## Summary
With this PR, we emit a diagnostic for this case where
previously didn't:
```py
from typing import Literal
def f(m: int, n: Literal[-1, 0, 1]):
# error: [division-by-zero] "Cannot divide object of type `int` by zero"
return m / n
```
## Test Plan
New Markdown test
I put this in its own commit in case all of the information removed here
was controversial. But it *looks* stale to me. At the very least,
`TypeCheckDiagnostic` no longer exists, so that would need to be fixed.
And it doesn't really make sense to me (at this point) to make
`Diagnostic` a Salsa struct, particularly since we are keen on using it
in Ruff (at some point).
We do keep around `OldSecondaryDiagnosticMessage`, since that's part of
the Red Knot `InferContext` API. But it's a rather simple type, and
we'll be able to delete it entirely once `InferContext` exposes the new
`Diagnostic` type directly.
Since we aren't consuming `OldSecondaryDiagnosticMessage` any more, we
can now accept a slice instead of a vec. (Thanks Clippy.)
This replaces things like `TypeCheckDiagnostic` with the new Diagnostic`
type.
This is a "surgical" replacement where we retain the existing API of
of diagnostic reporting such that _most_ of Red Knot doesn't need to be
changed to support this update. But it will enable us to start using the
new diagnostic renderer and to delete the old renderer. It also paves
the path for exposing the new `Diagnostic` data model to the broader Red
Knot codebase.
I did this mostly because it wasn't buying us much, and I'm
trying to simplify the public API of the types I'd like to
refactor in order to make the refactor simpler.
If we really want something like this, we can re-add it
later.
I removed this to see how much code was depending internally on the
`&[Arc<TypeCheckDiagnostic>]` representation. Thankfully, it was just
one place. So I just removed the `Deref` impl in favor of adding an
explicit `iter` method.
In general, I think using `Deref` for things like this is _somewhat_ of
an abuse. The tip-off is if there are `&self` or `&mut self` methods on
the type, then it's probably not a good candidate for `Deref`.
## Summary
Implement basic *Goto type definition* support for Red Knot's LSP.
This PR also builds the foundation for other LSP operations. E.g., Goto
definition, hover, etc., should be able to reuse some, if not most,
logic introduced in this PR.
The basic steps of resolving the type definitions are:
1. Find the closest token for the cursor offset. This is a bit more
subtle than I first anticipated because the cursor could be positioned
right between the callee and the `(` in `call(test)`, in which case we
want to resolve the type for `call`.
2. Find the node with the minimal range that fully encloses the token
found in 1. I somewhat suspect that 1 and 2 could be done at the same
time but it complicated things because we also need to compute the spine
(ancestor chain) for the node and there's no guarantee that the found
nodes have the same ancestors
3. Reduce the node found in 2. to a node that is a valid goto target.
This may require traversing upwards to e.g. find the closest expression.
4. Resolve the type for the goto target
5. Resolve the location for the type, return it to the LSP
## Design decisions
The current implementation navigates to the inferred type. I think this
is what we want because it means that it correctly accounts for
narrowing (in which case we want to go to the narrowed type because
that's the value's type at the given position). However, it does have
the downside that Goto type definition doesn't work whenever we infer `T
& Unknown` because intersection types aren't supported. I'm not sure
what to do about this specific case, other than maybe ignoring `Unkown`
in Goto type definition if the type is an intersection?
## Known limitations
* Types defined in the vendored typeshed aren't supported because the
client can't open files from the red knot binary (we can either
implement our own file protocol and handler OR extract the typeshed
files and point there). See
https://github.com/astral-sh/ruff/issues/17041
* Red Knot only exposes an API to get types for expressions and
definitions. However, there are many other nodes with identifiers that
can have a type (e.g. go to type of a globals statement, match patterns,
...). We can add support for those in separate PRs (after we figure out
how to query the types from the semantic model). See
https://github.com/astral-sh/ruff/issues/17113
* We should have a higher-level API for the LSP that doesn't directly
call semantic queries. I intentionally decided not to design that API
just yet.
## Test plan
https://github.com/user-attachments/assets/fa077297-a42d-4ec8-b71f-90c0802b4edb
Goto type definition on a union
<img width="1215" alt="Screenshot 2025-04-01 at 13 02 55"
src="https://github.com/user-attachments/assets/689cabcc-4a86-4a18-b14a-c56f56868085"
/>
Note: I recorded this using a custom typeshed path so that navigating to
builtins works.
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## Summary
from https://github.com/astral-sh/ruff/pull/17034#discussion_r2024222525
This is a simple PR to fix the invalid behavior of `NotImplemented` on
Python >=3.10.
## Test Plan
I think it would be better if we could run mdtest across multiple Python
versions in GitHub Actions.
<!-- How was it tested? -->
---------
Co-authored-by: David Peter <sharkdp@users.noreply.github.com>
## Summary
Add support for decorators on function as well as support
for properties by adding special handling for `@property` and `@<name of
property>.setter`/`.getter` decorators.
closes https://github.com/astral-sh/ruff/issues/16987
## Ecosystem results
- ✔️ A lot of false positives are fixed by our new
understanding of properties
- 🔴 A bunch of new false positives (typically
`possibly-unbound-attribute` or `invalid-argument-type`) occur because
we currently do not perform type narrowing on attributes. And with the
new understanding of properties, this becomes even more relevant. In
many cases, the narrowing occurs through an assertion, so this is also
something that we need to implement to get rid of these false positives.
- 🔴 A few new false positives occur because we do not
understand generics, and therefore some calls to custom setters fail.
- 🔴 Similarly, some false positives occur because we do not
understand protocols yet.
- ✔️ Seems like a true positive to me. [The
setter](e624d8edfa/src/packaging/specifiers.py (L752-L754))
only accepts `bools`, but `None` is assigned in [this
line](e624d8edfa/tests/test_specifiers.py (L688)).
```
+ error[lint:invalid-assignment]
/tmp/mypy_primer/projects/packaging/tests/test_specifiers.py:688:9:
Invalid assignment to data descriptor attribute `prereleases` on type
`SpecifierSet` with custom `__set__` method
```
- ✔️ This is arguable also a true positive. The setter
[here](0c6c75644f/rich/table.py (L359-L363))
returns `Table`, but typeshed wants [setters to return
`None`](bf8d2a9912/stdlib/builtins.pyi (L1298)).
```
+ error[lint:invalid-argument-type]
/tmp/mypy_primer/projects/rich/rich/table.py:359:5: Object of type
`Literal[padding]` cannot be assigned to parameter 2 (`fset`) of bound
method `setter`; expected type `(Any, Any, /) -> None`
```
## Follow ups
- Fix the `@no_type_check` regression
- Implement class decorators
## Test Plan
New Markdown test suites for decorators and properties.
## Summary
Part of #15382, this PR adds property tests for callable types.
Specifically, this PR updates the property tests to generate an
arbitrary signature for a general callable type which includes:
* Arbitrary combination of parameter kinds in the correct order
* Arbitrary number of parameters
* Arbitrary optional types for annotation and return type
* Arbitrary parameter names (no duplicate names), optional for
positional-only parameters
## Test Plan
```
QUICKCHECK_TESTS=100000 cargo test -p red_knot_python_semantic -- --ignored types::property_tests::stable
```
Also, the commands in CI:
d72b4100a3/.github/workflows/daily_property_tests.yaml (L47-L52)
## Summary
Part of #15382, this PR adds support for disjointness between two
callable types. They are never disjoint because there exists a callable
type that's a subtype of all other callable types:
```py
(*args: object, **kwargs: object) -> Never
```
The `Never` is a subtype of every fully static type thus a callable type
that has the return type of `Never` means that it is a subtype of every
return type.
## Test Plan
Add test cases related to mixed parameter kinds, gradual form (`...`)
and `Never` type.
## Summary
Currently our `Type::Callable` wraps a four-variant `CallableType` enum.
But as time has gone on, I think we've found that the four variants in
`CallableType` are really more different to each other than they are
similar to each other:
- `GeneralCallableType` is a structural type describing all callable
types with a certain signature, but the other three types are "literal
types", more similar to the `FunctionLiteral` variant
- `GeneralCallableType` is not a singleton or a single-valued type, but
the other three are all single-valued types
(`WrapperDescriptorDunderGet` is even a singleton type)
- `GeneralCallableType` has (or should have) ambiguous truthiness, but
all possible inhabitants of the other three types are always truthy.
- As a structural type, `GeneralCallableType` can contain inner unions
and intersections that must be sorted in some contexts in our internal
model, but this is not true for the other three variants.
This PR flattens `Type::Callable` into four distinct `Type::` variants.
In the process, it fixes a number of latent bugs that were concealed by
the current architecture but are laid bare by the refactor. Unit tests
for these bugs are included in the PR.
## Summary
Currently if I run `uv run crates/red_knot_python_semantic/mdtest.py`
from the Ruff repo root, I get this output:
```
~/dev/ruff (main)⚡ % uv run crates/red_knot_python_semantic/mdtest.py
Ready to watch for changes...
```
...And I then have to make some spurious whitespace changes or something
to a test file in order to get the script to actually run mdtest. This
PR changes mdtest.py so that it does an initial run of all mdtests when
you invoke the script, and _then_ starts watching for changes in test
files/Rust code.
## Summary
This PR fixes a bug in callable subtyping to consider both the
positional and keyword form of the standard parameter in the supertype
when matching against variadic, keyword-only and keyword-variadic
parameter in the subtype.
This is done by collecting the unmatched standard parameters and then
checking them against the keyword-only / keyword-variadic parameters
after the positional loop.
## Test Plan
Add test cases.
## Summary
There are quite a few places we infer `Todo` types currently, and some
of them are nested somewhat deeply in type expressions. These can cause
spurious issues for the new `redundant-cast` diagnostics. We fixed all
the false positives we saw in the mypy_primer report before merging
https://github.com/astral-sh/ruff/pull/17100, but I think there are
still lots of places where we'd emit false positives due to this check
-- we currently don't run on that many projects at all in our
mypy_primer check:
d0c8eaa092/.github/workflows/mypy_primer.yaml (L71)
This PR fixes some more false positives from this diagnostic by making
the `Type::contains_todo()` method more expansive.
## Test Plan
I added a regression test which causes us to emit a spurious diagnostic
on `main`, but does not with this PR.
## Summary
In https://github.com/python/typeshed/pull/13520 the typeshed definition
of `typing.Any` was changed from `Any = object()` to `class Any: ...`.
Our automated typeshed updater pulled down this change in
https://github.com/astral-sh/ruff/pull/17106, with the consequence that
we no longer understand `Any`, which is... not good.
This PR gives us the ability to understand `Any` defined as a class
instead of `object()`. It doesn't remove our ability to understand the
old form. Perhaps at some point we'll want to remove it, but for now we
may as well support both old and new typeshed?
This also directly patches typeshed to use the new form of `Any`; this
is purely to work around our tests that no known class is inferred as
`Unknown`, which otherwise fail with the old typeshed and the changes in
this PR. (All other tests pass.) This patch to typeshed will shortly be
subsumed by https://github.com/astral-sh/ruff/pull/17106 anyway.
## Test Plan
Without the typeshed change in this PR, all tests pass except for the
two `known_class_doesnt_fallback_to_unknown_unexpectedly_*` tests (so we
still support the old form of defining `Any`). With the typeshed change
in this PR, all tests pass, so we now support the new form in a way that
is indistinguishable to our test suite from the old form. And
indistinguishable to the ecosystem check: after rebasing
https://github.com/astral-sh/ruff/pull/17106 on this PR, there's zero
ecosystem impact.
## Summary
I noticed we were inferring `Todo` as the declared type for annotations
such as `x: tuple[list[int], list[int]]`. This PR reworks our annotation
parsing so that we instead infer `tuple[Todo, Todo]` for this
annotation, which is quite a bit more precise.
## Test Plan
Existing mdtest updated.
## Summary
Following up from earlier discussion on Discord, this PR adds logic to
flag casts as redundant when the inferred type of the expression is the
same as the target type. It should follow the semantics from
[mypy](https://github.com/python/mypy/pull/1705).
Example:
```python
def f() -> int:
return 10
# error: [redundant-cast] "Value is already of type `int`"
cast(int, f())
```
## Summary
Part of #13694
Seems there a bit more to cover regarding `in` and other types, but i
can cover them in different PRs
## Test Plan
Add `in.md` file in narrowing conditionals folder
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Rewrites the virtual env discovery to:
* Only use of `System` APIs, this ensures that the discovery will also
work when using a memory file system (testing or WASM)
* Don't traverse ancestor directories. We're not convinced that this is
necessary. Let's wait until someone shows us a use case where it is
needed
* Start from the project root and not from the current working
directory. This ensures that Red Knot picks up the right venv even when
using `knot --project ../other-dir`
## Test Plan
Existing tests, @ntBre tested that the `file_watching` tests no longer
pick up his virtual env in a parent directory
## Summary
In preparation for #17017, where we will need them to suppress new false
positives (once we understand the `ParamSpec.args`/`ParamSpec.kwargs`
properties).
## Test Plan
Tested on branch #17017
## Summary
Disallow empty `todo_type!()`s without a custom message. They can lead
to spurious diffs in `mypy_primer` where the only thing that's changed
is the file/line information.
## Summary
A quick fix for how union/intersection member search ins performed in
Knot.
## Test Plan
* Added a dunder method call test for Union, which exhibits the error
* Also added an intersection error, but it is not triggering currently
due to `call` logic not being fully implemented for intersections.
---------
Co-authored-by: David Peter <mail@david-peter.de>
## Summary
Closes#16661
This PR includes two changes:
- `NotImplementedType` is now a member of `KnownClass`
- We skip `is_assignable_to` checks for `NotImplemented` when checking
return types
### Limitation
```py
def f(cond: bool) -> int:
return 1 if cond else NotImplemented
```
The implementation covers cases where `NotImplemented` appears inside a
`Union`.
However, for more complex types (ex. `Intersection`) it will not worked.
In my opinion, supporting such complexity is unnecessary at this point.
## Test Plan
Two `mdtest` files were updated:
- `mdtest/function/return_type.md`
- `mdtest/type_properties/is_singleton.md`
To test `KnownClass`, run:
```bash
cargo test -p red_knot_python_semantic -- types::class::
```
## Summary
This PR refactors the common logic for unpacking in assignment, for loops, and with items.
## Test Plan
Make sure existing tests pass.
---------
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
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## Summary
Fixes#16744
Code from
bbf4f830b5/crates/uv-python/src/virtualenv.rs (L124-L144)
## Test Plan
Manual testing
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
## Summary
From #16861, and the continuation of #16915.
This PR fixes the incorrect behavior of
`TypeInferenceBuilder::infer_name_load` in eager nested scopes.
And this PR closes#16341.
## Test Plan
New test cases are added in `annotations/deferred.md`.
## Summary
Part of #13694
Narrow in or-patterns by taking the type union of the type constraints
in each disjunct pattern.
## Test Plan
Add new tests to narrow/match.md
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Part of #13694
The implementation here was suspiciously straightforward so please lmk
if I missed something
Also some drive-by changes to DRY things up a bit
## Test Plan
Add new tests to narrow/match.md
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
This PR adds some branches so that we infer `Todo` types for attribute
access on instances of `super()` and subtypes of `type[Enum]`. It reduces
false positives in the short term until we implement full support for
these features.
## Test Plan
New mdtests added + mypy_primer report
## Summary
Mainly for partially fixing #16953
## Test Plan
Update is_subtype tests. And should maybe do these checks for many other
types (is subtype of object but object is not subtype)
---------
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
## Summary
Further work towards https://github.com/astral-sh/ruff/issues/14169.
We currently panic on encountering cyclic `*` imports. This is easily
fixed using fixpoint iteration.
## Test Plan
Added a test that panics on `main`, but passes with this PR
## Summary
As mentioned in
https://github.com/astral-sh/ruff/pull/16698#discussion_r2004920075,
part of #15382, this PR updates the `is_gradual_equivalent_to`
implementation between callable types to be similar to
`is_equivalent_to` and checks other attributes of parameters like name,
optionality, and parameter kind.
## Test Plan
Expand the existing test cases to consider other properties but not all
similar to how the tests are structured for subtyping and assignability.
## Summary
This PR adds initial support for `*` imports to red-knot. The approach
is to implement a standalone query, called from semantic indexing, that
visits the module referenced by the `*` import and collects all
global-scope public names that will be imported by the `*` import. The
`SemanticIndexBuilder` then adds separate definitions for each of these
names, all keyed to the same `ast::Alias` node that represents the `*`
import.
There are many pieces of `*`-import semantics that are still yet to be
done, even with this PR:
- This PR does not attempt to implement any of the semantics to do with
`__all__`. (If a module defines `__all__`, then only the symbols
included in `__all__` are imported, _not_ all public global-scope
symbols.
- With the logic implemented in this PR as it currently stands, we
sometimes incorrectly consider a symbol bound even though it is defined
in a branch that is statically known to be dead code, e.g. (assuming the
target Python version is set to 3.11):
```py
# a.py
import sys
if sys.version_info < (3, 10):
class Foo: ...
```
```py
# b.py
from a import *
print(Foo) # this is unbound at runtime on 3.11,
# but we currently consider it bound with the logic in this PR
```
Implementing these features is important, but is for now deferred to
followup PRs.
Many thanks to @ntBre, who contributed to this PR in a pairing session
on Friday!
## Test Plan
Assertions in existing mdtests are adjusted, and several new ones are
added.
## Summary
Here I fix the last English spelling errors I could find in the repo.
Again, I am trying not to touch variable/function names, or anything
that might be misspelled in the API. The goal is to make this PR safe
and easy to merge.
## Test Plan
I have run all the unit tests. Though, again, all of the changes I make
here are to docs and docstrings. I make no code changes, which I believe
should greatly mitigate the testing concerns.
## Summary
Resolves#16895.
`abstractmethod` is now a `KnownFunction`. When a function is decorated
by `abstractmethod` or when the parent class inherits directly from
`Protocol`, `invalid-return-type` won't be emitted for that function.
## Test Plan
Markdown tests.
---------
Co-authored-by: Carl Meyer <carl@oddbird.net>
## Summary
Fixes#16912
Create a new type `DisplayMaybeParenthesizedType` that is now used in
Union and Intersection display
## Test Plan
Update callable annotations
## Summary
From #16861
This PR fixes the incorrect `ClassDef` handling of
`SemanticIndexBuilder::visit_stmt`, which fixes some of the incorrect
behavior of referencing the class itself in the class scope (a complete
fix requires a different fix, which will be done in the another PR).
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
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## Summary
This is a cleanup PR. I am fixing various English language spelling
errors. This is mostly in docs and docstrings.
## Test Plan
The usual CI tests were run. I tried to build the docs (though I had
some troubles there). The testing needs here are, I trust, very low
impact. (Though I would happily test more.)
## Summary
Log the origin of the sys path prefix. This should help with debugging
if someone doesn't understand
why Red Knot picks up a certain venv.
## Test Plan
Ran the CLI and tested that it logs the origin
## Summary
Part of #15382, this PR adds support for calling a variable that's
annotated with `typing.Callable`.
## Test Plan
Add test cases in a new `call/annotation.md` file.
## Summary
Part of #15382
This PR adds support for checking the assignability of two general
callable types.
This is built on top of #16804 by including the gradual parameters check
and accepting a function that performs the check between the two types.
## Test Plan
Update `is_assignable_to.md` with callable types section.
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## Summary
When callables are displayed in unions, like:
```py
from typing import Callable
def foo(x: Callable[[], int] | None):
# red-knot: Revealed type is `() -> int | None` [revealed-type]
reveal_type(x)
```
This leaves the type rather ambiguous, to fix this we can add
parenthesis to callable type in union
Fixes#16893
## Test Plan
Update callable annotations tests
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
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.
## 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`
## 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`
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>
## 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.
## 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`
## 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>
## 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
## 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>
## 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
## 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
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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>
## 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
## 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.
## 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.
## 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
## 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.
## 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`
## 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).
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.
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>
## 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.
## 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>
## 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`
## 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
## 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.
## 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.
## 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.)
## 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
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
## 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.
## 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)))
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#13792Fixes#14672
## 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
## 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>
## 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.
## 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
## 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
## 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.
## 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>
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.
## 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`
## 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.
## 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.
## 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`
## 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`
## 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`
## 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`.
## 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>
## 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#16367closes#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.
## 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.
## 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.
## 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"`
## 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.
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>
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.
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.
## 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.
## 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>
## 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>
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.
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>
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.
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.
## 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.
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>
## 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>
## 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
## 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.
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>
## 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
David Peter
Andrew Gallant
Micha Reiser
cake-monotone
Dhruv Manilawala
Matthew Mckee
Alex Waygood
Carl Meyer
Trevor Manz
renovate[bot]
Mike Perlov
Eric Mark Martin
Shunsuke Shibayama
Aleksei Latyshev
John Stilley
InSync
Brent Westbrook
Douglas Creager
Joey Bar
Joey Bar