## Summary
Adds a type-check-time Python API that allows us to create and
manipulate types and to test various of their properties. For example,
this can be used to write a Markdown test to make sure that `A & B` is a
subtype of `A` and `B`, but not of an unrelated class `C` (something
that requires quite a bit more code to do in Rust):
```py
from knot_extensions import Intersection, is_subtype_of, static_assert
class A: ...
class B: ...
type AB = Intersection[A, B]
static_assert(is_subtype_of(AB, A))
static_assert(is_subtype_of(AB, B))
class C: ...
static_assert(not is_subtype_of(AB, C))
```
I think this functionality is also helpful for interactive debugging
sessions, in order to query various properties of Red Knot's type
system. Which is something that otherwise requires a custom Rust unit
test, some boilerplate code and constant re-compilation.
## Test Plan
- New Markdown tests
- Tested the modified typeshed_sync workflow locally
## Summary
`Type[Any]` should be assignable to `object`. All types should be
assignable to `object`.
We specifically didn't understand the former; this PR adds a test for
it, and a case to ensure that `Type[Any]` is assignable to anything that
`type` is assignable to (which includes `object`).
This PR also adds a property test that all types are assignable to
object. In order to make it pass, I added a special case to check early
if we are assigning to `object` and just return `true`. In principle,
once we get all the more general cases correct, this special case might
be removable. But having the special case for now allows the property
test to pass.
And we add a property test that all types are subtypes of object. This
failed for the case of an intersection with no positive elements (that
is, a negation type). This really does need to be a special case for
`object`, because there is no other type we can know that a negation
type is a subtype of.
## Test Plan
Added unit test and property test.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
When removing `int` in calls like `int(expr)` we may need to keep
parentheses around `expr` even when it is a function call or subscript,
since there may be newlines in between the function/value name and the
opening parentheses/bracket of the argument.
This PR implements that logic.
Closes#15263
---------
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
We now support class patterns in a match statement, adding a narrowing
constraint that within the body of that match arm, we can assume that
the subject is an instance of that class.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Micha Reiser <micha@reiser.io>
## Summary
This implements checking of calls.
I ended up following Micha's original suggestion from back when the
signature representation was first introduced, and flattening it to a
single array of parameters. This turned out to be easier to manage,
because we can represent parameters using indices into that array, and
represent the bound argument types as an array of the same length.
Starred and double-starred arguments are still TODO; these won't be very
useful until we have generics.
The handling of diagnostics is just hacked into `return_ty_result`,
which was already inconsistent about whether it emitted diagnostics or
not; now it's even more inconsistent. This needs to be addressed, but
could be a follow-up.
The new benchmark errors here surface the need for intersection support
in `is_assignable_to`.
Fixes#14161.
## Test Plan
Added mdtests.
Note: `PLW0101` remains in testing rather than preview, so this PR does
not modify any public behavior (hence the title beginning with
`internal` rather than `pylint`, for the sake of the changelog.)
Fixes an error in the processing of `try` statements in the control flow
graph builder.
When processing a try statement, the block following a `return` was
forced to point to the `finally` block. However, if the return was _in_
the `finally` block, this caused the block to point to itself. In the
case where the whole `try-finally` statement was also included inside of
a loop, this caused an infinite loop in the builder for the control flow
graph as it attempted to resolve edges.
Closes#15248
## Test function
### Source
```python
def l():
while T:
try:
while ():
if 3:
break
finally:
return
```
### Control Flow Graph
```mermaid
flowchart TD
start(("Start"))
return(("End"))
block0[["`*(empty)*`"]]
block1[["Loop continue"]]
block2["return\n"]
block3[["Loop continue"]]
block4["break\n"]
block5["if 3:
break\n"]
block6["while ():
if 3:
break\n"]
block7[["Exception raised"]]
block8["try:
while ():
if 3:
break
finally:
return\n"]
block9["while T:
try:
while ():
if 3:
break
finally:
return\n"]
start --> block9
block9 -- "T" --> block8
block9 -- "else" --> block0
block8 -- "Exception raised" --> block7
block8 -- "else" --> block6
block7 --> block2
block6 -- "()" --> block5
block6 -- "else" --> block2
block5 -- "3" --> block4
block5 -- "else" --> block3
block4 --> block2
block3 --> block6
block2 --> return
block1 --> block9
block0 --> return
```
## Summary
When debugging, I frequently want to know which symbols are being looked
up. `symbol_by_id` adds tracing information, but it only shows the
`ScopedSymbolId`. Since `symbol_by_id` is only called from `symbol`, it
seems reasonable to move the tracing call one level up from
`symbol_by_id` to `symbol`, where we can also show the name of the
symbol.
**Before**:
```
6 └─┐red_knot_python_semantic::types::infer::infer_expression_types{expression=Id(60de), file=/home/shark/tomllib_modified/_parser.py}
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(33)}
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(123)}
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(54)}
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(122)}
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(165)}
6 ┌─┘
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(32)}
6 ┌─┘
6 └─┐red_knot_python_semantic::types::symbol_by_id{symbol=ScopedSymbolId(232)}
6 ┌─┘
6 ┌─┘
6 ┌─┘
6┌─┘
```
**After**:
```
5 └─┐red_knot_python_semantic::types::infer::infer_expression_types{expression=Id(60de), file=/home/shark/tomllib_modified/_parser.py}
5 └─┐red_knot_python_semantic::types::symbol{name="dict"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="dict"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="list"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="list"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="isinstance"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="isinstance"}
5 ┌─┘
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="ValueError"}
5 ┌─┘
5 └─┐red_knot_python_semantic::types::symbol{name="ValueError"}
5 ┌─┘
5 ┌─┘
5 ┌─┘
5┌─┘
```
## Test Plan
```
cargo run --bin red_knot -- --current-directory path/to/tomllib -vvv
```
## Summary
While looking at #14899, I looked at seeing if I could get shrinking on
the examples. It turned out to be straightforward, with a couple of
caveats.
I'm calling `clone` a lot during shrinking. Since by the shrink step
we're already looking at a test failure this feels fine? Unless I
misunderstood `quickcheck`'s core loop
When shrinking `Intersection`s, in order to just rely on `quickcheck`'s
`Vec` shrinking without thinking about it too much, the shrinking
strategy is:
- try to shrink the negative side (keeping the positive side the same)
- try to shrink the positive side (keeping the negative side the same)
This means that you can't shrink from `(A & B & ~C & ~D)` directly to
`(A & ~C)`! You would first need an intermediate failure at `(A & B &
~C)` or `(A & ~C & ~D)`. This feels good enough. Shrinking the negative
side first also has the benefit of trying to strip down negative
elements in these intersections.
## Test Plan
`cargo test -p red_knot_python_semantic -- --ignored
types::property_tests::stable` still fails as it current does on `main`,
but now the errors seem more minimal.
## Summary
Adds `class-as-data-structure` rule (`B903`). Also compare pylint's `too-few-public-methods` (`PLR0903`).
Took some creative liberty with this by allowing the class to have any
decorators or base classes. There are years-old issues on pylint that
don't approve of the strictness when it comes to these things.
Especially considering that dataclass is a decorator and namedtuple _can
be_ a base class. I feel ignoring those explicitly is redundant all
things considered, but it's not a hill I'm willing to die on!
See: #970
## Test Plan
`cargo test`
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: dylwil3 <dylwil3@gmail.com>
Just like in #15045 for unary expressions: In binary expressions, we
were only looking for dunder expressions for `Type::Instance` types. We
had some special cases for coercing the various `Literal` types into
their corresponding `Instance` types before doing the lookup. But we can
side-step all of that by using the existing `Type::to_meta_type` and
`Type::to_instance` methods.
## Summary
This PR upgrades zizmor to the latest release in our CI. zizmor is a
static analyzer checking for security issues in GitHub workflows. The
new release finds some new issues in our workflows; this PR fixes some
of the issues, and adds ignores for some other issues.
The issues fixed in this PR are new cases of zizmor's
[`template-injection`](https://woodruffw.github.io/zizmor/audits/#template-injection)
rule being emitted. The issues I'm ignoring for now are all to do with
the
[`cache-poisoning`](https://woodruffw.github.io/zizmor/audits/#cache-poisoning)
rule. The main reason I'm fixing some but ignoring others is that I'm
confident fixing the template-injection diagnostics won't have any
impact on how our workflows operate in CI, but I'm worried that fixing
the cache-poisoning diagnostics could slow down our CI a fair bit. I
don't mind if somebody else is motivated to try to fix these
diagnostics, but for now I think I'd prefer to just ignore them; it
doesn't seem high-priority enough to try to fix them right now :-)
## Test Plan
- `uvx pre-commit run -a --hook-stage=manual` passes locally
- Let's see if CI passes on this PR...
Resolves#14840
## Summary
Usage of ellipsis literal as default argument is allowed in stub files.
## Test Plan
Added mdtest for both python files and stub files.
---------
Co-authored-by: Carl Meyer <carl@oddbird.net>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
The test expression in an `elif` clause is evaluated whether or not we
take the branch. Our control flow model for if/elif chains failed to
reflect this, causing wrong inference in cases where an assignment
expression occurs inside an `elif` test expression. Our "no branch taken
yet" snapshot (which is the starting state for every new elif branch)
can't simply be the pre-if state, it must be updated after visiting each
test expression.
Once we do this, it also means we no longer need to track a vector of
narrowing constraints to reapply for each new branch, since our "branch
not taken" state (which is the initial state for each branch) is
continuously updated to include the negative narrowing constraints of
all previous branches.
Fixes#15033.
## Test Plan
Added mdtests.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
