This adds documentation for the new test framework.
I also added documentation for the planned design of features we haven't
built yet (clearly marked as such), so that this doc can become the sole
source of truth for the test framework design (we don't need to refer
back to the original internal design document.)
Also fixes a few issues in the test framework implementation that were
discovered in writing up the docs.
---------
Co-authored-by: T-256 <132141463+T-256@users.noreply.github.com>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Dhruv Manilawala <dhruvmanila@gmail.com>
## Summary
Adds a markdown-based test framework for writing tests of type inference
and type checking. Fixes#11664.
Implements the basic required features. A markdown test file is a suite
of tests, each test can contain one or more Python files, with
optionally specified path/name. The test writes all files to an
in-memory file system, runs red-knot, and matches the resulting
diagnostics against `Type: ` and `Error: ` assertions embedded in the
Python source as comments.
We will want to add features like incremental tests, setting custom
configuration for tests, writing non-Python files, testing syntax
errors, capturing full diagnostic output, etc. There's also plenty of
room for improved UX (colored output?).
## Test Plan
Lots of tests!
Sample of the current output when a test fails:
```
Running tests/inference.rs (target/debug/deps/inference-7c96590aa84de2a4)
running 1 test
test inference::path_1_resources_inference_numbers_md ... FAILED
failures:
---- inference::path_1_resources_inference_numbers_md stdout ----
inference/numbers.md - Numbers - Floats
/src/test.py
line 2: unexpected error: [invalid-assignment] "Object of type `Literal["str"]` is not assignable to `int`"
thread 'inference::path_1_resources_inference_numbers_md' panicked at crates/red_knot_test/src/lib.rs:60:5:
Some tests failed.
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
failures:
inference::path_1_resources_inference_numbers_md
test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.19s
error: test failed, to rerun pass `-p red_knot_test --test inference`
```
---------
Co-authored-by: Micha Reiser <micha@reiser.io>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Fixed a TODO by adding another TODO. It's the red-knot way!
## Summary
`builtins.type` can be subscripted at runtime on Python 3.9+, even
though it has no `__class_getitem__` method and its metaclass (which
is... itself) has no `__getitem__` method. The special case is
[hardcoded directly into `PyObject_GetItem` in
CPython](744caa8ef4/Objects/abstract.c (L181-L184)).
We just have to replicate the special case in our semantic model.
This will fail at runtime on Python <3.9. However, there's a bunch of
outstanding questions (detailed in the TODO comment I added) regarding
how we deal with subscriptions of other generic types on lower Python
versions. Since we want to avoid too many false positives for now, I
haven't tried to address this; I've just made `type` subscriptable on
all Python versions.
## Test Plan
`cargo test -p red_knot_python_semantic --lib`
## Summary
Implements string literal comparisons and fallbacks to `str` instance
for `LiteralString`.
Completes an item in #13618
## Test Plan
- Adds a dedicated test with non exhaustive cases
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Implements the comparison operator for `[Type::IntLiteral]` and
`[Type::BooleanLiteral]` (as an artifact of special handling of `True` and
`False` in python).
Sets the framework to implement more comparison for types known at
static time (e.g. `BooleanLiteral`, `StringLiteral`), allowing us to only
implement cases of the triplet `<left> Type`, `<right> Type`, `CmpOp`.
Contributes to #12701 (without checking off an item yet).
## Test Plan
- Added a test for the comparison of literals that should include most
cases of note.
- Added a test for the comparison of int instances
Please note that the cases do not cover 100% of the branches as there
are many and the current testing strategy with variables make this
fairly confusing once we have too many in one test.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
...and remove periods from messages that don't span more than a single
sentence.
This is more consistent with how we present user-facing messages in uv
(which has a defined style guide).
## Summary
You can now call `return_ty_result` to operate on a `Result` directly
thereby using your own diagnostics, as in:
```rust
return dunder_getitem_method
.call(self.db, &[slice_ty])
.return_ty_result(self.db, value.as_ref().into(), self)
.unwrap_or_else(|err| {
self.add_diagnostic(
(&**value).into(),
"call-non-callable",
format_args!(
"Method `__getitem__` is not callable on object of type '{}'.",
value_ty.display(self.db),
),
);
err.return_ty()
});
```
Adds a diagnostic for division by the integer zero in `//`, `/`, and
`%`.
Doesn't handle `<int> / 0.0` because we don't track the values of float
literals.
This variant shows inference that is not yet implemented..
## Summary
PR #13500 reopened the idea of adding a new type variant to keep track
of not-implemented features in Red Knot.
It was based off of #12986 with a more generic approach of keeping track
of different kind of unknowns. Discussion in #13500 agreed that keeping
track of different `Unknown` is complicated for now, and this feature is
better achieved through a new variant of `Type`.
### Requirements
Requirements for this implementation can be summed up with some extracts
of comment from @carljm on the previous PR
> So at the moment we are leaning towards simplifying this PR to just
use a new top-level variant, which behaves like Any and Unknown but
represents inference that is not yet implemented in red-knot.
> I think the general rule should be that Todo should propagate only
when the presence of the input Todo caused the output to be unknown.
>
> To take a specific example, the inferred result of addition must be
Unknown if either operand is Unknown. That is, Unknown + X will always
be Unknown regardless of what X is. (Same for X + Unknown.) In this
case, I believe that Unknown + Todo (or Todo + Unknown) should result in
Unknown, not result in Todo. If we fix the upstream source of the Todo,
the result would still be Unknown, so it's not useful to propagate the
Todo in this case: it wrongly suggests that the output is unknown
because of a todo item.
## Test Plan
This PR does not introduce new tests, but it did required to edit some
tests with the display of `[Type::Todo]` (currently `@Todo`), which
suggests that those test are placeholders requirements for features we
don't support yet.
While working on https://github.com/astral-sh/ruff/pull/13576 I noticed
that it was really hard to tell which assertion failed in some of these
test cases. This could be expanded to elsewhere, but I've heard this
test suite format won't be around for long?
## Summary
Following #13449, this PR adds custom handling for the bool constructor,
so when the input type has statically known truthiness value, it will be
used as the return value of the bool function.
For example, in the following snippet x will now be resolved to
`Literal[True]` instead of `bool`.
```python
x = bool(1)
```
## Test Plan
Some cargo tests were added.
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## Summary
Implement inference for `f-string`, contributes to #12701.
### First Implementation
When looking at the way `mypy` handles things, I noticed the following:
- No variables (e.g. `f"hello"`) ⇒ `LiteralString`
- Any variable (e.g. `f"number {1}"`) ⇒ `str`
My first commit (1ba5d0f13fdf70ed8b2b1a41433b32fc9085add2) implements
exactly this logic, except that we deal with string literals just like
`infer_string_literal_expression` (if below `MAX_STRING_LITERAL_SIZE`,
show `Literal["exact string"]`)
### Second Implementation
My second commit (90326ce9af5549af7b4efae89cd074ddf68ada14) pushes
things a bit further to handle cases where the expression within the
`f-string` are all literal values (string representation known at static
time).
Here's an example of when this could happen in code:
```python
BASE_URL = "https://httpbin.org"
VERSION = "v1"
endpoint = f"{BASE_URL}/{VERSION}/post" # Literal["https://httpbin.org/v1/post"]
```
As this can be sightly more costly (additional allocations), I don't
know if we want this feature.
## Test Plan
- Added a test `fstring_expression` covering all cases I can think of
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
This PR changes removes the typeshed stubs from the vendored file system
shipped with ruff
and instead ships an empty "typeshed".
Making the typeshed files optional required extracting the typshed files
into a new `ruff_vendored` crate. I do like this even if all our builds
always include typeshed because it means `red_knot_python_semantic`
contains less code that needs compiling.
This also allows us to use deflate because the compression algorithm
doesn't matter for an archive containing a single, empty file.
## Test Plan
`cargo test`
I verified with ` cargo tree -f "{p} {f}" -p <package> ` that:
* red_knot_wasm: enables `deflate` compression
* red_knot: enables `zstd` compression
* `ruff`: uses stored
I'm not quiet sure how to build the binary that maturin builds but
comparing the release artifact size with `strip = true` shows a `1.5MB`
size reduction
---------
Co-authored-by: Charlie Marsh <charlie.r.marsh@gmail.com>
Avoid quadratic time in subsumed elements when adding a super-type of
existing union elements.
Reserve space in advance when adding multiple elements (from another
union) to a union.
Make union elements a `Box<[Type]>` instead of an `FxOrderSet`; the set
doesn't buy much since the rules of union uniqueness are defined in
terms of supertype/subtype, not in terms of simple type identity.
Move sealed-boolean handling out of a separate `UnionBuilder::simplify`
method and into `UnionBuilder::add`; now that `add` is iterating
existing elements anyway, this is more efficient.
Remove `UnionType::contains`, since it's now `O(n)` and we shouldn't
really need it, generally we care about subtype/supertype, not type
identity. (Right now it's used for `Type::Unbound`, which shouldn't even
be a type.)
Add support for `is_subtype_of` for the `object` type.
Addresses comments on https://github.com/astral-sh/ruff/pull/13401
This was mentioned in an earlier review, and seemed easy enough to just
do it. No need to repeat all the types twice when it gives no additional
information.
## Summary
This PR adds an experimental Ruff subcommand to generate dependency
graphs based on module resolution.
A few highlights:
- You can generate either dependency or dependent graphs via the
`--direction` command-line argument.
- Like Pants, we also provide an option to identify imports from string
literals (`--detect-string-imports`).
- Users can also provide additional dependency data via the
`include-dependencies` key under `[tool.ruff.import-map]`. This map uses
file paths as keys, and lists of strings as values. Those strings can be
file paths or globs.
The dependency resolution uses the red-knot module resolver which is
intended to be fully spec compliant, so it's also a chance to expose the
module resolver in a real-world setting.
The CLI is, e.g., `ruff graph build ../autobot`, which will output a
JSON map from file to files it depends on for the `autobot` project.
This fixes the last panic on checking pandas.
(Match statement became an `if let` because clippy decided it wanted
that once I added the additional line in the else case?)
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Support using `reveal_type` without importing it, as implied by the type
spec and supported by existing type checkers.
We use `typing_extensions.reveal_type` for the implicit built-in; this
way it exists on all Python versions. (It imports from `typing` on newer
Python versions.)
Emits an "undefined name" diagnostic whenever `reveal_type` is
referenced in this way (in addition to the revealed-type diagnostic when
it is called). This follows the mypy example (with `--enable-error-code
unimported-reveal`) and I think provides a good (and easily
understandable) balance for user experience. If you are using
`reveal_type` for quick temporary debugging, the additional
undefined-name diagnostic doesn't hinder that use case. If we make the
revealed-type diagnostic a non-failing one, the undefined-name
diagnostic can still be a failing diagnostic, helping prevent
accidentally leaving it in place. For any use cases where you want to
leave it in place, you can always import it to avoid the undefined-name
diagnostic.
In the future, we can easily provide configuration options to a) turn
off builtin-reveal_type altogether, and/or b) silence the undefined-name
diagnostic when using it, if we have users on either side (loving or
hating pseudo-builtin `reveal_type`) who are dissatisfied with this
compromise.
After looking at more cases (for example, the case in the added test in
this PR), I realized that our previous rule, "if a symbol has any
declarations, use only declarations for its public type" is not
adequate. Rather than using `Unknown` as fallback if the symbol is not
declared in some paths, we need to use the inferred type as fallback in
that case.
For the paths where the symbol _was_ declared, we know that any bindings
must be assignable to the declared type in that path, so this won't
change the overall declared type in those paths. But for paths where the
symbol wasn't declared, this will give us a better type in place of
`Unknown`.
Before `typing.reveal_type` existed, there was
`typing_extensions.reveal_type`. We should support both.
Also adds a test to verify that we can handle aliasing of `reveal_type`
to a different name.
Adds a bit of code to ensure that if we have a union of different
`reveal_type` functions (e.g. a union containing both
`typing_extensions.reveal_type` and `typing.reveal_type`) we still emit
the reveal-type diagnostic only once. This is probably unlikely in
practice, but it doesn't hurt to handle it smoothly. (It comes up now
because we don't support `version_info` checks yet, so
`typing_extensions.reveal_type` is actually that union.)
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
I noticed that this pattern sometimes occurs in typeshed:
```
if ...:
from foo import bar
else:
def bar(): ...
```
If we have the rule that symbols with declarations only use declarations
for the public type, then this ends up resolving as `Unknown |
Literal[bar]`, because we didn't consider the import to be a
declaration.
I think the most straightforward thing here is to also consider imports
as declarations. The same rationale applies as for function and class
definitions: if you shadow an import, you should have to explicitly
shadow with an annotation, rather than just doing it
implicitly/accidentally.
We may also ultimately need to re-evaluate the rule that public type
considers only declarations, if there are declarations.
Add support for the `typing.reveal_type` function, emitting a diagnostic
revealing the type of its single argument. This is a necessary piece for
the planned testing framework.
This puts the cart slightly in front of the horse, in that we don't yet
have proper support for validating call signatures / argument types. But
it's easy to do just enough to make `reveal_type` work.
This PR includes support for calling union types (this is necessary
because we don't yet support `sys.version_info` checks, so
`typing.reveal_type` itself is a union type), plus some nice
consolidated error messages for calls to unions where some elements are
not callable. This is mostly to demonstrate the flexibility in
diagnostics that we get from the `CallOutcome` enum.
Use declared types in inference and checking. This means several things:
* Imports prefer declarations over inference, when declarations are
available.
* When we encounter a binding, we check that the bound value's inferred
type is assignable to the live declarations of the bound symbol, if any.
* When we encounter a declaration, we check that the declared type is
assignable from the inferred type of the symbol from previous bindings,
if any.
* When we encounter a binding+declaration, we check that the inferred
type of the bound value is assignable to the declared type.
Add support for declared types to the semantic index. This involves a
lot of renaming to clarify the distinction between bindings and
declarations. The Definition (or more specifically, the DefinitionKind)
becomes responsible for determining which definitions are bindings,
which are declarations, and which are both, and the symbol table
building is refactored a bit so that the `IS_BOUND` (renamed from
`IS_DEFINED` for consistent terminology) flag is always set when a
binding is added, rather than being set separately (and requiring us to
ensure it is set properly).
The `SymbolState` is split into two parts, `SymbolBindings` and
`SymbolDeclarations`, because we need to store live bindings for every
declaration and live declarations for every binding; the split lets us
do this without storing more than we need.
The massive doc comment in `use_def.rs` is updated to reflect bindings
vs declarations.
The `UseDefMap` gains some new APIs which are allow-unused for now,
since this PR doesn't yet update type inference to take declarations
into account.
Add `::is_empty` and `::union` methods to the `BitSet` implementation.
Allowing unused for now, until these methods become used later with the
declared-types implementation.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
These are quite incomplete, but I needed to start stubbing them out in
order to build and test declared-types.
Allowing unused for now, until they are used later in the declared-types
PR.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
This PR adds a new `Type` variant called `TupleType` which is used for
heterogeneous elements.
### Display notes
* For an empty tuple, I'm using `tuple[()]` as described in the docs:
https://docs.python.org/3/library/typing.html#annotating-tuples
* For nested elements, it'll use the literal type instead of builtin
type unlike Pyright which does `tuple[Literal[1], tuple[int, int]]`
instead of `tuple[Literal[1], tuple[Literal[2], Literal[3]]]`. Also,
mypy would give `tuple[builtins.int, builtins.int]` instead of
`tuple[Literal[1], Literal[2]]`
## Test Plan
Update test case to account for the display change and add cases for
multiple elements and nested tuple elements.
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
This PR adds support for control flow for match statement.
It also adds the necessary infrastructure required for narrowing
constraints in case blocks and implements the logic for
`PatternMatchSingleton` which is either `None` / `True` / `False`. Even
after this the inferred type doesn't get simplified completely, there's
a TODO for that in the test code.
## Test Plan
Add test cases for control flow for (a) when there's a wildcard pattern
and (b) when there isn't. There's also a test case to verify the
narrowing logic.
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
When a type of the form `Literal["..."]` would be constructed with too
large of a string, this PR converts it to `LiteralString` instead.
We also extend inference for binary operations to include the case where
one of the operands is `LiteralString`.
Closes#13224
Pull the tests from `types.rs` into `infer.rs`.
All of these are integration tests with the same basic form: create a
code sample, run type inference or check on it, and make some assertions
about types and/or diagnostics. These are the sort of tests we will want
to move into a test framework with a low-boilerplate custom textual
format. In the meantime, having them together (and more importantly,
their helper utilities together) means that it's easy to keep tests for
related language features together (iterable tests with other iterable
tests, callable tests with other callable tests), without an artificial
split based on tests which test diagnostics vs tests which test
inference. And it allows a single test to more easily test both
diagnostics and inference. (Ultimately in the test framework, they will
likely all test diagnostics, just in some cases the diagnostics will
come from `reveal_type()`.)
My plan for handling declared types is to introduce a `Declaration` in
addition to `Definition`. A `Declaration` is an annotation of a name
with a type; a `Definition` is an actual runtime assignment of a value
to a name. A few things (an annotated function parameter, an
annotated-assignment with an RHS) are both a `Definition` and a
`Declaration`.
This more cleanly separates type inference (only cares about
`Definition`) from declared types (only impacted by a `Declaration`),
and I think it will work out better than trying to squeeze everything
into `Definition`. One of the tests in this PR
(`annotation_only_assignment_transparent_to_local_inference`)
demonstrates one reason why. The statement `x: int` should have no
effect on local inference of the type of `x`; whatever the locally
inferred type of `x` was before `x: int` should still be the inferred
type after `x: int`. This is actually quite hard to do if `x: int` is
considered a `Definition`, because a core assumption of the use-def map
is that a `Definition` replaces the previous value. To achieve this
would require some hackery to effectively treat `x: int` sort of as if
it were `x: int = x`, but it's not really even equivalent to that, so
this approach gets quite ugly.
As a first step in this plan, this PR stops treating AnnAssign with no
RHS as a `Definition`, which fixes behavior in a couple added tests.
This actually makes things temporarily worse for the ellipsis-type test,
since it is defined in typeshed only using annotated assignments with no
RHS. This will be fixed properly by the upcoming addition of
declarations, which should also treat a declared type as sufficient to
import a name, at least from a stub.
Initially I had deferred annotation name lookups reuse the "public
symbol type", since that gives the correct "from end of scope" view of
reaching definitions that we want. But there is a key difference; public
symbol types are based only on definitions in the queried scope (or
"name in the given namespace" in runtime terms), they don't ever look up
a name in nonlocal/global/builtin scopes. Deferred annotation resolution
should do this lookup.
Add a test, and fix deferred name resolution to support
nonlocal/global/builtin names.
Fixes#13176
## Summary
Part of #13085, this PR updates the comprehension definition to handle
multiple targets.
## Test Plan
Update existing semantic index test case for comprehension with multiple
targets. Running corpus tests shouldn't panic.
Add support for non-local name lookups.
There's one TODO around annotated assignments without a RHS; these need
a fair amount of attention, which they'll get in an upcoming PR about
declared vs inferred types.
Fixes#11663
Test coverage for #13131 wasn't as good as I thought it was, because
although we infer a lot of types in stubs in typeshed, we don't check
typeshed, and therefore we don't do scope-level inference and pull all
types for a scope. So we didn't really have good test coverage for
scope-level inference in a stub. And because of this, I got the code for
supporting that wrong, meaning that if we did scope-level inference with
deferred types, we'd end up never populating the deferred types in the
scope's `TypeInference`, which causes panics like #13160.
Here I both add test coverage by running the corpus tests both as `.py`
and as `.pyi` (which reveals the panic), and I fix the code to support
deferred types in scope inference.
This also revealed a problem with deferred types in generic functions,
which effectively span two scopes. That problem will require a bit more
thought, and I don't want to block this PR on it, so for now I just
don't defer annotations on generic functions.
Fixes#13160.
## Summary
Follow-up to #13147, this PR implements the `AstNode` for `Identifier`.
This makes it easier to create the `NodeKey` in red knot because it uses
a generic method to construct the key from `AnyNodeRef` and is important
for definitions that are created only on identifiers instead of
`ExprName`.
## Test Plan
`cargo test` and `cargo clippy`
## Summary
This PR adds definition for match patterns.
## Test Plan
Update the existing test case for match statement symbols to verify that
the definitions are added as well.
The `UnionBuilder` builds `builtins.bool` when handed `Literal[True]`
and `Literal[False]`.
Caveat: If the builtins module is unfindable somehow, the builder falls
back to the union type of these two literals.
First task from #12694
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
Adds basic support for inferring the type resulting from a call
expression. This only works for the *result* of call expressions; it
performs no inference on parameters. It also intentionally does nothing
with class instantiation, `__call__` implementors, or lambdas.
## Test Plan
Adds a test that it infers the right thing!
---------
Co-authored-by: Carl Meyer <carl@astral.sh>
## Summary
- Introduce methods for inferring annotation and type expressions.
- Correctly infer explicit return types from functions where they are
simple names that can be resolved in scope.
Contributes to #12701 by way of helping unlock call expressions (this
does not remotely finish that, as it stands, but it gets us moving that
direction).
## Test Plan
Added a test for function return types which use the name form of an
annotation expression, since this is aiming toward call expressions.
When we extend this to working for other annotation and type expression
positions, we should add explicit tests for those as well.
---------
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
Prototype deferred evaluation of type expressions by deferring
evaluation of class bases in a stub file. This allows self-referential
class definitions, as occur with the definition of `str` in typeshed
(which inherits `Sequence[str]`).
---------
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
## Summary
Just what it says on the tin: adds basic `EllipsisType` inference for
any time `...` appears in the AST.
## Test Plan
Test that `x = ...` produces exactly what we would expect.
---------
Co-authored-by: Carl Meyer <carl@oddbird.net>
## Summary
The resulting type when multiplying a string literal by an integer
literal is one of two types:
- `StringLiteral`, in the case where it is a reasonably small resulting
string (arbitrarily bounded here to 4096 bytes, roughly a page on many
operating systems), including the fully expanded string.
- `LiteralString`, matching Pyright etc., for strings larger than that.
Additionally:
- Switch to using `Box<str>` instead of `String` for the internal value
of `StringLiteral`, saving some non-trivial byte overhead (and keeping
the total number of allocations the same).
- Be clearer and more accurate about which types we ought to defer to in
`StringLiteral` and `LiteralString` member lookup.
## Test Plan
Added a test case covering multiplication times integers: positive,
negative, zero, and in and out of bounds.
---------
Co-authored-by: Alex Waygood <alex.waygood@gmail.com>
Co-authored-by: Carl Meyer <carl@astral.sh>
Micha Reiser
David Peter
Alex Waygood
Carl Meyer
renovate[bot]
Simon
Charlie Marsh
Zanie Blue
aditya pillai
TomerBin
haarisr
Hamir Mahal
github-actions[bot]
Dhruv Manilawala
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