Bikeshedding

The name `CallableTypeFromFunction` is a bit too verbose. A possibly
alternative from Carl is `CallableTypeOf` but that would be similar to
`TypeOf` albeit with a limitation that the former only accepts function
literal types and errors on other types.

Some other alternatives:
* `FunctionSignature`
* `SignatureOf` (similar issues as `TypeOf`?)
* ...

## Test Plan

Update `type_api.md` with a new section that tests this special form,
both invalid and valid forms.
2025-03-13 07:49:34 +05:30
David Peter 083df0cf84
[red-knot] Support custom `__getattr__` methods (#16668)
## Summary

Add support for calling custom `__getattr__` methods in case an
attribute is not otherwise found. This allows us to get rid of many
ecosystem false positives where we previously emitted errors when
accessing attributes on `argparse.Namespace`.

closes #16614

## Test Plan

* New Markdown tests
* Observed expected ecosystem changes (the changes for `arrow` also look
fine, since the `Arrow` class has a custom [`__getattr__`
here](1d70d00919/arrow/arrow.py (L802-L815)))
2025-03-12 13:44:11 +01:00
Carl Meyer a176c1ac80
[red-knot] use fixpoint iteration for all cycles (#14029)
Pulls in the latest Salsa main branch, which supports fixpoint
iteration, and uses it to handle all query cycles.

With this, we no longer need to skip any corpus files to avoid panics.

Latest perf results show a 6% incremental and 1% cold-check regression.
This is not a "no cycles" regression, as tomllib and typeshed do trigger
some definition cycles (previously handled by our old
`infer_definition_types` fallback to `Unknown`). We don't currently have
a benchmark we can use to measure the pure no-cycles regression, though
I expect there would still be some regression; the fixpoint iteration
feature in Salsa does add some overhead even for non-cyclic queries.

I think this regression is within the reasonable range for this feature.
We can do further optimization work later, but I don't think it's the
top priority right now. So going ahead and acknowledging the regression
on CodSpeed.

Mypy primer is happy, so this doesn't regress anything on our
currently-checked projects. I expect it probably unlocks adding a number
of new projects to our ecosystem check that previously would have
panicked.

Fixes #13792
Fixes #14672
2025-03-12 12:41:40 +00:00
David Peter a6572a57c4
[red-knot] Attribute access on intersection types (#16665)
## Summary

Implements attribute access on intersection types, which didn't
previously work. For example:

```py
from typing import Any

class P: ...
class Q: ...

class A:
    x: P = P()

class B:
    x: Any = Q()

def _(obj: A):
    if isinstance(obj, B):
        reveal_type(obj.x)  # revealed: P & Any
```

Refers to [this comment].

[this comment]:
https://github.com/astral-sh/ruff/pull/16416#discussion_r1985040363

## Test Plan

New Markdown tests
2025-03-12 13:20:17 +01:00
Joey Bar b250304ad3
[red-knot] Improve is_disjoint for two intersections (#16636)
## Summary

Background - as a follow up to #16611 I noticed that there's a lot of
code duplicated between the `is_assignable_to` and `is_subtype_of`
functions and considered trying to merge them.

[A subtype and an assignable type are pretty much the
same](https://typing.python.org/en/latest/spec/concepts.html#the-assignable-to-or-consistent-subtyping-relation),
except that subtypes are by definition fully static, so I think we can
replace the whole of `is_subtype_of` with:

```
if !self.is_fully_static(db) || !target.is_fully_static(db) {
    return false;
}
return self.is_assignable_to(target)
```

if we move all of the logic to is_assignable_to and delete duplicate
code. Then we can discuss if it even makes sense to have a separate
is_subtype_of function (I think the answer is yes since it's used by a
bunch of other places, but we may be able to basically rip out the
concept).

Anyways while playing with combining the functions I noticed is that the
handling of Intersections in `is_subtype_of` has a special case for two
intersections, which I didn't include in the last PR - rather I first
handled right hand intersections before left hand, which should properly
handle double intersections (hand-wavy explanation I can justify if
needed - (A & B & C) is assignable to (A & B) because the left is
assignable to both A and B, but none of A, B, or C is assignable to (A &
B)).

I took a look at what breaks if I remove the handling for double
intersections, and the reason it is needed is because is_disjoint does
not properly handle intersections with negative conditions (so instead
`is_subtype_of` basically implements the check correctly).

This PR adds support to is_disjoint for properly checking negative
branches, which also lets us simplify `is_subtype_of`, bringing it in
line with `is_assignable_to`

## Test Plan

Added a bunch of tests, most of which failed before this fix

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-12 12:13:04 +00:00
David Peter 11b5cbcd2f
[red-knot] Restructure attribute-access and descriptor-protocol test suites. (#16664)
## Summary

This is a pure restructuring of the `attributes.md` and
`descriptor_protocol.md` test suites. They have grown organically and I
didn't want to make major structural changes in my recent PR to keep the
diff clean.
2025-03-12 09:52:21 +01:00
David Peter 3228545598
[red-knot] Minor optimization/cleanup in member lookup (#16663)
## Summary

A follow up to address [this comment]:

> Similarly here, it might be a little more performant to have a single
`Type::instance()` branch with an inner match over `class.known()`
rather than having multiple branches with `if class.is_known()` guards

[this comment]:
https://github.com/astral-sh/ruff/pull/16416#discussion_r1985159037
2025-03-12 09:11:05 +01:00
David Peter 860b95a318
[red-knot] Binary operator inference for union types (#16601)
## Summary

Properly handle binary operator inference for union types.

This fixes a bug I noticed while looking at ecosystem results. The MRE
version of it is this:

```py
def sub(x: float, y: float):
    # Red Knot: Operator `-` is unsupported between objects of type `int | float` and `int | float`
    return x - y
```

## Test Plan

- New Markdown tests.
- Expected diff in the ecosystem checks
2025-03-12 08:21:54 +01:00
Dhruv Manilawala 6de2b2873b
[red-knot] Check if callable type is fully static (#16633)
## Summary

Part of #15382 

This PR adds the check for whether a callable type is fully static or
not.

A callable type is fully static if all of the parameter types are fully
static _and_ the return type is fully static _and_ if it does not use
the gradual form (`...`) for its parameters.

## Test Plan

Update `is_fully_static.md` with callable types.

It seems that currently this test is grouped into either fully static or
not, I think it would be useful to split them up in groups like
callable, etc. I intentionally avoided that in this PR but I'll put up a
PR for an appropriate split.

Note: I've an explicit goal of updating the property tests with the new
callable types once all relations are implemented.
2025-03-12 12:13:22 +05:30
Dhruv Manilawala 6b84253679
[red-knot] Callable member lookup, meta type impl (#16618)
## Summary

This PR is a follow-up to https://github.com/astral-sh/ruff/pull/16493
that implements member lookup for the general callable type.

Based on the discussion around [member lookup
here](https://github.com/astral-sh/ruff/pull/16493#discussion_r1982041180)
and [`.to_meta_type()`
here](https://github.com/astral-sh/ruff/pull/16493#discussion_r1985104664).

## Test Plan

Add a new test cases.
2025-03-12 12:01:38 +05:30
Carl Meyer 0340e23395
[red-knot] remove redundant sentence in test (#16660)
Removes a redundant sentence I accidentally left in the test suite from
in #16540 (my mistake).
2025-03-12 04:20:31 +00:00
Shunsuke Shibayama 78b5f0b165
[red-knot] detect invalid return type (#16540)
## Summary

This PR closes #16248.

If the return type of the function isn't assignable to the one
specified, an `invalid-return-type` error occurs.
I thought it would be better to report this as a different kind of error
than the `invalid-assignment` error, so I defined this as a new error.

## Test Plan

All type inconsistencies in the test cases have been replaced with
appropriate ones.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-12 01:58:59 +00:00
Douglas Creager e17cd350b6
[red-knot] Support multiple overloads when binding parameters at call sites (#16568)
This updates the `Signature` and `CallBinding` machinery to support
multiple overloads for a callable. This is currently only used for
`KnownFunction`s that we special-case in our type inference code. It
does **_not_** yet update the semantic index builder to handle
`@overload` decorators and construct a multi-signature `Overloads`
instance for real Python functions.

While I was here, I updated many of the `try_call` special cases to use
signatures (possibly overloaded ones now) and `bind_call` to check
parameter lists. We still need some of the mutator methods on
`OverloadBinding` for the special cases where we need to update return
types based on some Rust code.
2025-03-11 15:08:17 -04:00
Alex Waygood c16237ddc0
[red-knot] Rework `Type::to_instance()` to return `Option<Type>` (#16428)
## Summary

This PR fixes https://github.com/astral-sh/ruff/issues/16302.

The PR reworks `Type::to_instance()` to return `Option<Type>` rather
than `Type`. This reflects more accurately the fact that some variants
cannot be "turned into an instance", since they _already_ represent
instances of some kind. On `main`, we silently fallback to `Unknown` for
these variants, but this implicit behaviour can be somewhat surprising
and lead to unexpected bugs.

Returning `Option<Type>` rather than `Type` means that each callsite has
to account for the possibility that the type might already represent an
instance, and decide what to do about it.
In general, I think this increases the robustness of the code. Working
on this PR revealed two latent bugs in the code:
- One which has already been fixed by
https://github.com/astral-sh/ruff/pull/16427
- One which is fixed as part of https://github.com/astral-sh/ruff/pull/16608

I added special handling to `KnownClass::to_instance()`: If we fail to find one of these classes and the `test` feature is
_not_ enabled, we log a warning to the terminal saying that we failed to
find the class in typeshed and that we will be falling back to
`Type::Unknown`. A cache is maintained so that we record all classes
that we have already logged a warning for; we only log a warning for
failing to lookup a `KnownClass` if we know that it's the first time
we're looking it up.

## Test Plan

- All existing tests pass
- I ran the property tests via `QUICKCHECK_TESTS=1000000 cargo test
--release -p red_knot_python_semantic -- --ignored
types::property_tests::stable`

I also manually checked that warnings are appropriately printed to the
terminal when `KnownClass::to_instance()` falls back to `Unknown` and
the `test` feature is not enabled. To do this, I applied this diff to
the PR branch:

<details>
<summary>Patch deleting `int` and `str` from buitins</summary>

```diff
diff --git a/crates/red_knot_vendored/vendor/typeshed/stdlib/builtins.pyi b/crates/red_knot_vendored/vendor/typeshed/stdlib/builtins.pyi
index 0a6dc57b0..86636a05b 100644
--- a/crates/red_knot_vendored/vendor/typeshed/stdlib/builtins.pyi
+++ b/crates/red_knot_vendored/vendor/typeshed/stdlib/builtins.pyi
@@ -228,111 +228,6 @@ _PositiveInteger: TypeAlias = Literal[1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,
 _NegativeInteger: TypeAlias = Literal[-1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15, -16, -17, -18, -19, -20]
 _LiteralInteger = _PositiveInteger | _NegativeInteger | Literal[0]  # noqa: Y026  # TODO: Use TypeAlias once mypy bugs are fixed
 
-class int:
-    @overload
-    def __new__(cls, x: ConvertibleToInt = ..., /) -> Self: ...
-    @overload
-    def __new__(cls, x: str | bytes | bytearray, /, base: SupportsIndex) -> Self: ...
-    def as_integer_ratio(self) -> tuple[int, Literal[1]]: ...
-    @property
-    def real(self) -> int: ...
-    @property
-    def imag(self) -> Literal[0]: ...
-    @property
-    def numerator(self) -> int: ...
-    @property
-    def denominator(self) -> Literal[1]: ...
-    def conjugate(self) -> int: ...
-    def bit_length(self) -> int: ...
-    if sys.version_info >= (3, 10):
-        def bit_count(self) -> int: ...
-
-    if sys.version_info >= (3, 11):
-        def to_bytes(
-            self, length: SupportsIndex = 1, byteorder: Literal["little", "big"] = "big", *, signed: bool = False
-        ) -> bytes: ...
-        @classmethod
-        def from_bytes(
-            cls,
-            bytes: Iterable[SupportsIndex] | SupportsBytes | ReadableBuffer,
-            byteorder: Literal["little", "big"] = "big",
-            *,
-            signed: bool = False,
-        ) -> Self: ...
-    else:
-        def to_bytes(self, length: SupportsIndex, byteorder: Literal["little", "big"], *, signed: bool = False) -> bytes: ...
-        @classmethod
-        def from_bytes(
-            cls,
-            bytes: Iterable[SupportsIndex] | SupportsBytes | ReadableBuffer,
-            byteorder: Literal["little", "big"],
-            *,
-            signed: bool = False,
-        ) -> Self: ...
-
-    if sys.version_info >= (3, 12):
-        def is_integer(self) -> Literal[True]: ...
-
-    def __add__(self, value: int, /) -> int: ...
-    def __sub__(self, value: int, /) -> int: ...
-    def __mul__(self, value: int, /) -> int: ...
-    def __floordiv__(self, value: int, /) -> int: ...
-    def __truediv__(self, value: int, /) -> float: ...
-    def __mod__(self, value: int, /) -> int: ...
-    def __divmod__(self, value: int, /) -> tuple[int, int]: ...
-    def __radd__(self, value: int, /) -> int: ...
-    def __rsub__(self, value: int, /) -> int: ...
-    def __rmul__(self, value: int, /) -> int: ...
-    def __rfloordiv__(self, value: int, /) -> int: ...
-    def __rtruediv__(self, value: int, /) -> float: ...
-    def __rmod__(self, value: int, /) -> int: ...
-    def __rdivmod__(self, value: int, /) -> tuple[int, int]: ...
-    @overload
-    def __pow__(self, x: Literal[0], /) -> Literal[1]: ...
-    @overload
-    def __pow__(self, value: Literal[0], mod: None, /) -> Literal[1]: ...
-    @overload
-    def __pow__(self, value: _PositiveInteger, mod: None = None, /) -> int: ...
-    @overload
-    def __pow__(self, value: _NegativeInteger, mod: None = None, /) -> float: ...
-    # positive __value -> int; negative __value -> float
-    # return type must be Any as `int | float` causes too many false-positive errors
-    @overload
-    def __pow__(self, value: int, mod: None = None, /) -> Any: ...
-    @overload
-    def __pow__(self, value: int, mod: int, /) -> int: ...
-    def __rpow__(self, value: int, mod: int | None = None, /) -> Any: ...
-    def __and__(self, value: int, /) -> int: ...
-    def __or__(self, value: int, /) -> int: ...
-    def __xor__(self, value: int, /) -> int: ...
-    def __lshift__(self, value: int, /) -> int: ...
-    def __rshift__(self, value: int, /) -> int: ...
-    def __rand__(self, value: int, /) -> int: ...
-    def __ror__(self, value: int, /) -> int: ...
-    def __rxor__(self, value: int, /) -> int: ...
-    def __rlshift__(self, value: int, /) -> int: ...
-    def __rrshift__(self, value: int, /) -> int: ...
-    def __neg__(self) -> int: ...
-    def __pos__(self) -> int: ...
-    def __invert__(self) -> int: ...
-    def __trunc__(self) -> int: ...
-    def __ceil__(self) -> int: ...
-    def __floor__(self) -> int: ...
-    def __round__(self, ndigits: SupportsIndex = ..., /) -> int: ...
-    def __getnewargs__(self) -> tuple[int]: ...
-    def __eq__(self, value: object, /) -> bool: ...
-    def __ne__(self, value: object, /) -> bool: ...
-    def __lt__(self, value: int, /) -> bool: ...
-    def __le__(self, value: int, /) -> bool: ...
-    def __gt__(self, value: int, /) -> bool: ...
-    def __ge__(self, value: int, /) -> bool: ...
-    def __float__(self) -> float: ...
-    def __int__(self) -> int: ...
-    def __abs__(self) -> int: ...
-    def __hash__(self) -> int: ...
-    def __bool__(self) -> bool: ...
-    def __index__(self) -> int: ...
-
 class float:
     def __new__(cls, x: ConvertibleToFloat = ..., /) -> Self: ...
     def as_integer_ratio(self) -> tuple[int, int]: ...
@@ -437,190 +332,6 @@ class _FormatMapMapping(Protocol):
 class _TranslateTable(Protocol):
     def __getitem__(self, key: int, /) -> str | int | None: ...
 
-class str(Sequence[str]):
-    @overload
-    def __new__(cls, object: object = ...) -> Self: ...
-    @overload
-    def __new__(cls, object: ReadableBuffer, encoding: str = ..., errors: str = ...) -> Self: ...
-    @overload
-    def capitalize(self: LiteralString) -> LiteralString: ...
-    @overload
-    def capitalize(self) -> str: ...  # type: ignore[misc]
-    @overload
-    def casefold(self: LiteralString) -> LiteralString: ...
-    @overload
-    def casefold(self) -> str: ...  # type: ignore[misc]
-    @overload
-    def center(self: LiteralString, width: SupportsIndex, fillchar: LiteralString = " ", /) -> LiteralString: ...
-    @overload
-    def center(self, width: SupportsIndex, fillchar: str = " ", /) -> str: ...  # type: ignore[misc]
-    def count(self, sub: str, start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /) -> int: ...
-    def encode(self, encoding: str = "utf-8", errors: str = "strict") -> bytes: ...
-    def endswith(
-        self, suffix: str | tuple[str, ...], start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /
-    ) -> bool: ...
-    @overload
-    def expandtabs(self: LiteralString, tabsize: SupportsIndex = 8) -> LiteralString: ...
-    @overload
-    def expandtabs(self, tabsize: SupportsIndex = 8) -> str: ...  # type: ignore[misc]
-    def find(self, sub: str, start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /) -> int: ...
-    @overload
-    def format(self: LiteralString, *args: LiteralString, **kwargs: LiteralString) -> LiteralString: ...
-    @overload
-    def format(self, *args: object, **kwargs: object) -> str: ...
-    def format_map(self, mapping: _FormatMapMapping, /) -> str: ...
-    def index(self, sub: str, start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /) -> int: ...
-    def isalnum(self) -> bool: ...
-    def isalpha(self) -> bool: ...
-    def isascii(self) -> bool: ...
-    def isdecimal(self) -> bool: ...
-    def isdigit(self) -> bool: ...
-    def isidentifier(self) -> bool: ...
-    def islower(self) -> bool: ...
-    def isnumeric(self) -> bool: ...
-    def isprintable(self) -> bool: ...
-    def isspace(self) -> bool: ...
-    def istitle(self) -> bool: ...
-    def isupper(self) -> bool: ...
-    @overload
-    def join(self: LiteralString, iterable: Iterable[LiteralString], /) -> LiteralString: ...
-    @overload
-    def join(self, iterable: Iterable[str], /) -> str: ...  # type: ignore[misc]
-    @overload
-    def ljust(self: LiteralString, width: SupportsIndex, fillchar: LiteralString = " ", /) -> LiteralString: ...
-    @overload
-    def ljust(self, width: SupportsIndex, fillchar: str = " ", /) -> str: ...  # type: ignore[misc]
-    @overload
-    def lower(self: LiteralString) -> LiteralString: ...
-    @overload
-    def lower(self) -> str: ...  # type: ignore[misc]
-    @overload
-    def lstrip(self: LiteralString, chars: LiteralString | None = None, /) -> LiteralString: ...
-    @overload
-    def lstrip(self, chars: str | None = None, /) -> str: ...  # type: ignore[misc]
-    @overload
-    def partition(self: LiteralString, sep: LiteralString, /) -> tuple[LiteralString, LiteralString, LiteralString]: ...
-    @overload
-    def partition(self, sep: str, /) -> tuple[str, str, str]: ...  # type: ignore[misc]
-    if sys.version_info >= (3, 13):
-        @overload
-        def replace(
-            self: LiteralString, old: LiteralString, new: LiteralString, /, count: SupportsIndex = -1
-        ) -> LiteralString: ...
-        @overload
-        def replace(self, old: str, new: str, /, count: SupportsIndex = -1) -> str: ...  # type: ignore[misc]
-    else:
-        @overload
-        def replace(
-            self: LiteralString, old: LiteralString, new: LiteralString, count: SupportsIndex = -1, /
-        ) -> LiteralString: ...
-        @overload
-        def replace(self, old: str, new: str, count: SupportsIndex = -1, /) -> str: ...  # type: ignore[misc]
-    if sys.version_info >= (3, 9):
-        @overload
-        def removeprefix(self: LiteralString, prefix: LiteralString, /) -> LiteralString: ...
-        @overload
-        def removeprefix(self, prefix: str, /) -> str: ...  # type: ignore[misc]
-        @overload
-        def removesuffix(self: LiteralString, suffix: LiteralString, /) -> LiteralString: ...
-        @overload
-        def removesuffix(self, suffix: str, /) -> str: ...  # type: ignore[misc]
-
-    def rfind(self, sub: str, start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /) -> int: ...
-    def rindex(self, sub: str, start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /) -> int: ...
-    @overload
-    def rjust(self: LiteralString, width: SupportsIndex, fillchar: LiteralString = " ", /) -> LiteralString: ...
-    @overload
-    def rjust(self, width: SupportsIndex, fillchar: str = " ", /) -> str: ...  # type: ignore[misc]
-    @overload
-    def rpartition(self: LiteralString, sep: LiteralString, /) -> tuple[LiteralString, LiteralString, LiteralString]: ...
-    @overload
-    def rpartition(self, sep: str, /) -> tuple[str, str, str]: ...  # type: ignore[misc]
-    @overload
-    def rsplit(self: LiteralString, sep: LiteralString | None = None, maxsplit: SupportsIndex = -1) -> list[LiteralString]: ...
-    @overload
-    def rsplit(self, sep: str | None = None, maxsplit: SupportsIndex = -1) -> list[str]: ...  # type: ignore[misc]
-    @overload
-    def rstrip(self: LiteralString, chars: LiteralString | None = None, /) -> LiteralString: ...
-    @overload
-    def rstrip(self, chars: str | None = None, /) -> str: ...  # type: ignore[misc]
-    @overload
-    def split(self: LiteralString, sep: LiteralString | None = None, maxsplit: SupportsIndex = -1) -> list[LiteralString]: ...
-    @overload
-    def split(self, sep: str | None = None, maxsplit: SupportsIndex = -1) -> list[str]: ...  # type: ignore[misc]
-    @overload
-    def splitlines(self: LiteralString, keepends: bool = False) -> list[LiteralString]: ...
-    @overload
-    def splitlines(self, keepends: bool = False) -> list[str]: ...  # type: ignore[misc]
-    def startswith(
-        self, prefix: str | tuple[str, ...], start: SupportsIndex | None = ..., end: SupportsIndex | None = ..., /
-    ) -> bool: ...
-    @overload
-    def strip(self: LiteralString, chars: LiteralString | None = None, /) -> LiteralString: ...
-    @overload
-    def strip(self, chars: str | None = None, /) -> str: ...  # type: ignore[misc]
-    @overload
-    def swapcase(self: LiteralString) -> LiteralString: ...
-    @overload
-    def swapcase(self) -> str: ...  # type: ignore[misc]
-    @overload
-    def title(self: LiteralString) -> LiteralString: ...
-    @overload
-    def title(self) -> str: ...  # type: ignore[misc]
-    def translate(self, table: _TranslateTable, /) -> str: ...
-    @overload
-    def upper(self: LiteralString) -> LiteralString: ...
-    @overload
-    def upper(self) -> str: ...  # type: ignore[misc]
-    @overload
-    def zfill(self: LiteralString, width: SupportsIndex, /) -> LiteralString: ...
-    @overload
-    def zfill(self, width: SupportsIndex, /) -> str: ...  # type: ignore[misc]
-    @staticmethod
-    @overload
-    def maketrans(x: dict[int, _T] | dict[str, _T] | dict[str | int, _T], /) -> dict[int, _T]: ...
-    @staticmethod
-    @overload
-    def maketrans(x: str, y: str, /) -> dict[int, int]: ...
-    @staticmethod
-    @overload
-    def maketrans(x: str, y: str, z: str, /) -> dict[int, int | None]: ...
-    @overload
-    def __add__(self: LiteralString, value: LiteralString, /) -> LiteralString: ...
-    @overload
-    def __add__(self, value: str, /) -> str: ...  # type: ignore[misc]
-    # Incompatible with Sequence.__contains__
-    def __contains__(self, key: str, /) -> bool: ...  # type: ignore[override]
-    def __eq__(self, value: object, /) -> bool: ...
-    def __ge__(self, value: str, /) -> bool: ...
-    @overload
-    def __getitem__(self: LiteralString, key: SupportsIndex | slice, /) -> LiteralString: ...
-    @overload
-    def __getitem__(self, key: SupportsIndex | slice, /) -> str: ...  # type: ignore[misc]
-    def __gt__(self, value: str, /) -> bool: ...
-    def __hash__(self) -> int: ...
-    @overload
-    def __iter__(self: LiteralString) -> Iterator[LiteralString]: ...
-    @overload
-    def __iter__(self) -> Iterator[str]: ...  # type: ignore[misc]
-    def __le__(self, value: str, /) -> bool: ...
-    def __len__(self) -> int: ...
-    def __lt__(self, value: str, /) -> bool: ...
-    @overload
-    def __mod__(self: LiteralString, value: LiteralString | tuple[LiteralString, ...], /) -> LiteralString: ...
-    @overload
-    def __mod__(self, value: Any, /) -> str: ...
-    @overload
-    def __mul__(self: LiteralString, value: SupportsIndex, /) -> LiteralString: ...
-    @overload
-    def __mul__(self, value: SupportsIndex, /) -> str: ...  # type: ignore[misc]
-    def __ne__(self, value: object, /) -> bool: ...
-    @overload
-    def __rmul__(self: LiteralString, value: SupportsIndex, /) -> LiteralString: ...
-    @overload
-    def __rmul__(self, value: SupportsIndex, /) -> str: ...  # type: ignore[misc]
-    def __getnewargs__(self) -> tuple[str]: ...
-
 class bytes(Sequence[int]):
```

</details>

And then ran red-knot on my
[typeshed-stats](https://github.com/AlexWaygood/typeshed-stats) project
using the command

```
cargo run -p red_knot -- check --project ../typeshed-stats --python-version="3.12" --verbose
```

I observed that the following logs were printed to the terminal, but
that each warning was only printed once (the desired behaviour):

```
INFO Python version: Python 3.12, platform: all
INFO Indexed 15 file(s)
INFO Could not find class `builtins.int` in typeshed on Python 3.12. Falling back to `Unknown` for the symbol instead.
INFO Could not find class `builtins.str` in typeshed on Python 3.12. Falling back to `Unknown` for the symbol instead.
```
2025-03-11 16:42:44 +00:00
Alex Waygood 989075dc16
[red-knot] Add tests asserting that `KnownClass::to_instance()` doesn't unexpectedly fallback to `Type::Unknown` with full typeshed stubs (#16608)
## Summary

One of the motivations in https://github.com/astral-sh/ruff/pull/16428
for panicking when the `test` or `debug_assertions` features are enabled
and a lookup of a `KnownClass` fails is that we've had some latent bugs
in our code where certain variants have been silently falling back to
`Unknown` in every typeshed lookup without us realising. But that in
itself isn't a great motivation for panicking in
`KnownClass::to_instance()`, since we can fairly easily add some tests
that assert that we don't unexpectedly fallback to `Unknown` for any
`KnownClass` variant. This PR adds those tests.

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-03-11 16:12:44 +00:00
Joey Bar e8e24310fb
[red-knot] Handle gradual intersection types in assignability (#16611)
## Summary

This mostly fixes #14899

My motivation was similar to the last comment by @sharkdp there. I ran
red_knot on a codebase and the most common error was patterns like this
failing:

```
def foo(x: str): ...

x: Any = ...
if isinstance(x, str):
    foo(x) # Object of type `Any & str` cannot be assigned to parameter 1 (`x`) of function `foo`; expected type `str`
```

The desired behavior is pretty much to ignore Any/Unknown when resolving
intersection assignability - `Any & str` should be assignable to `str`,
and `str` should be assignable to `str & Any`
 
The fix is actually very similar to the existing code in
`is_subtype_of`, we need to correctly handle intersections on either
side, while being careful to handle dynamic types as desired.

This does not fix the second test case from that issue:

```
static_assert(is_assignable_to(Intersection[Unrelated, Any], Not[tuple[Unrelated, Any]]))
```

but that's misleading because the root cause there has nothing to do
with gradual types. I added a simpler test case that also fails:

```
static_assert(is_assignable_to(Unrelated, Not[tuple[Unrelated]]))
```
This is because we don't determine that Unrelated does not subclass from
tuple so we can't rule out this relation. If that logic is improved then
this fix should also handle the case of the intersection

## Test Plan

Added a bunch of is_assignable_to tests, most of which failed before
this fix.
2025-03-11 07:58:56 -07:00
Dhruv Manilawala da069aa00c
[red-knot] Infer `lambda` expression (#16547)
## Summary

Part of https://github.com/astral-sh/ruff/issues/15382

This PR adds support for inferring the `lambda` expression and return
the `CallableType`.

Currently, this is only limited to inferring the parameters and a todo
type for the return type.

For posterity, I tried using the `file_expression_type` to infer the
return type of lambda but it would always lead to cycle. The main reason
is that in `infer_parameter_definition`, the default expression is being
inferred using `file_expression_type`, which is correct, but it then

Take the following source code as an example:
```py
lambda x=1: x
```

Here's how the code will flow:
* `infer_scope_types` for the global scope
* `infer_lambda_expression`
* `infer_expression` for the default value `1`
* `file_expression_type` for the return type using the body expression.
This is because the body creates it's own scope
* `infer_scope_types` (lambda body scope)
* `infer_name_load` for the symbol `x` whose visible binding is the
lambda parameter `x`
* `infer_parameter_definition` for parameter `x`
* `file_expression_type` for the default value `1`
* `infer_scope_types` for the global scope because of the default
expression

This will then reach to `infer_definition` for the parameter `x` again
which then creates the cycle.

## Test Plan

Add tests around `lambda` expression inference.
2025-03-11 11:25:20 +05:30
David Peter c60e8a037a
[red-knot] Add support for calling `type[…]` (#16597)
## Summary

This fixes the non-diagnostics part of #15948.

## Test Plan

New Markdown tests.

Negative diff on the ecosystem checks:

```diff
zipp (https://github.com/jaraco/zipp)
- error: lint:call-non-callable
-    --> /tmp/mypy_primer/projects/zipp/zipp/__init__.py:393:16
-     |
- 392 |     def _next(self, at):
- 393 |         return self.__class__(self.root, at)
-     |                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Object of type `type[Unknown]` is not callable
- 394 |
- 395 |     def is_dir(self):
-     |
- 
- Found 9 diagnostics
+ Found 8 diagnostics

arrow (https://github.com/arrow-py/arrow)
+     |
+     |
+ warning: lint:unused-ignore-comment
+    --> /tmp/mypy_primer/projects/arrow/arrow/arrow.py:576:66
+ 574 |                 values.append(1)
+ 575 |
+ 576 |             floor = self.__class__(*values, tzinfo=self.tzinfo)  # type: ignore[misc]
+     |                                                                  -------------------- Unused blanket `type: ignore` directive
+ 577 |
+ 578 |             if frame_absolute == "week":
- error: lint:call-non-callable
-     --> /tmp/mypy_primer/projects/arrow/arrow/arrow.py:1080:16
-      |
- 1078 |           dt = self._datetime.astimezone(tz)
- 1079 |
- 1080 |           return self.__class__(
-      |  ________________^
- 1081 | |             dt.year,
- 1082 | |             dt.month,
- 1083 | |             dt.day,
- 1084 | |             dt.hour,
- 1085 | |             dt.minute,
- 1086 | |             dt.second,
- 1087 | |             dt.microsecond,
- 1088 | |             dt.tzinfo,
- 1089 | |             fold=getattr(dt, "fold", 0),
- 1090 | |         )
-      | |_________^ Object of type `type[Unknown]` is not callable
- 1091 |
- 1092 |       # string output and formatting
-      |

black (https://github.com/psf/black)
- 
-     |
-     |
- error: lint:call-non-callable
-    --> /tmp/mypy_primer/projects/black/src/blib2to3/pgen2/grammar.py:135:15
- 133 |         Copy the grammar.
- 134 |         """
- 135 |         new = self.__class__()
-     |               ^^^^^^^^^^^^^^^^ Object of type `type[@Todo]` is not callable
- 136 |         for dict_attr in (
- 137 |             "symbol2number",
- Found 328 diagnostics
+ Found 327 diagnostics
```
2025-03-10 13:24:13 +01:00
Alex Waygood b6c7ba4f8e
[red-knot] Reduce Salsa lookups in `Type::find_name_in_mro` (#16582)
## Summary

Theoretically this should be slightly more performant, since the
`class.is_known()` calls each do a separate Salsa lookup, which we can
avoid if we do a single `match` on the value of `class.known()`. It also
ends up being two lines less code overall!

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-03-10 07:55:22 +01:00
Alex Waygood c970b794d0
Fix broken red-knot property tests (#16574)
## Summary

Fixes #16566, fixes #16575

The semantics of `Type::class_member` changed in
https://github.com/astral-sh/ruff/pull/16416, but the property-test
infrastructure was not updated. That means that the property tests were
panicking on the second `expect_type` call here:


0361021863/crates/red_knot_python_semantic/src/types/property_tests.rs (L151-L158)

With the somewhat unhelpful message:

```
Expected a (possibly unbound) type, not an unbound symbol
```

Applying this patch, and then running `QUICKCHECK_TESTS=1000000 cargo
test --release -p red_knot_python_semantic -- --ignored
types::property_tests::stable::equivalent_to_is_reflexive` showed
clearly that it was no longer able to find _any_ methods on _any_
classes due to the change in semantics of `Type::class_member`:

```diff
--- a/crates/red_knot_python_semantic/src/types/property_tests.rs
+++ b/crates/red_knot_python_semantic/src/types/property_tests.rs
@@ -27,7 +27,7 @@
 use std::sync::{Arc, Mutex, MutexGuard, OnceLock};
 
 use crate::db::tests::{setup_db, TestDb};
-use crate::symbol::{builtins_symbol, known_module_symbol};
+use crate::symbol::{builtins_symbol, known_module_symbol, Symbol};
 use crate::types::{
     BoundMethodType, CallableType, IntersectionBuilder, KnownClass, KnownInstanceType,
     SubclassOfType, TupleType, Type, UnionType,
@@ -150,10 +150,11 @@ impl Ty {
             Ty::BuiltinsFunction(name) => builtins_symbol(db, name).symbol.expect_type(),
             Ty::BuiltinsBoundMethod { class, method } => {
                 let builtins_class = builtins_symbol(db, class).symbol.expect_type();
-                let function = builtins_class
-                    .class_member(db, method.into())
-                    .symbol
-                    .expect_type();
+                let Symbol::Type(function, ..) =
+                    builtins_class.class_member(db, method.into()).symbol
+                else {
+                    panic!("no method `{method}` on class `{class}`");
+                };
 
                 create_bound_method(db, function, builtins_class)
             }
```

This PR updates the property-test infrastructure to use `Type::member`
rather than `Type::class_member`.

## Test Plan

- Ran `QUICKCHECK_TESTS=1000000 cargo test --release -p
red_knot_python_semantic -- --ignored types::property_tests::stable`
successfully
- Checked that there were no remaining uses of `Type::class_member` in
`property_tests.rs`
2025-03-09 17:40:08 +00:00
Alex Waygood 335b264fe2
[red-knot] Consistent spelling of "metaclass" and "meta-type" (#16576)
## Summary

Fixes a small nit of mine -- we are currently inconsistent in our
spelling between "metaclass" and "meta class", and between "meta type"
and "meta-type". This PR means that we consistently use "metaclass" and
"meta-type".

## Test Plan

`uvx pre-commit run -a`
2025-03-09 12:30:32 +00:00
Dhruv Manilawala 0361021863
[red-knot] Understand `typing.Callable` (#16493)
## Summary

Part of https://github.com/astral-sh/ruff/issues/15382

This PR implements a general callable type that wraps around a
`Signature` and it uses that new type to represent `typing.Callable`.

It also implements `Display` support for `Callable`. The format is as:
```
([<arg name>][: <arg type>][ = <default type>], ...) -> <return type>
```

The `/` and `*` separators are added at the correct boundary for
positional-only and keyword-only parameters. Now, as `typing.Callable`
only has positional-only parameters, the rendered signature would be:

```py
Callable[[int, str], None]
# (int, str, /) -> None
```

The `/` separator represents that all the arguments are positional-only.

The relationship methods that check assignability, subtype relationship,
etc. are not yet implemented and will be done so as a follow-up.

## Test Plan

Add test cases for display support for `Signature` and various mdtest
for `typing.Callable`.
2025-03-08 03:58:52 +00:00
Eric Mark Martin 24c8b1242e
[red-knot] Support unpacking `with` target (#16469)
## Summary

Resolves #16365

Add support for unpacking `with` statement targets.

## Test Plan

Added some test cases, alike the ones added by #15058.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-08 02:36:35 +00:00
David Peter 820a31af5d
[red-knot] Attribute access and the descriptor protocol (#16416)
## Summary

* Attributes/method are now properly looked up on metaclasses, when
called on class objects
* We properly distinguish between data descriptors and non-data
descriptors (but we do not yet support them in store-context, i.e.
`obj.data_descr = …`)
* The descriptor protocol is now implemented in a single unified place
for instances, classes and dunder-calls. Unions and possibly-unbound
symbols are supported in all possible stages of the process by creating
union types as results.
* In general, the handling of "possibly-unbound" symbols has been
improved in a lot of places: meta-class attributes, attributes,
descriptors with possibly-unbound `__get__` methods, instance
attributes, …
* We keep track of type qualifiers in a lot more places. I anticipate
that this will be useful if we import e.g. `Final` symbols from other
modules (see relevant change to typing spec:
https://github.com/python/typing/pull/1937).
* Detection and special-casing of the `typing.Protocol` special form in
order to avoid lots of changes in the test suite due to new `@Todo`
types when looking up attributes on builtin types which have `Protocol`
in their MRO. We previously
looked up attributes in a wrong way, which is why this didn't come up
before.

closes #16367
closes #15966

## Context

The way attribute lookup in `Type::member` worked before was simply
wrong (mostly my own fault). The whole instance-attribute lookup should
probably never have been integrated into `Type::member`. And the
`Type::static_member` function that I introduced in my last descriptor
PR was the wrong abstraction. It's kind of fascinating how far this
approach took us, but I am pretty confident that the new approach
proposed here is what we need to model this correctly.

There are three key pieces that are required to implement attribute
lookups:

- **`Type::class_member`**/**`Type::find_in_mro`**: The
`Type::find_in_mro` method that can look up attributes on class bodies
(and corresponding bases). This is a partial function on types, as it
can not be called on instance types like`Type::Instance(…)` or
`Type::IntLiteral(…)`. For this reason, we usually call it through
`Type::class_member`, which is essentially just
`type.to_meta_type().find_in_mro(…)` plus union/intersection handling.
- **`Type::instance_member`**: This new function is basically the
type-level equivalent to `obj.__dict__[name]` when called on
`Type::Instance(…)`. We use this to discover instance attributes such as
those that we see as declarations on class bodies or as (annotated)
assignments to `self.attr` in methods of a class.
- The implementation of the descriptor protocol. It works slightly
different for instances and for class objects, but it can be described
by the general framework:
- Call `type.class_member("attribute")` to look up "attribute" in the
MRO of the meta type of `type`. Call the resulting `Symbol` `meta_attr`
(even if it's unbound).
- Use `meta_attr.class_member("__get__")` to look up `__get__` on the
*meta type* of `meta_attr`. Call it with `__get__(meta_attr, self,
self.to_meta_type())`. If this fails (either the lookup or the call),
just proceed with `meta_attr`. Otherwise, replace `meta_attr` in the
following with the return type of `__get__`. In this step, we also probe
if a `__set__` or `__delete__` method exists and store it in
`meta_attr_kind` (can be either "data descriptor" or "normal attribute
or non-data descriptor").
  - Compute a `fallback` type.
    - For instances, we use `self.instance_member("attribute")`
- For class objects, we use `class_attr =
self.find_in_mro("attribute")`, and then try to invoke the descriptor
protocol on `class_attr`, i.e. we look up `__get__` on the meta type of
`class_attr` and call it with `__get__(class_attr, None, self)`. This
additional invocation of the descriptor protocol on the fallback type is
one major asymmetry in the otherwise universal descriptor protocol
implementation.
- Finally, we look at `meta_attr`, `meta_attr_kind` and `fallback`, and
handle various cases of (possible) unboundness of these symbols.
- If `meta_attr` is bound and a data descriptor, just return `meta_attr`
- If `meta_attr` is not a data descriptor, and `fallback` is bound, just
return `fallback`
- If `meta_attr` is not a data descriptor, and `fallback` is unbound,
return `meta_attr`
- Return unions of these three possibilities for partially-bound
symbols.

This allows us to handle class objects and instances within the same
framework. There is a minor additional detail where for instances, we do
not allow the fallback type (the instance attribute) to completely
shadow the non-data descriptor. We do this because we (currently) don't
want to pretend that we can statically infer that an instance attribute
is always set.

Dunder method calls can also be embedded into this framework. The only
thing that changes is that *there is no fallback type*. If a dunder
method is called on an instance, we do not fall back to instance
variables. If a dunder method is called on a class object, we only look
it up on the meta class, never on the class itself.

## Test Plan

New Markdown tests.
2025-03-07 22:03:28 +01:00
Shunsuke Shibayama 348c196cb3
[red-knot] avoid inferring types if unpacking fails (#16530)
## Summary

This PR closes #15199.

The change I just made is to set all variables to type `Unknown` if
unpacking fails, but in some cases this may be excessive.
For example:

```py
a, b, c = "ab"
reveal_type(a)  # Unknown, but it would be reasonable to think of it as LiteralString
reveal_type(c)  # Unknown
```

```py
# Failed to unpack before the starred expression
(a, b, *c, d, e) = (1,)
reveal_type(a)  # Unknown
reveal_type(b)  # Unknown
...
# Failed to unpack after the starred expression
(a, b, *c, d, e) = (1, 2, 3)
reveal_type(a)  # Unknown, but should it be Literal[1]?
reveal_type(b)  # Unknown, but should it be Literal[2]?
reveal_type(c)  # Todo
reveal_type(d)  # Unknown
reveal_type(e)  # Unknown
```

I will modify it if you think it would be better to make it a different
type than just `Unknown`.

## Test Plan

I have made appropriate modifications to the test cases affected by this
change, and also added some more test cases.
2025-03-07 11:04:44 -08:00
David Peter 0a627ef216
[red-knot] Never is callable and iterable. Arbitrary attributes can be accessed. (#16533)
## Summary

- `Never` is callable
- `Never` is iterable
- Arbitrary attributes can be accessed on `Never`

Split out from #16416 that is going to be required.

## Test Plan

Tests for all properties above.
2025-03-06 15:59:19 +00:00
Micha Reiser ce0018c3cb
Add `OsSystem` support to mdtests (#16518)
## Summary

This PR introduces a new mdtest option `system` that can either be
`in-memory` or `os`
where `in-memory` is the default.

The motivation for supporting `os` is so that we can write OS/system
specific tests
with mdtests. Specifically, I want to write mdtests for the module
resolver,
testing that module resolution is case sensitive. 

## Test Plan

I tested that the case-sensitive module resolver test start failing when
setting `system = "os"`
2025-03-06 10:41:40 +01:00
Micha Reiser 48f906e06c
Add tests for case-sensitive module resolution (#16517)
## Summary

Python's module resolver is case sensitive. 

This PR adds mdtests that assert that our module resolution is case
sensitive.

The tests currently all pass because our in memory file system is case
sensitive.
I'll add support for using the real file system to the mdtest framework
in a separate PR.

This PR also adds support for specifying extra search paths to the
mdtest framework.

## Test Plan
The tests fail when running them using the real file system.
2025-03-06 10:19:23 +01:00
Douglas Creager ebd172e732
[red-knot] Several failing tests for generics (#16509)
To kick off the work of supporting generics, this adds many new
(currently failing) tests, showing the behavior we plan to support.

This is still missing a lot!  Not included:

- typevar tuples
- param specs
- variance
- `Self`

But it's a good start! We can add more failing tests for those once we
tackle these.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-05 17:21:19 -05:00
Carl Meyer 114abc7cfb
[red-knot] support empty TypeInference with fallback type (#16510)
This is split out of https://github.com/astral-sh/ruff/pull/14029, to
reduce the size of that PR, and to validate that this "fallback type"
support in `TypeInference` doesn't come with a performance cost. It also
improves the reliability and debuggability of our current (temporary)
cycle handling.

In order to recover from a cycle, we have to be able to construct a
"default" `TypeInference` where all expressions and definitions have
some "default" type. In our current cycle handling, this "default" type
is just unknown or a todo type. With fixpoint iteration, the "default"
type will be `Type::Never`, which is the "bottom" type that fixpoint
iteration starts from.

Since it would be costly (both in space and time) to actually enumerate
all expressions and definitions in a scope, just to insert the same
default type for all of them, instead we add an optional "missing type"
fallback to `TypeInference`, which (if set) is the fallback type for any
expression or definition which doesn't have an explicit type set.

With this change, cycles can no longer result in the dreaded "Missing
key" errors looking up the type of some expression.
2025-03-05 09:12:27 -08:00
Andrew Gallant 021640a7a6 ruff_db: rename `Diagnostic` to `OldDiagnosticTrait`
This trait should eventually go away, so we rename it (and supporting
types) to make room for a new concrete `Diagnostic` type.

This commit is just the rename. In the next commit, we'll move it to a
different module.
2025-03-05 08:23:02 -05:00
Dhruv Manilawala d94a78a134
[red-knot] De-duplicate symbol table query (#16515)
## Summary

This PR does a small refactor to avoid double
`symbol_table(...).symbol(...)` call to check for `__slots__` and
`TYPE_CHECKING`. It merges them into a single call.

I noticed this while looking at
https://github.com/astral-sh/ruff/pull/16468.
2025-03-05 07:36:21 +00:00
Shunsuke Shibayama bb44926ca5
[red-knot] Add rule `invalid-type-checking-constant` (#16501)
## Summary

This PR adds more features to #16468.

* Adds a new error rule `invalid-type-checking-constant`, which occurs
when we try to assign a value other than `False` to a user-defined
`TYPE_CHECKING` variable (it is possible to assign `...` in a stub
file).
* Allows annotated assignment to `TYPE_CHECKING`. Only types that
`False` can be assigned to are allowed. However, the type of
`TYPE_CHECKING` will be inferred to be `Literal[True]` regardless of
what the type is specified.

## Test plan

I ran the tests with `cargo test -p red_knot_python_semantic` and
confirmed that all tests passed.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-04 19:49:34 +00:00
Shunsuke Shibayama 1977dda079
[red-knot] respect `TYPE_CHECKING` even if not imported from typing (#16468)
## Summary

This PR closes #15722.

The change is that if the variable `TYPE_CHECKING` is defined/imported,
the type of the variable is interpreted as `Literal[True]` regardless of
what the value is.
This is compatible with the behavior of other type checkers (e.g. mypy,
pyright).

## Test Plan

I ran the tests with `cargo test -p red_knot_python_semantic` and
confirmed that all tests passed.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-03-04 07:58:29 -08:00
Douglas Creager ba44e9de13
[red-knot] Don't use separate ID types for each alist (#16415)
Regardless of whether #16408 and #16311 pan out, this part is worth
pulling out as a separate PR.

Before, you had to define a new `IndexVec` index type for each type of
association list you wanted to create. Now there's a single index type
that's internal to the alist implementation, and you use `List<K, V>` to
store a handle to a particular list.

This also adds some property tests for the alist implementation.
2025-02-28 14:55:55 -05:00
Mike Perlov fdf0915283
[red-knot] treat annotated assignments without RHS in stubs as bindings (#16409) 2025-02-28 16:45:21 +00:00
Alex Waygood 09d0b227fb
[red-knot] Disallow more invalid type expressions (#16427) 2025-02-28 10:04:30 +00:00
Carl Meyer fb778ee38d
[red-knot] unify LoopState and saved_break_states (#16406)
We currently keep two separate pieces of state regarding the current
loop on `SemanticIndexBuilder`. One is an enum simply reflecting whether
we are currently inside a loop, and the other is the saved flow states
for `break` statements found in the current loop.

For adding loopy control flow, I'll need to add some additional loop
state (`continue` states, for example). Prepare for this by
consolidating our existing loop state into a single struct and
simplifying the API for pushing and popping a loop.

This is purely a refactor, so tests are not changed.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-02-26 22:31:13 +00:00
Carl Meyer 87d011e1bd
[red-knot] fix non-callable reporting for unions (#16387)
Minor follow-up to https://github.com/astral-sh/ruff/pull/16161

This `not_callable` flag wasn't functional, because it could never be
`false`. It was initialized to `true` and then only ever updated with
`|=`, which can never make it `false`.

Add a test that exercises the case where it _should_ be `false` (all of
the union elements are callable) but `bindings` is also empty (all union
elements have binding errors). Before this PR, the added test wrongly
emits a diagnostic that the union `Literal[f1] | Literal[f2]` is not
callable.

And add a test where a union call results in one binding error and one
not-callable error, where we currently give the wrong result (we show
only the binding error), with a TODO.

Also add TODO comments in a couple other tests where ideally we'd report
more than just one error out of a union call.

Also update the flag name to `all_errors_not_callable` to more clearly
indicate the semantics of the flag.
2025-02-26 07:06:04 -08:00
Douglas Creager b39a4ad01d
[red-knot] Rename constraint to predicate (#16382)
In https://github.com/astral-sh/ruff/pull/16306#discussion_r1966290700,
@carljm pointed out that #16306 introduced a terminology problem, with
too many things called a "constraint". This is a follow-up PR that
renames `Constraint` to `Predicate` to hopefully clear things up a bit.
So now we have that:

- a _predicate_ is a Python expression that might influence type
inference
- a _narrowing constraint_ is a list of predicates that constraint the
type of a binding that is visible at a use
- a _visibility constraint_ is a ternary formula of predicates that
define whether a binding is visible or a statement is reachable

This is a pure renaming, with no behavioral changes.
2025-02-25 14:52:40 -05:00
David Peter 86b01d2d3c
[red-knot] Correct modeling of dunder calls (#16368)
## Summary

Model dunder-calls correctly (and in one single place), by implementing
this behavior (using `__getitem__` as an example).

```py
def getitem_desugared(obj: object, key: object) -> object:
    getitem_callable = find_in_mro(type(obj), "__getitem__")
    if hasattr(getitem_callable, "__get__"):
        getitem_callable = getitem_callable.__get__(obj, type(obj))

    return getitem_callable(key)
```

See the new `calls/dunder.md` test suite for more information. The new
behavior also needs much fewer lines of code (the diff is positive due
to new tests).

## Test Plan

New tests; fix TODOs in existing tests.
2025-02-25 20:38:15 +01:00
David Peter f88328eedd
[red-knot] Handle possibly-unbound instance members (#16363)
## Summary

Adds support for possibly-unbound/undeclared instance members.

## Test Plan

New MD tests.
2025-02-25 20:00:38 +01:00
Douglas Creager fa76f6cbb2
[red-knot] Use arena-allocated association lists for narrowing constraints (#16306)
This PR adds an implementation of [association
lists](https://en.wikipedia.org/wiki/Association_list), and uses them to
replace the previous `BitSet`/`SmallVec` representation for narrowing
constraints.

An association list is a linked list of key/value pairs. We additionally
guarantee that the elements of an association list are sorted (by their
keys), and that they do not contain any entries with duplicate keys.

Association lists have fallen out of favor in recent decades, since you
often need operations that are inefficient on them. In particular,
looking up a random element by index is O(n), just like a linked list;
and looking up an element by key is also O(n), since you must do a
linear scan of the list to find the matching element. Luckily we don't
need either of those operations for narrowing constraints!

The typical implementation also suffers from poor cache locality and
high memory allocation overhead, since individual list cells are
typically allocated separately from the heap. We solve that last problem
by storing the cells of an association list in an `IndexVec` arena.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-02-25 10:58:56 -05:00
Alex Waygood 5c007db7e2
[red-knot] Rewrite `Type::try_iterate()` to improve type inference and diagnostic messages (#16321) 2025-02-25 14:02:03 +00:00
David Peter aac79e453a
[red-knot] Better diagnostics for method calls (#16362)
## Summary

Add better error messages and additional spans for method calls. Can be
reviewed commit-by-commit.

before:

```
error: lint:invalid-argument-type
 --> /home/shark/playground/test.py:6:10
  |
5 | c = C()
6 | c.square("hello")  # error: [invalid-argument-type]
  |          ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 2 (`x`); expected type `int`
7 |
8 | # import inspect
  |
```

after:

```
error: lint:invalid-argument-type
 --> /home/shark/playground/test.py:6:10
  |
5 | c = C()
6 | c.square("hello")  # error: [invalid-argument-type]
  |          ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 2 (`x`) of bound method `square`; expected type `int`
7 |
8 | # import inspect
  |
 ::: /home/shark/playground/test.py:2:22
  |
1 | class C:
2 |     def square(self, x: int) -> int:
  |                      ------ info: parameter declared in function definition here
3 |         return x * x
  |
```

## Test Plan

New snapshot test
2025-02-25 09:58:08 +01:00
Micha Reiser 4732c58829
Rename `venv-path` to `python` (#16347) 2025-02-24 19:41:06 +01:00
Alex Waygood 45bae29a4b
[red-knot] Fixup some formatting in `infer.rs` (#16348) 2025-02-24 14:44:49 +00:00
Alex Waygood 7059f4249b
[red-knot] Restrict visibility of more things in `class.rs` (#16346) 2025-02-24 14:30:56 +00:00
Mike Perlov 68991d09a8
[red-knot] Add diagnostic for class-object access to pure instance variables (#16036)
## Summary

Add a diagnostic if a pure instance variable is accessed on a class object. For example

```py
class C:
    instance_only: str

    def __init__(self):
        self.instance_only = "a"

# error: Attribute `instance_only` can only be accessed on instances, not on the class object `Literal[C]` itself.
C.instance_only
```


---------

Co-authored-by: David Peter <mail@david-peter.de>
2025-02-24 15:17:16 +01:00
Alex Waygood 5bac4f6bd4
[red-knot] Add a test to ensure that `KnownClass::try_from_file_and_name()` is kept up to date (#16326) 2025-02-24 12:14:20 +00:00
Micha Reiser 320a3c68ae
Extract class and instance types (#16337) 2025-02-24 11:36:20 +00:00
David Peter 141ba253da
[red-knot] Add support for `@classmethod`s (#16305)
## Summary

Add support for `@classmethod`s.

```py
class C:
    @classmethod
    def f(cls, x: int) -> str:
        return "a"

reveal_type(C.f(1))  # revealed: str
```

## Test Plan

New Markdown tests
2025-02-24 09:55:34 +01:00
Micha Reiser 5eaf225fc3
Update Salsa part 1 (#16340) 2025-02-24 09:35:21 +01:00
Alex Waygood 64effa4aea
[red-knot] Add a regression test for recent improvement to `TypeInferenceBuilder::infer_name_load()` (#16310) 2025-02-21 22:28:42 +00:00
Alex Waygood 224a36f5f3
Teach red-knot that `type(x)` is the same as `x.__class__` (#16301) 2025-02-21 21:05:48 +00:00
Alex Waygood 5347abc766
[red-knot] Generalise special-casing for `KnownClass`es in `Type::bool` (#16300) 2025-02-21 20:46:36 +00:00
Micha Reiser 5fab97f1ef
[red-knot] Diagnostics for incorrect `bool` usages (#16238) 2025-02-21 19:26:05 +01:00
David Peter 3aa7ba31b1
[red-knot] Fix descriptor `__get__` call on class objects (#16304)
## Summary

I spotted a minor mistake in my descriptor protocol implementation where
`C.descriptor` would pass the meta type (`type`) of the type of `C`
(`Literal[C]`) as the owner argument to `__get__`, instead of passing
`Literal[C]` directly.

## Test Plan

New test.
2025-02-21 15:35:41 +01:00
Douglas Creager 4dae09ecff
[red-knot] Better handling of visibility constraint copies (#16276)
Two related changes.  For context:

1. We were maintaining two separate arenas of `Constraint`s in each
use-def map. One was used for narrowing constraints, and the other for
visibility constraints. The visibility constraint arena was interned,
ensuring that we always used the same ID for any particular
`Constraint`. The narrowing constraint arena was not interned.

2. The TDD code relies on _all_ TDD nodes being interned and reduced.
This is an important requirement for TDDs to be a canonical form, which
allows us to use a single int comparison to test for "always true/false"
and to compare two TDDs for equivalence. But we also need to support an
individual `Constraint` having multiple values in a TDD evaluation (e.g.
to handle a `while` condition having different values the first time
it's evaluated vs later times). Previously, we handled that by
introducing a "copy" number, which was only there as a disambiguator, to
allow an interned, deduplicated constraint ID to appear in the TDD
formula multiple times.

A better way to handle (2) is to not intern the constraints in the
visibility constraint arena! The caller now gets to decide: if they add
a `Constraint` to the arena more than once, they get distinct
`ScopedConstraintId`s — which the TDD code will treat as distinct
variables, allowing them to take on different values in the ternary
function.

With that in place, we can then consolidate on a single (non-interned)
arena, which is shared for both narrowing and visibility constraints.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-02-21 09:16:25 -05:00
Alex Waygood b3c5932fda
[red-knot] Restrict visibility of the `module_type_symbols` function (#16290) 2025-02-21 10:55:22 +00:00
Alex Waygood fe3ae587ea
[red-knot] Fix subtle detail in where the `types.ModuleType` attribute lookup should happen in `TypeInferenceBuilder::infer_name_load()` (#16284) 2025-02-21 10:48:52 +00:00
David Peter d2e034adcd
[red-knot] Method calls and the descriptor protocol (#16121)
## Summary

This PR achieves the following:

* Add support for checking method calls, and inferring return types from
method calls. For example:
  ```py
  reveal_type("abcde".find("abc"))  # revealed: int
  reveal_type("foo".encode(encoding="utf-8"))  # revealed: bytes
  
  "abcde".find(123)  # error: [invalid-argument-type]
  
  class C:
      def f(self) -> int:
          pass
  
  reveal_type(C.f)  # revealed: <function `f`>
  reveal_type(C().f)  # revealed: <bound method: `f` of `C`>
  
  C.f()  # error: [missing-argument]
  reveal_type(C().f())  # revealed: int
  ```
* Implement the descriptor protocol, i.e. properly call the `__get__`
method when a descriptor object is accessed through a class object or an
instance of a class. For example:
  ```py
  from typing import Literal
  
  class Ten:
def __get__(self, instance: object, owner: type | None = None) ->
Literal[10]:
          return 10
  
  class C:
      ten: Ten = Ten()
  
  reveal_type(C.ten)  # revealed: Literal[10]
  reveal_type(C().ten)  # revealed: Literal[10]
  ```
* Add support for member lookup on intersection types.
* Support type inference for `inspect.getattr_static(obj, attr)` calls.
This was mostly used as a debugging tool during development, but seems
more generally useful. It can be used to bypass the descriptor protocol.
For the example above:
  ```py
  from inspect import getattr_static
  
  reveal_type(getattr_static(C, "ten"))  # revealed: Ten
  ```
* Add a new `Type::Callable(…)` variant with the following sub-variants:
* `Type::Callable(CallableType::BoundMethod(…))` — represents bound
method objects, e.g. `C().f` above
* `Type::Callable(CallableType::MethodWrapperDunderGet(…))` — represents
`f.__get__` where `f` is a function
* `Type::Callable(WrapperDescriptorDunderGet)` — represents
`FunctionType.__get__`
* Add new known classes:
  * `types.MethodType`
  * `types.MethodWrapperType`
  * `types.WrapperDescriptorType`
  * `builtins.range`

## Performance analysis

On this branch, we do more work. We need to do more call checking, since
we now check all method calls. We also need to do ~twice as many member
lookups, because we need to check if a `__get__` attribute exists on
accessed members.

A brief analysis on `tomllib` shows that we now call `Type::call` 1780
times, compared to 612 calls before.

## Limitations

* Data descriptors are not yet supported, i.e. we do not infer correct
types for descriptor attribute accesses in `Store` context and do not
check writes to descriptor attributes. I felt like this was something
that could be split out as a follow-up without risking a major
architectural change.
* We currently distinguish between `Type::member` (with descriptor
protocol) and `Type::static_member` (without descriptor protocol). The
former corresponds to `obj.attr`, the latter corresponds to
`getattr_static(obj, "attr")`. However, to model some details correctly,
we would also need to distinguish between a static member lookup *with*
and *without* instance variables. The lookup without instance variables
corresponds to `find_name_in_mro`
[here](https://docs.python.org/3/howto/descriptor.html#invocation-from-an-instance).
We currently approximate both using `member_static`, which leads to two
open TODOs. Changing this would be a larger refactoring of
`Type::own_instance_member`, so I chose to leave it out of this PR.

## Test Plan

* New `call/methods.md` test suite for method calls
* New tests in `descriptor_protocol.md`
* New `call/getattr_static.md` test suite for `inspect.getattr_static`
* Various updated tests
2025-02-20 23:22:26 +01:00
David Peter f62e5406f2
[red-knot] Short-circuit bool calls on bool (#16292)
## Summary

This avoids looking up `__bool__` on class `bool` for every
`Type::Instance(bool).bool()` call. 1% performance win on cold cache, 4%
win on incremental performance.
2025-02-20 23:06:11 +01:00
Douglas Creager 1be4394155
[red-knot] Consolidate `SymbolBindings`/`SymbolDeclarations` state (#16286)
This updates the `SymbolBindings` and `SymbolDeclarations` types to use
a single smallvec of live bindings/declarations, instead of splitting
that out into separate containers for each field.

I'm seeing an 11-13% `cargo bench` performance improvement with this
locally (for both cold and incremental). I'm interested to see if
Codspeed agrees!

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-02-20 16:20:23 -05:00
Micha Reiser 470f852f04
[red-knot] Prevent cross-module query dependencies in `own_instance_member` (#16268) 2025-02-20 18:46:45 +01:00
Douglas Creager 529950fba1
[red-knot] Separate `definitions_by_definition` into separate fields (#16277)
A minor cleanup that breaks up a `HashMap` of an enum into separate
`HashMap`s for each variant. (These separate fields were already how
this cache was being described in the big comment at the top of the
file!)
2025-02-20 09:47:01 -05:00
Andrew Gallant 205222ca6b red_knot_python_semantic: avoid adding `callable_ty` to `CallBindingError`
This is a small tweak to avoid adding the callable `Type` on the error
value itself. Namely, it's always available regardless of the error, and
it's easy to pass it down explicitly to the diagnostic generating code.

It's likely that the other `CallBindingError` variants will also want
the callable `Type` to improve diagnostics too. This way, we don't have
to duplicate the `Type` on each variant. It's just available to all of
them.

Ref https://github.com/astral-sh/ruff/pull/16239#discussion_r1962352646
2025-02-20 08:18:59 -05:00
David Peter 8198668fc3
[red-knot] MDTest: Use custom class names instead of builtins (#16269)
## Summary

Follow up on the discussion
[here](https://github.com/astral-sh/ruff/pull/16121#discussion_r1962973298).
Replace builtin classes with custom placeholder names, which should
hopefully make the tests a bit easier to understand.

I carefully renamed things one after the other, to make sure that there
is no functional change in the tests.
2025-02-20 12:25:55 +00:00
Micha Reiser fb09d63e55
[red-knot] Prefix `Type::call` and `dunder_call` with `try` (#16261) 2025-02-20 09:05:04 +00:00
Alex Waygood 25920fe489
Rename `ExprStringLiteral::as_unconcatenated_string()` to `ExprStringLiteral::as_single_part_string()` (#16253) 2025-02-19 16:06:57 +00:00
Douglas Creager cfc6941d5c
[red-knot] Resolve references in eager nested scopes eagerly (#16079)
We now resolve references in "eager" scopes correctly — using the
bindings and declarations that are visible at the point where the eager
scope is created, not the "public" type of the symbol (typically the
bindings visible at the end of the scope).

---------

Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-02-19 10:22:30 -05:00
Micha Reiser 55ea09401a
[red-knot] Allow any `Ranged` argument for `report_lint` and `report_diagnostic` (#16252) 2025-02-19 14:34:56 +01:00
Andrew Gallant 3ea32e2cdd red_knot_python_semantic: improve diagnostic message for "invalid argument type"
This uses the refactoring and support for secondary diagnostic messages
to improve the diagnostic for "invalid argument type." The main
improvement here is that we show where the function being called is
defined, and annotate the span corresponding to the invalid parameter.
2025-02-19 08:24:19 -05:00
Andrew Gallant 87668e24b1 ruff_db: add "secondary" messages to `Diagnostic` trait
This is a small little hack to make the `Diagnostic` trait
capable of supporting attaching multiple spans.

This design should be considered transient. This was just the
quickest way that I could see to pass multiple spans through from
the type checker to the diagnostic renderer.
2025-02-19 08:24:19 -05:00
Andrew Gallant 222660170c red_knot_python_semantic: remove `Ranged` impl for `TypeCheckDiagnostic`
It seems nothing is using it, and I'm not sure if it makes semantic
sense. Particularly if we want to support multiple ranges. One could
make an argument that this ought to correspond to the "primary"
range (which we should have), but I think such a concept is better
expressed as an explicit routine if possible.
2025-02-19 08:24:19 -05:00
Micha Reiser e84985e9b3
[red-knot] Refactor `infer_chained_boolean_types` to have access to `TypeInferenceBuilder` (#16222) 2025-02-19 11:13:35 +01:00
David Peter 877c1066d3
[red-knot] Update tests for attributes inferred from parameters (#16208)
## Summary

Update description and remove TODOs from out `attributes.md` test suite
to reflect our current intentions.

closes https://github.com/astral-sh/ruff/issues/15960
2025-02-18 22:43:11 +01:00
Carl Meyer 00b022d472
[red-knot] update TODO comment in mdtest (#16242)
This comment gave wrong/misleading info about the reason for the wrong
output, just updating it to be correct to avoid confusing our future
selves.
2025-02-18 20:52:17 +00:00
Brent Westbrook a9efdea113
Use `ast::PythonVersion` internally in the formatter and linter (#16170)
## Summary

This PR updates the formatter and linter to use the `PythonVersion`
struct from the `ruff_python_ast` crate internally. While this doesn't
remove the need for the `linter::PythonVersion` enum, it does remove the
`formatter::PythonVersion` enum and limits the use in the linter to
deserializing from CLI arguments and config files and moves most of the
remaining methods to the `ast::PythonVersion` struct.

## Test Plan

Existing tests, with some inputs and outputs updated to reflect the new
(de)serialization format. I think these are test-specific and shouldn't
affect any external (de)serialization.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-02-18 12:03:13 -05:00
Micha Reiser 4ed5db0d42
Refactor `CallOutcome` to `Result` (#16161) 2025-02-18 13:34:39 +01:00
Dhruv Manilawala 9f111eaebf
red-knot: move symbol lookups in `symbol.rs` (#16152)
## Summary

This PR does the following:
* Moves the following from `types.rs` in `symbol.rs`:
	* `symbol`
	* `global_symbol`
	* `imported_symbol`
	* `symbol_from_bindings`
	* `symbol_from_declarations`
	* `SymbolAndQualifiers`
	* `SymbolFromDeclarationsResult`
* Moves the following from `stdlib.rs` in `symbol.rs` and removes
`stdlib.rs`:
	* `known_module_symbol`
	* `builtins_symbol`
	* `typing_symbol` (only for tests)
	* `typing_extensions_symbol`
	* `builtins_module_scope`
	* `core_module_scope`
* Add `symbol_from_bindings_impl` and `symbol_from_declarations_impl` to
keep `RequiresExplicitReExport` an implementation detail
* Make `declaration_type` a `pub(crate)` as it's required in
`symbol_from_declarations` (`binding_type` is already `pub(crate)`

The main motivation is to keep the implementation details private and
only expose an ergonomic API which uses sane defaults for various
scenario to avoid any mistakes from the caller. Refer to
https://github.com/astral-sh/ruff/pull/16133#discussion_r1955262772,
https://github.com/astral-sh/ruff/pull/16133#issue-2850146612 for
details.
2025-02-17 17:45:38 +05:30
Alex Waygood b6b1947010
Improve API exposed on `ExprStringLiteral` nodes (#16192)
## Summary

This PR makes the following changes:
- It adjusts various callsites to use the new
`ast::StringLiteral::contents_range()` method that was introduced in
https://github.com/astral-sh/ruff/pull/16183. This is less verbose and
more type-safe than using the `ast::str::raw_contents()` helper
function.
- It adds a new `ast::ExprStringLiteral::as_unconcatenated_literal()`
helper method, and adjusts various callsites to use it. This addresses
@MichaReiser's review comment at
https://github.com/astral-sh/ruff/pull/16183#discussion_r1957334365.
There is no functional change here, but it helps readability to make it
clearer that we're differentiating between implicitly concatenated
strings and unconcatenated strings at various points.
- It renames the `StringLiteralValue::flags()` method to
`StringLiteralFlags::first_literal_flags()`. If you're dealing with an
implicitly concatenated string `string_node`,
`string_node.value.flags().closer_len()` could give an incorrect result;
this renaming makes it clearer that the `StringLiteralFlags` instance
returned by the method is only guaranteed to give accurate information
for the first `StringLiteral` contained in the `ExprStringLiteral` node.
- It deletes the unused `BytesLiteralValue::flags()` method. This seems
prone to misuse in the same way as `StringLiteralValue::flags()`: if
it's an implicitly concatenated bytestring, the `BytesLiteralFlags`
instance returned by the method would only give accurate information for
the first `BytesLiteral` in the bytestring.

## Test Plan

`cargo test`
2025-02-17 07:58:54 +00:00
Alex Waygood 4941975e74
[red-knot] Recognize `...` as a singleton (#16184) 2025-02-16 22:01:02 +00:00
Alex Waygood 93aff36147
[red-knot] Improve handling of inherited class attributes (#16160) 2025-02-15 18:22:35 +00:00
Micha Reiser b3e99b25bf
Fix missing serde feature for red_knot_python_semantic (#16169)
## Summary

Running `cargo test -p red_knot_python_semantic` failed because of a
missing serde feature. This PR enables the `ruff_python_ast`'`s `serde`
if the crate's `serde` feature is enabled

## Test Plan

`cargo test -p red_knot_python_semantic` compiles again
2025-02-14 20:31:55 +00:00
Carl Meyer dcabb948f3
[red-knot] add special case for float/complex (#16166)
When adjusting the existing tests, I aimed to avoid dealing with the
special case in other tests if it's not necessary to do so (that is,
avoid using `float` and `complex` as examples where we just need "some
type"), and keep the tests for the special case mostly collected in the
mdtest dedicated to that purpose.

Fixes https://github.com/astral-sh/ruff/issues/14932
2025-02-14 12:24:10 -08:00
Brent Westbrook f58a54f043
Move `red_knot_python_semantic::PythonVersion` to the `ruff_python_ast` crate (#16147)
## Summary

This PR moves the `PythonVersion` struct from the
`red_knot_python_semantic` crate to the `ruff_python_ast` crate so that
it can be used more easily in the syntax error detection work. Compared
to that [prototype](https://github.com/astral-sh/ruff/pull/16090/) these
changes reduce us from 2 `PythonVersion` structs to 1.

This does not unify any of the `PythonVersion` *enums*, but I hope to
make some progress on that in a follow-up.

## Test Plan

Existing tests, this should not change any external behavior.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-02-14 12:48:08 -05:00
Dhruv Manilawala 63dd68e0ed
Refactor symbol lookup APIs to hide re-export implementation details (#16133)
## Summary

This PR refactors the symbol lookup APIs to better facilitate the
re-export implementation. Specifically,
* Add `module_type_symbol` which returns the `Symbol` that's a member of
`types.ModuleType`
* Rename `symbol` -> `symbol_impl`; add `symbol` which delegates to
`symbol_impl` with `RequireExplicitReExport::No`
* Update `global_symbol` to do `symbol_impl` -> fall back to
`module_type_symbol` and default to `RequireExplicitReExport::No`
* Add `imported_symbol` to do `symbol_impl` with
`RequireExplicitReExport` as `Yes` if the module is in a stub file else
`No`
* Update `known_module_symbol` to use `imported_symbol` with a fallback
to `module_type_symbol`
* Update `ModuleLiteralType::member` to use `imported_symbol` with a
custom fallback

We could potentially also update `symbol_from_declarations` and
`symbol_from_bindings` to avoid passing in the `RequireExplicitReExport`
as it would be always `No` if called directly. We could add
`symbol_from_declarations_impl` and `symbol_from_bindings_impl`.

Looking at the `_impl` functions, I think we should move all of these
symbol related logic into `symbol.rs` where `Symbol` is defined and the
`_impl` could be private while we expose the public APIs at the crate
level. This would also make the `RequireExplicitReExport` an
implementation detail and the caller doesn't need to worry about it.
2025-02-14 15:25:48 +05:30
Dhruv Manilawala 60b3ef2c98
[red-knot] Support re-export conventions for stub files (#16073)
This is an alternative implementation to #15848.

## Summary

This PR adds support for re-export conventions for imports for stub
files.

**How does this work?**
* Add a new flag on the `Import` and `ImportFrom` definitions to
indicate whether they're being exported or not
* Add a new enum to indicate whether the symbol lookup is happening
within the same file or is being queried from another file (e.g., an
import statement)
* When a `Symbol` is being queried, we'll skip the definitions that are
(a) coming from a stub file (b) external lookup and (c) check the
re-export flag on the definition

This implementation does not yet support `__all__` and `*` imports as
both are features that needs to be implemented independently.

closes: #14099
closes: #15476 

## Test Plan

Add test cases, update existing ones if required.
2025-02-14 15:17:51 +05:30
Micha Reiser 81e202ed52
Make `CallBinding::callable_ty` required (#16135)
## Summary

The `callable_ty` is always known except in some TODO code where we can
use a `TODO` type instead.

## Test Plan

`cargo test`
2025-02-14 08:15:24 +01:00
Alex Waygood be49151a3d
[red-knot] Remove a parameter from the `symbol_by_id()` query (#16138) 2025-02-13 13:33:40 +00:00
David Peter 366ae1feaa
[red-knot] Document 'public type of undeclared symbols' behavior (#16096)
## Summary

After I was asked twice within the same day, I thought it would be a
good idea to write some *user facing* documentation that explains our
reasoning behind inferring `Unknown | T_inferred` for public uses of
undeclared symbols. This is a major deviation from the behavior of other
type checkers and it seems like a good practice to defend our choice
like this.
2025-02-12 08:52:11 +01:00
Andrew Gallant 6e34f74c16
add diagnostic `Span` (couples `File` and `TextRange`) (#16101)
This essentially makes it impossible to construct a `Diagnostic`
that has a `TextRange` but no `File`.

This is meant to be a precursor to multi-span support.

(Note that I consider this more of a prototyping-change and not
necessarily what this is going to look like longer term.)

Reviewers can probably review this PR as one big diff instead of
commit-by-commit.
2025-02-11 14:55:12 -05:00
Micha Reiser 9c179314ed
Remove `Hash` and `Eq` from `AstNodeRef` for types not implementing `Eq` or `Hash` (#16100)
## Summary

This is a follow up to
https://github.com/astral-sh/ruff/pull/15763#discussion_r1949681336

It reverts the change to using ptr equality for `AstNodeRef`s, which in
turn removes the `Eq`, `PartialEq`, and `Hash` implementations for
`AstNodeRef`s parametrized with AST nodes.
Cheap comparisons shouldn't be needed because the node field is
generally marked as `[#tracked]` and `#[no_eq]` and removing the
implementations even enforces that those
attributes are set on all `AstNodeRef` fields (which is good).

The only downside this has is that we technically wouldn't have to mark
the `Unpack::target` as `#[tracked]` because
the `target` field is accessed in every query accepting `Unpack` as an
argument.

Overall, enforcing the use of `#[tracked]` seems like a good trade off,
espacially considering that it's very likely that
we'd probably forget to mark the `Unpack::target` field as tracked if we
add a new `Unpack` query that doesn't access the target.

## Test Plan

`cargo test`
2025-02-11 19:55:50 +01:00
Micha Reiser ce31c2693b
Fix release build warning about unused todo type message (#16102) 2025-02-11 18:38:41 +00:00
Alex Waygood df1d430294
[red-knot] Reduce usage of `From<Type>` implementations when working with `Symbol`s (#16076) 2025-02-11 11:09:37 +00:00
Ibraheem Ahmed 69d86d1d69
Transition to salsa coarse-grained tracked structs (#15763)
## Summary

Transition to using coarse-grained tracked structs (depends on
https://github.com/salsa-rs/salsa/pull/657). For now, this PR doesn't
add any `#[tracked]` fields, meaning that any changes cause the entire
struct to be invalidated. It also changes `AstNodeRef` to be
compared/hashed by pointer address, instead of performing a deep AST
comparison.

## Test Plan

This yields a 10-15% improvement on my machine (though weirdly some runs
were 5-10% without being flagged as inconsistent by criterion, is there
some non-determinism involved?). It's possible that some of this is
unrelated, I'll try applying the patch to the current salsa version to
make sure.

---------

Co-authored-by: Micha Reiser <micha@reiser.io>
2025-02-11 11:38:50 +01:00
David Peter 0019d39f6e
[red-knot] `T | object == object` (#16088)
## Summary

- Simplify unions with `object` to `object`.
- Add a new `Type::object(db)` constructor to abbreviate
`KnownClass::Object.to_instance(db)` in some places.
- Add a `Type::is_object` and `Class::is_object` function to make some
tests for a bit easier to read.

closes #16084

## Test Plan

New Markdown tests.
2025-02-10 23:07:06 +01:00
Micha Reiser af832560fc
[red-knot] User-level configuration (#16021)
## Summary

This PR adds support for user-level configurations
(`~/.config/knot/knot.toml`) to Red Knot.

Red Knot will watch the user-level configuration file for changes but
only if it exists
when the process start. It doesn't watch for new configurations, 
mainly to simplify things for now (it would require watching the entire
`.config` directory because the `knot` subfolder might not exist
either).

The new `ConfigurationFile` struct seems a bit overkill for now but I
plan to use it for
hierarchical configurations as well. 


Red Knot uses the same strategy as uv and Ruff by using the etcetera
crate.

## Test Plan

Added CLI and file watching test
2025-02-10 16:44:23 +01:00
Micha Reiser f7819e553f
Add `user_configuration_directory` to `System` (#16020)
## Summary

This PR adds a new `user_configuration_directory` method to `System`. We
need it to resolve where to lookup a user-level `knot.toml`
configuration file.
The method belongs to `System` because not all platforms have a
convention of where to store such configuration files (e.g. wasm).


I refactored `TestSystem` to be a simple wrapper around an `Arc<dyn
System...>` and use the `System.as_any` method instead to cast it down
to an `InMemory` system. I also removed some `System` specific methods
from `InMemoryFileSystem`, they don't belong there.

This PR removes the `os` feature as a default feature from `ruff_db`.
Most crates depending on `ruff_db` don't need it because they only
depend on `System` or only depend on `os` for testing. This was
necessary to fix a compile error with `red_knot_wasm`

## Test Plan

I'll make use of the method in my next PR. So I guess we won't know if
it works before then but I copied the code from Ruff/uv, so I have high
confidence that it is correct.

`cargo test`
2025-02-10 15:50:55 +01:00
Micha Reiser 678b0c2d39
[red-knot] Resolve `Options` to `Settings` (#16000)
## Summary

This PR generalize the idea that we may want to emit diagnostics for 
invalid or incompatible configuration values similar to how we already 
do it for `rules`. 

This PR introduces a new `Settings` struct that is similar to `Options`
but, unlike
`Options`, are fields have their default values filled in and they use a
representation optimized for reads.

The diagnostics created during loading the `Settings` are stored on the
`Project` so that we can emit them when calling `check`.

The motivation for this work is that it simplifies adding new settings.
That's also why I went ahead and added the `terminal.error-on-warning`
setting to demonstrate how new settings are added.

## Test Plan

Existing tests, new CLI test.
2025-02-10 15:28:45 +01:00
Alex Waygood fc59e1b17f
[red-knot] Merge `TypeInferenceBuilder::infer_name_load` and `TypeInferenceBuilder::lookup_name` (#16019)
## Summary

No functional change here; this is another simplification split out from
my outcome-refactor branch to reduce the diff there. This merges
`TypeInferenceBuilder::infer_name_load` and
`TypeInferenceBuilder::lookup_name`. This removes the need to have
extensive doc-comments about the purpose of
`TypeInferenceBuilder::lookup_name`, since the method only makes sense
when called from the specific context of
`TypeInferenceBuilder::infer_name_load`.

## Test Plan

`cargo test -p red_knot_python_semantic`
2025-02-08 19:42:14 +00:00
David Peter 1f7a29d347
[red-knot] Unpacker: Make invariant explicit and directly return a Type (#16018)
## Summary

- Do not return `Option<Type<…>>` from `Unpacker::get`, but just `Type`.
Panic otherwise.
- Rename `Unpacker::get` to `Unpacker::expression_type`
2025-02-07 12:00:04 +00:00
David Peter 97e6fc3793
[red-knot] Unpacking and for loop assignments to attributes (#16004)
## Summary

* Support assignments to attributes in more cases:
    - assignments in `for` loops
    - in unpacking assignments
* Add test for multi-target assignments
* Add tests for all other possible assignments to attributes that could
   possibly occur (in decreasing order of likeliness):
    - augmented attribute assignments
    - attribute assignments in `with` statements
    - attribute assignments in comprehensions
- Note: assignments to attributes in named expressions are not
   syntactically allowed

closes #15962

## Test Plan

New Markdown tests
2025-02-07 11:30:51 +01:00
Micha Reiser 38351e00ee
[red-knot] Partial revert of relative import handling for files in the root of a search path (#16001)
## Summary

This PR reverts the behavior changes from
https://github.com/astral-sh/ruff/pull/15990

But it isn't just a revert, it also:

* Adds a test covering this specific behavior
* Preserves the improvement to use `saturating_sub` in the package case
to avoid overflows in the case of invalid syntax
* Use `ancestors` instead of a `for` loop

## Test Plan

Added test
2025-02-07 11:04:09 +01:00
Micha Reiser 26c37b1e0e
Add knot.toml schema (#15735)
## Summary

Adds a JSON schema generation step for Red Knot. This PR doesn't yet add
a publishing step because it's still a bit early for that


## Test plan

I tested the schema in Zed, VS Code and PyCharm:

* PyCharm: You have to manually add a schema mapping (settings JSON
Schema Mappings)
* Zed and VS code support the inline schema specification

```toml
#:schema /Users/micha/astral/ruff/knot.schema.json


[environment]
extra-paths = []


[rules]
call-possibly-unbound-method = "error"
unknown-rule = "error"

# duplicate-base = "error"
```

```json
{
    "$schema": "file:///Users/micha/astral/ruff/knot.schema.json",

    "environment": {
        "python-version": "3.13",
        "python-platform": "linux2"
    },

    "rules": {
        "unknown-rule": "error"
    }
}
```


https://github.com/user-attachments/assets/a18fcd96-7cbe-4110-985b-9f1935584411


The Schema overall works but all editors have their own quirks:

* PyCharm: Hovering a name always shows the section description instead
of the description of the specific setting. But it's the same for other
settings in `pyproject.toml` files 🤷
* VS Code (JSON): Using the generated schema in a JSON file gives
exactly the experience I want
* VS Code (TOML): 
* Properties with multiple possible values are repeated during
auto-completion without giving any hint how they're different. ![Screen
Shot 2025-02-06 at 14 05 35
PM](https://github.com/user-attachments/assets/d7f3c2a9-2351-4226-9fc1-b91aa192a237)
* The property description mushes together the description of the
property and the value, which looks sort of ridiculous. ![Screen Shot
2025-02-06 at 14 04 40
PM](https://github.com/user-attachments/assets/8b72f04a-c62a-49b5-810f-7ddd472884d0)
* Autocompletion and documentation hovering works (except the
limitations mentioned above)
* Zed:
* Very similar to VS Code with the exception that it uses the
description attribute to distinguish settings with multiple possible
values ![Screen Shot 2025-02-06 at 14 08 19
PM](https://github.com/user-attachments/assets/78a7f849-ff4e-44ff-8317-708eaf02dc1f)


I don't think there's much we can do here other than hope (or help)
editors improve their auto completion. The same short comings also apply
to ruff, so this isn't something new. For now, I think this is good
enough
2025-02-07 10:59:40 +01:00
David Peter e345307260
[red-knot] Fix diagnostic range for non-iterable unpacking assignments (#15994)
## Summary

I noticed that the diagnostic range in specific unpacking assignments is
wrong. For this example

```py
a, b = 1
```

we previously got (see first commit):

```
error: lint:not-iterable
 --> /src/mdtest_snippet.py:1:1
  |
1 | a, b = 1
  | ^^^^ Object of type `Literal[1]` is not iterable
  |
```

and with this change, we get:

```
error: lint:not-iterable
 --> /src/mdtest_snippet.py:1:8
  |
1 | a, b = 1
  |        ^ Object of type `Literal[1]` is not iterable
  |
```

## Test Plan

New snapshot tests.
2025-02-06 15:36:22 +01:00
Micha Reiser 5588c75d65
[red-knot] Fix relative imports in `src.root` (#15990)
## Summary

Fixes https://github.com/astral-sh/ruff/issues/15989

Red Knot failed to resolve relative imports if the importing module is
located at a search path root.

The issue was that the module resolver returned an `Err(TooManyDots)` as
soon as the parent of the current module is `None` (which is the case
for a module at the search path root).
However, this is incorrect if a `tail` (a module name) exists.
2025-02-06 14:08:20 +00:00
David Peter d0555f7b5c
[red-knot] Litate tests: minor follow-up (#15987)
## Summary

- Minor wording update
- Code improvement (thanks Alex)
- Removed all unnecessary filenames throughout our Markdown tests (two
new ones were added in the meantime)
- Minor rewording of the statically-known-branches introduction
2025-02-06 07:15:26 +00:00
Douglas Creager 0906554357
[red-knot] Combine terminal statement support with statically known branches (#15817)
This example from @sharkdp shows how terminal statements can appear in
statically known branches:
https://github.com/astral-sh/ruff/pull/15676#issuecomment-2618809716

```py
def _(cond: bool):
    x = "a"
    if cond:
        x = "b"
        if True:
            return

    reveal_type(x)  # revealed: "a", "b"; should be "a"
```

We now use visibility constraints to track reachability, which allows us
to model this correctly. There are two related changes as a result:

- New bindings are not assumed to be visible; they inherit the current
"scope start" visibility, which effectively means that new bindings are
visible if/when the current flow is reachable

- When simplifying visibility constraints after branching control flow,
we only simplify if none of the intervening branches included a terminal
statement. That is, earlier unaffected bindings are only _actually_
unaffected if all branches make it to the merge point.
2025-02-05 17:47:49 -05:00
David Peter d296f602e7
[red-knot] Merge Markdown code blocks inside a single section (#15950)
## Summary

Allow for literate style in Markdown tests and merge multiple (unnamed)
code blocks into a single embedded file.

closes #15941

## Test Plan

- Interactively made sure that error-lines were reported correctly in
  multi-snippet sections.
2025-02-05 22:26:15 +01:00
Andrew Gallant d47088c8f8
[red-knot] fix unresolvable import range (#15976)
This causes the diagnostic to highlight the actual unresovable import
instead of the entire `from ... import ...` statement.

While we're here, we expand the test coverage to cover all of the
possible ways that an `import` or a `from ... import` can fail.

Some considerations:

* The first commit in this PR adds a regression test for the current
behavior.
* This creates a new `mdtest/diagnostics` directory. Are folks cool
with this? I guess the idea is to put tests more devoted to diagnostics
than semantics in this directory. (Although I'm guessing there will
be some overlap.)

Fixes #15866
2025-02-05 14:01:58 -05:00
David Peter 1f0ad675d3
[red-knot] Initial set of descriptor protocol tests (#15972)
## Summary

This is a first step towards creating a test suite for
[descriptors](https://docs.python.org/3/howto/descriptor.html). It does
not (yet) aim to be exhaustive.

relevant ticket: #15966 

## Test Plan

Compared desired behavior with the runtime behavior and the behavior of
existing type checkers.

---------

Co-authored-by: Mike Perlov <mishamsk@gmail.com>
2025-02-05 19:47:43 +01:00
Andrew Gallant a84b27e679 red_knot_test: add support for diagnostic snapshotting
This ties together everything from the previous commits.
Some interesting bits here are how the snapshot is generated
(where we include relevant info to make it easier to review
the snapshots) and also a tweak to how inline assertions are
processed.

This commit also includes some example snapshots just to get
a sense of what they look like. Follow-up work should add
more of these I think.
2025-02-05 13:02:54 -05:00
Andrew Gallant b40a7cce15 red_knot_test: add snapshot path
This makes it possible for callers to set where snapshots
should be stored. In general, I think we expect this to
always be set, since otherwise snapshots will end up in
`red_knot_test`, which is where the tests are actually run.
But that's overall counter-intuitive. This permits us to
store snapshots from mdtests alongside the mdtests themselves.
2025-02-05 13:02:54 -05:00
Alex Waygood c816542704
[red-knot] Fix some instance-attribute TODOs around `ModuleType` (#15974) 2025-02-05 15:33:37 +00:00
Alex Waygood 2ebb5e8d4b
[red-knot] Make `Symbol::or_fall_back_to()` lazy (#15943) 2025-02-05 14:51:02 +00:00
David Peter eb08345fd5
[red-knot] Extend instance/class attribute tests (#15959)
## Summary

In preparation for creating some (sub) issues for
https://github.com/astral-sh/ruff/issues/14164, I'm trying to document
the current behavior (and a bug) a bit better.
2025-02-05 12:45:00 +01:00
Mike Perlov e15419396c
[red-knot] Fix Stack overflow in Type::bool (#15843)
## Summary

This PR adds `Type::call_bound` method for calls that should follow
descriptor protocol calling convention. The PR is intentionally shallow
in scope and only fixes #15672

Couple of obvious things that weren't done:

* Switch to `call_bound` everywhere it should be used
* Address the fact, that red_knot resolves `__bool__ = bool` as a Union,
which includes `Type::Dynamic` and hence fails to infer that the
truthiness is always false for such a class (I've added a todo comment
in mdtests)
* Doesn't try to invent a new type for descriptors, although I have a
gut feeling it may be more convenient in the end, instead of doing
method lookup each time like I did in `call_bound`

## Test Plan

* extended mdtests with 2 examples from the issue
* cargo neatest run
2025-02-04 12:40:07 -08:00
Douglas Creager 444b055cec
[red-knot] Use ternary decision diagrams (TDDs) for visibility constraints (#15861)
We now use ternary decision diagrams (TDDs) to represent visibility
constraints. A TDD is just like a BDD ([_binary_ decision
diagram](https://en.wikipedia.org/wiki/Binary_decision_diagram)), but
with "ambiguous" as an additional allowed value. Unlike the previous
representation, TDDs are strongly normalizing, so equivalent ternary
formulas are represented by exactly the same graph node, and can be
compared for equality in constant time.

We currently have a slight 1-3% performance regression with this in
place, according to local testing. However, we also have a _5× increase_
in performance for pathological cases, since we can now remove the
recursion limit when we evaluate visibility constraints.

As follow-on work, we are now closer to being able to remove the
`simplify_visibility_constraint` calls in the semantic index builder. In
the vast majority of cases, we now see (for instance) that the
visibility constraint after an `if` statement, for bindings of symbols
that weren't rebound in any branch, simplifies back to `true`. But there
are still some cases we generate constraints that are cyclic. With
fixed-point cycle support in salsa, or with some careful analysis of the
still-failing cases, we might be able to remove those.
2025-02-04 14:32:11 -05:00
David Peter 24c1cf71cb
[red-knot] Use unambiguous invalid-syntax-construct for suppression comment test (#15933)
## Summary

I experimented with [not trimming trailing newlines in code
snippets](https://github.com/astral-sh/ruff/pull/15926#discussion_r1940992090),
but since came to the conclusion that the current behavior is better
because otherwise, there is no way to write snippets without a trailing
newline at all. And when you copy the code from a Markdown snippet in
GitHub, you also don't get a trailing newline.

I was surprised to see some test failures when I played with this
though, and decided to make this test independent from this
implementation detail.
2025-02-04 15:24:50 +01:00
Brent Westbrook b5e5271adf
Preserve triple quotes and prefixes for strings (#15818)
## Summary

This is a follow-up to #15726, #15778, and #15794 to preserve the triple
quote and prefix flags in plain strings, bytestrings, and f-strings.

I also added a `StringLiteralFlags::without_triple_quotes` method to
avoid passing along triple quotes in rules like SIM905 where it might
not make sense, as discussed
[here](https://github.com/astral-sh/ruff/pull/15726#discussion_r1930532426).

## Test Plan

Existing tests, plus many new cases in the `generator::tests::quote`
test that should cover all combinations of quotes and prefixes, at least
for simple string bodies.

Closes #7799 when combined with #15694, #15726, #15778, and #15794.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-02-04 08:41:06 -05:00
InSync 11cfe2ea8a
[red-knot] Enforce specifying paths for mdtest code blocks in a separate preceding line (#15890)
## Summary

Resolves #15695, rework of #15704.

This change modifies the Mdtests framework so that:

* Paths must now be specified in a separate preceding line:

	`````markdown
	`a.py`:

	```py
	x = 1
	```
	`````

If the path of a file conflicts with its `lang`, an error will be
thrown.

* Configs are no longer accepted. The pattern still take them into
account, however, to avoid "Unterminated code block" errors.
* Unnamed files are now assigned unique, `lang`-respecting paths
automatically.

Additionally, all legacy usages have been updated.

## Test Plan

Unit tests and Markdown tests.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-02-04 08:27:17 +01:00
Douglas Creager 0529ad67d7
[red-knot] Internal refactoring of visibility constraints API (#15913)
This extracts some pure refactoring noise from
https://github.com/astral-sh/ruff/pull/15861. This changes the API for
creating and evaluating visibility constraints, but does not change how
they are respresented internally. There should be no behavioral or
performance changes in this PR.

Changes:

- Hide the internal representation isn't changed, so that we can make
changes to it in #15861.
- Add a separate builder type for visibility constraints. (With TDDs, we
will have some additional builder state that we can throw away once
we're done constructing.)
- Remove a layer of helper methods from `UseDefMapBuilder`, making
`SemanticIndexBuilder` responsible for constructing whatever visibility
constraints it needs.
2025-02-03 15:13:09 -05:00
David Peter 102c2eec12
[red-knot] Implicit instance attributes (#15811)
## Summary

Add support for implicitly-defined instance attributes, i.e. support
type inference for cases like this:
```py
class C:
    def __init__(self) -> None:
        self.x: int = 1
        self.y = None

reveal_type(C().x)  # int
reveal_type(C().y)  # Unknown | None
```

## Benchmarks

Codspeed reports no change in a cold-cache benchmark, and a -1%
regression in the incremental benchmark. On `black`'s `src` folder, I
don't see a statistically significant difference between the branches:

| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `./red_knot_main check --project /home/shark/black/src` | 133.7 ± 9.5 | 126.7 | 164.7 | 1.01 ± 0.08 |
| `./red_knot_feature check --project /home/shark/black/src` | 132.2 ± 5.1 | 118.1 | 140.9 | 1.00 |

## Test Plan

Updated and new Markdown tests
2025-02-03 19:34:23 +01:00
Dhruv Manilawala d082c1b202
[red-knot] Add missing imports in mdtests (#15869)
## Summary

Related to #15848, this PR adds the imports explicitly as we'll now flag
these symbols as undefined.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-02-03 09:27:29 +00:00
Alex Waygood d9a1034db0
Add convenience helper methods for AST nodes representing function parameters (#15871) 2025-02-01 17:16:32 +00:00
Douglas Creager fab86de3ef
[red-knot] Should A ∧ !A always be false? (#15839)
This mimics a simplification we have on the OR side, where we simplify
`A ∨ !A` to true. This requires changes to how we add `while` statements
to the semantic index, since we now need distinct
`VisibilityConstraint`s if we need to model evaluating a `Constraint`
multiple times at different points in the execution of the program.
2025-01-31 14:06:52 -05:00
Carl Meyer ce769f6ae2
[red-knot] gather type prevalence statistics (#15834)
Something Alex and I threw together during our 1:1 this morning. Allows
us to collect statistics on the prevalence of various types in a file,
most usefully TODO types or other dynamic types.
2025-01-31 07:10:00 -08:00
David Peter 451f251a31
[red-knot] Clarify behavior when redeclaring base class attributes (#15826)
# Summary

Clarify the behavior regarding re-declaration of attributes from base
classes following [this
discussion](https://github.com/astral-sh/ruff/pull/15808#discussion_r1934236095)
2025-01-30 14:49:23 +01:00
Alex Waygood 3125332ec1
[red-knot] Format mdtest snippets with the latest version of black (#15819) 2025-01-29 23:05:43 +00:00
Douglas Creager 15d886a502
[red-knot] Consider all definitions after terminal statements unreachable (#15676)
`FlowSnapshot` now tracks a `reachable` bool, which indicates whether we
have encountered a terminal statement on that control flow path. When
merging flow states together, we skip any that have been marked
unreachable. This ensures that bindings that can only be reached through
unreachable paths are not considered visible.

## Test Plan

The new mdtests failed (with incorrect `reveal_type` results, and
spurious `possibly-unresolved-reference` errors) before adding the new
visibility constraints.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-01-29 14:06:57 -05:00
David Peter 0f1035b930
[red-knot] Extend instance-attribute tests (#15808)
## Summary

When we discussed the plan on how to proceed with instance attributes,
we said that we should first extend our research into the behavior of
existing type checkers. The result of this research is summarized in the
newly added / modified tests in this PR. The TODO comments align with
existing behavior of other type checkers. If we deviate from the
behavior, it is described in a comment.
2025-01-29 14:06:32 +01:00
David Peter ca53eefa6f
[red-knot] Do not use explicit `knot_extensions.Unknown` declaration (#15787)
## Summary

Do not use an explict `knot_extensions.Unknown` declaration, as per
[this
comment](https://github.com/astral-sh/ruff/pull/15766#discussion_r1930997592).
Instead, use an undefined name to achieve the same effect.
2025-01-28 17:18:22 +01:00
David Peter 2ef94e5f3e
[red-knot] Document public symbol type inferece (#15766)
## Summary

Adds a slightly more comprehensive documentation of our behavior
regarding type inference for public uses of symbols. In particular:

- What public type do we infer for `x: int = any()`?
- What public type do we infer for `x: Unknown = 1`?
2025-01-27 10:52:13 +01:00
Alex Waygood c824140fa8
[red-knot] Ensure differently ordered unions are considered equivalent when they appear inside tuples inside top-level intersections (#15743) 2025-01-25 18:19:28 +00:00
Alex Waygood f85ea1bf46
[red-knot] Ensure differently ordered unions and intersections are understood as equivalent even inside arbitrarily nested tuples (#15740)
## Summary

On `main`, red-knot:
- Considers `P | Q` equivalent to `Q | P`
- Considered `tuple[P | Q]` equivalent to `tuple[Q | P]`
- Considers `tuple[P | tuple[P | Q]]` equivalent to `tuple[tuple[Q | P]
| P]`
- ‼️ Does _not_ consider `tuple[tuple[P | Q]]` equivalent to
`tuple[tuple[Q | P]]`

The key difference for the last one of these is that the union appears
inside a tuple that is directly nested inside another tuple.

This PR fixes this so that differently ordered unions are considered
equivalent even when they appear inside arbitrarily nested tuple types.

## Test Plan

- Added mdtests that fails on `main`
- Checked that all property tests continue to pass with this PR
2025-01-25 16:39:07 +00:00
Alex Waygood a77a32b7d4
[red-knot] Promote the `all_type_pairs_are_assignable_to_their_union` property test to stable (#15739) 2025-01-25 16:26:37 +00:00
Douglas Creager 5a9d71a5f1
Speed symbol state merging back up (#15731)
This is a follow-up to #15702 that hopefully claws back the 1%
performance regression. Assuming it works, the trick is to iterate over
the constraints vectors via mut reference (aka a single pointer), so
that we're not copying `BitSet`s into and out of the zip tuples as we
iterate. We use `std::mem::take` as a poor-man's move constructor only
at the very end, when we're ready to emplace it into the result. (C++
idioms intended! 😄)

With local testing via hyperfine, I'm seeing this be 1-3% faster than
`main` most of the time — though a small number of runs (1 in 10,
maybe?) are a wash or have `main` faster. Codspeed reports a 2%
gain.
2025-01-24 16:07:31 -05:00
Douglas Creager 716b246cf3
[red-knot] Use itertools to clean up `SymbolState::merge` (#15702)
[`merge_join_by`](https://docs.rs/itertools/latest/itertools/trait.Itertools.html#method.merge_join_by)
handles the "merge two sorted iterators" bit, and `zip` handles
iterating through the bindings/definitions along with their associated
constraints.

---------

Co-authored-by: Micha Reiser <micha@reiser.io>
2025-01-24 10:21:29 -05:00
Micha Reiser 4e3982cf95
[red-knot] Add `--ignore`, `--warn`, and `--error` CLI arguments (#15689) 2025-01-24 16:20:15 +01:00
David Peter 1feb3cf41a
[red-knot] Use `Unknown | T_inferred` for undeclared public symbols (#15674)
## Summary

Use `Unknown | T_inferred` as the type for *undeclared* public symbols.

## Test Plan

- Updated existing tests
- New test for external `__slots__` modifications.
- New tests for external modifications of public symbols.
2025-01-24 12:47:48 +01:00
David Peter fb58a9b610
[red-knot] Rename `TestDbBuilder::typeshed` to `.custom_typeshed` (#15712)
## Summary

Correcting a small oversight by me
(https://github.com/astral-sh/ruff/pull/15683#discussion_r1926830914).
2025-01-24 10:25:23 +00:00
David Peter 15394a8028
[red-knot] MDTests: Do not depend on precise public-symbol type inference (#15691)
## Summary

Another small PR to focus #15674 solely on the relevant changes. This
makes our Markdown tests less dependent on precise types of public
symbols, without actually changing anything semantically in these tests.

Best reviewed using ignore-whitespace-mode.

## Test Plan

Tested these changes on `main` and on the branch from #15674.
2025-01-23 13:51:33 +00:00
David Peter fc2ebea736
[red-knot] Make `infer.rs` unit tests independent of public symbol inference (#15690)
## Summary

Make the remaining `infer.rs` unit tests independent from public symbol
type inference decisions (see upcoming change in #15674).

## Test Plan

- Made sure that the unit tests actually fail if one of the
  `assert_type` assertions is changed.
2025-01-23 14:30:18 +01:00
David Peter 0173738eef
[red-knot] Port comprehension tests to Markdown (#15688)
## Summary

Port comprehension tests from Rust to Markdown

I don' think the remaining tests in `infer.rs` should be ported to
Markdown, maybe except for the incremental-checking tests when (if ever)
we have support for that in the MD tests.


closes #13696
2025-01-23 12:49:30 +00:00
Micha Reiser 05ea77b1d4
Create Unknown rule diagnostics with a source range (#15648) 2025-01-23 12:50:43 +01:00
David Peter 1e790d3885
[red-knot] Port 'deferred annotations' unit tests to Markdown (#15686)
## Summary

- Port "deferred annotations" unit tests to Markdown
- Port `implicit_global_in_function` unit test to Markdown
- Removed `resolve_method` and `local_inference` unit tests. These seem
  like relics from a time where type inference was in it's early stages.
  There is no way that these tests would fail today without lots of other
  things going wrong as well.

part of #13696
based on #15683 

## Test Plan

New MD tests for existing Rust unit tests.
2025-01-23 11:45:05 +00:00
David Peter 7855f03735
[red-knot] Support custom typeshed Markdown tests (#15683)
## Summary

- Add feature to specify a custom typeshed from within Markdown-based
  tests
- Port "builtins" unit tests from `infer.rs` to Markdown tests, part of
  #13696

## Test Plan

- Tests for the custom typeshed feature
- New Markdown tests for deleted Rust unit tests
2025-01-23 12:36:38 +01:00
Micha Reiser 7b17c9c445
Add `rules` table to configuration (#15645) 2025-01-23 10:56:58 +01:00
Micha Reiser 23c222368e
[red-knot] Make `Diagnostic::file` optional (#15640) 2025-01-23 10:43:14 +01:00
David Peter 1ecd97855e
[red-knot] Add test for nested attribute access (#15684)
## Summary

Add a new test for attribute accesses in case of nested modules /
classes. Resolves this comment:

https://github.com/astral-sh/ruff/pull/15613#discussion_r1925637561

## Test Plan

New MD test.
2025-01-23 10:26:34 +01:00
Alex Waygood b4877f1661
[red-knot] Ensure a gradual type can always be assigned to itself (#15675) 2025-01-22 16:01:13 +00:00
David Peter 3235cd8019
[red-knot] Fix possible TOCTOU mistake in mdtest runner (#15673)
## Summary

Somehow, I managed to crash the `mdtest` runner today. I struggled to
reproduce this again to see if it's actually fixed (even with an
artificial `sleep` between the two `cargo test` invocations), but the
original backtrace clearly showed that this is where the problem
originated from. And it seems like a clear TOCTOU problem.
2025-01-22 15:24:25 +00:00
David Peter 13e7afca42
[red-knot] Improved error message for attribute-assignments (#15668)
## Summary

Slightly improved error message for attribute assignments.
2025-01-22 11:04:38 +00:00
David Peter f349dab4fc
[red-knot] Invalid assignments to attributes (#15613)
## Summary

Raise "invalid-assignment" diagnostics for incorrect assignments to
attributes, for example:

```py
class C:
    var: str = "a"

C.var = 1  # error: "Object of type `Literal[1]` is not assignable to `str`"
```

closes #15456 

## Test Plan

- Updated test assertions
- New test for assignments to module-attributes
2025-01-22 10:42:47 +01:00
David Peter 792f9e357e
[red-knot] Rename *_ty functions (#15617)
## Summary

General rules:

* Change the `_ty` suffix of all functions to `_type`.
* `_type_and_qualifiers` suffixes seem too long, so we ignore the
existence of qualifiers and still speak of "types"
* Functions only have a `_type` suffix if they return either `Type`,
`Option<Type>`, or `TypeAndQualifiers`

Free functions:

* `binding_ty` => `binding_type`
* `declaration_ty` => `declaration_type`
* `definition_expression_ty` => `definition_expression_type`

Methods:

* `CallDunderResult::return_ty` => `return_type`
* `NotCallableError::return_ty` => `return_type`
* `NotCallableError::called_ty` => `called_type`
* `TypeAndQualifiers::inner_ty` => `inner_type`
* `TypeAliasType::value_ty` => `value_type`
* `TypeInference::expression_ty` => `expression_type`
* `TypeInference::try_expression_ty` => `try_expression_type`
* `TypeInference::binding_ty` => `binding_type`
* `TypeInference::declaration_ty` => `declaration_type` 
* `TypeInferenceBuilder::expression_ty` => `expression_type`
* `TypeInferenceBuilder::file_expression_ty` => `file_expression_type`
* `TypeInferenceBuilder::module_ty_from_name` => `module_type_from_name`
* `ClassBase::try_from_ty` => `try_from_type`
* `Parameter::annotated_ty` => `annotated_type`
* `Parameter::default_ty` => `default_type`
* `CallOutcome::return_ty` => `return_type`
* `CallOutcome::return_ty_result` => `return_type_result`
* `CallBinding::from_return_ty` => `from_return_type`
* `CallBinding::set_return_ty` => `set_return_type`
* `CallBinding::return_ty` => `return_type`
* `CallBinding::parameter_tys` => `parameter_types`
* `CallBinding::one_parameter_ty` => `one_parameter_type`
* `CallBinding::two_parameter_tys` => `two_parameter_types`
* `Unpacker::tuple_ty_elements` => `tuple_type_elements`
* `StringPartsCollector::ty` => `string_type`

Traits

* `HasTy` => `HasType`
* `HasTy::ty` => `inferred_type`

Test functions:

* `assert_public_ty` => `assert_public_type`
* `assert_scope_ty` => `assert_scope_type`

closes #15569

## Test Plan

—
2025-01-22 09:06:56 +01:00
Alex Waygood fbb06fe0ac
[red-knot] Small simplifications to `Type::is_subtype_of` and `Type::is_disjoint_from` (#15622)
## Summary

This PR generalizes some of the logic we have in `Type::is_subtype_of`
and `Type::is_disjoint_from` so that we fallback to the instance type of
the metaclass more often in `Type::ClassLiteral` and `Type::SubclassOf`
branches. This simplifies the code (we end up with one less branch in
`is_subtype_of`, and we can remove a helper method that's no longer
used), makes the code more robust (any fixes made to subtyping or
disjointness of instance types will automatically improve our
understanding of subtyping/disjointness for class-literal types and
`type[]` types) and more elegantly expresses the type-system invariants
encoded in these branches.

## Test Plan

No new tests added (it's a pure refactor, adding no new functionality).
All existing tests pass, however, including the property tests.
2025-01-22 00:31:55 +00:00
Douglas Creager ef85c682bd
Remove customizable reference enum names (#15647)
The AST generator creates a reference enum for each syntax group — an
enum where each variant contains a reference to the relevant syntax
node. Previously you could customize the name of the reference enum for
a group — primarily because there was an existing `ExpressionRef` type
that wouldn't have lined up with the auto-derived name `ExprRef`. This
follow-up PR is a simple search/replace to switch over to the
auto-derived name, so that we can remove this customization point.
2025-01-21 13:46:31 -05:00
David Peter 13a6b5600b
[red-knot] mdtest runner: include stderr for crashing tests (#15644)
## Summary

Test executables usually write failure messages (including panics) to
stdout, but I just managed to make a mdtest crash with
```
thread 'mdtest__unary_not' has overflowed its stack
fatal runtime error: stack overflow
```
which is printed to stderr. This test simply appends stderr to stdout
(`stderr=subprocess.STDOUT` can not be used with `capture_output`)

## Test Plan

Make sure that the error message is now visible in the output of `uv -q
run crates/red_knot_python_semantic/mdtest.py`
2025-01-21 14:59:36 +00:00
Micha Reiser 067c6de465
Change `EnvironmentOptions::venv-path` to `Option<SystemPathBuf>` (#15631)
## Summary

The `Options` struct is intended to capture the user's configuration
options but
`EnvironmentOptions::venv_path` supports both a `SitePackages::Known`
and `SitePackages::Derived`.

Users should only be able to provide `SitePackages::Derived`—they
specify a path to a venv, and Red Knot derives the path to the
site-packages directory. We'll only use the `Known` variant once we
automatically discover the Python installation.

That's why this PR changes `EnvironmentOptions::venv_path` from
`Option<SitePackages>` to `Option<SystemPathBuf>`.

This requires making some changes to the file watcher test, and I
decided to use `extra_paths` over venv path
because our venv validation is annoyingly correct -- making mocking a
venv rather involved.

## Test Plan

`cargo test`
2025-01-21 14:10:41 +00:00
David Peter 4656e3c90f
[red-knot] Markdown test runner (#15632)
## Summary

As more and more tests move to Markdown, running the mdtest suite
becomes one of the most common tasks for developers working on Red Knot.
There are a few pain points when doing so, however:

- The `build.rs` script enforces recompilation (~five seconds) whenever
something changes in the `resource/mdtest` folder. This is strictly
necessary, because whenever files are added or removed, the test harness
needs to be updated. But this is very rarely the case! The most common
scenario is that a Markdown file has *changed*, and in this case, no
recompilation is necessary. It is currently not possible to distinguish
these two cases using `cargo::rerun-if-changed`. One can work around
this by running the test executable manually, but it requires finding
the path to the correct `mdtest-<random-hash>` executable.
- All Markdown tests are run by default. This is needed whenever Rust
code changes, but while working on the tests themselves, it is often
much more convenient to only run the tests for a single file. This can
be done by using a `mdtest__path_to_file` filter, but this needs to be
manually spelled out or copied from the test output.
- `cargo`s test output for a failing Markdown test is often
unnecessarily verbose. Unless there is an *actual* panic somewhere in
the code, mdtests usually fail with the explicit *"Some tests failed"*
panic in the mdtest suite. But in those cases, we are not interested in
the pointer to the source of this panic, but only in the mdtest suite
output.

This PR adds a Markdown test runner tool that attempts to make the
developer experience better.

Once it is started using
```bash
uv run -q crates/red_knot_python_semantic/mdtest.py
```
it will first recompile the tests once (if cargo requires it), find the
path to the `mdtest` executable, and then enter into a mode where it
watches for changes in the `red_knot_python_semantic` crate. Whenever …
* … a Markdown file changes, it will rerun the mdtest for this specific
  file automatically (no recompilation!).
* … a Markdown file is added, it will recompile the tests and then run
  the mdtest for the new file
* … Rust code is changed, it will recompile the tests and run all of
  them

The tool also trims down `cargo test` output and only shows the actual
mdtest errors.

The tool will certainly require a few more iterations before it becomes
mature, but I'm curious to hear if there is any interest for something
like this.

## Test Plan

- Tested the new runner under various scenarios.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-01-21 14:06:35 +01:00
Alex Waygood 187a358d7a
[red-knot] Heterogeneous tuple types with differently ordered (but equivalent) unions at the same index should be considered equivalent (#15637) 2025-01-21 12:51:20 +00:00
David Peter 134fefa945
[red-knot] Rename `bindings_ty`, `declarations_ty` (#15618)
## Summary

Rename two functions with outdated names (they used to return `Type`s):

* `bindings_ty` => `symbol_from_bindings` (returns `Symbol`)
* `declarations_ty` => `symbol_from_declarations` (returns a
`SymbolAndQualifiers` result)

I chose `symbol_from_*` instead of `*_symbol` as I found the previous
name quite confusing. Especially since `binding_ty` and `declaration_ty`
also exist (singular).

## Test Plan

—

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2025-01-20 15:23:33 +01:00
wooly18 f82ef32e53
[`red-knot`] No `cyclic-class-def` diagnostics for subclasses of cyclic classes (#15561)
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
2025-01-20 13:35:29 +00:00
David Peter 912247635d
[red-knot] Move `Ty` enum to property tests (#15608)
## Summary

Move the `Ty` enum into the `property_tests` module, as it was only used
in a single place in `types.rs`.
2025-01-20 10:15:31 +01:00