Commit graph

16 commits

Author SHA1 Message Date
David Peter
5fef4d4572
Use python.typing.org for typing documentation links (#17323)
## Summary

There is a new official URL for the typing documentation:
https://typing.python.org/

Change all https://typing.readthedocs.io/ links to use the new sub
domain, which is slightly shorter and looks more official.

## Test Plan

Tested to see if each and every new URL is accessible. I noticed that
some links go to https://typing.python.org/en/latest/source/stubs.html
which seems to be outdated, but that is a separate issue. The same page
shows up for the old URL.
2025-04-09 20:38:20 +02:00
David Peter
ae2cf91a36
[red-knot] Decorators and properties (#17017)
## 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.
2025-04-02 09:27:46 +02:00
David Peter
820a31af5d
[red-knot] Attribute access and the descriptor protocol (#16416)
## Summary

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

closes #16367
closes #15966

## Context

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

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

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

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

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

## Test Plan

New Markdown tests.
2025-03-07 22:03:28 +01:00
David Peter
d296f602e7
[red-knot] Merge Markdown code blocks inside a single section (#15950)
## Summary

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

closes #15941

## Test Plan

- Interactively made sure that error-lines were reported correctly in
  multi-snippet sections.
2025-02-05 22:26:15 +01:00
David Peter
24c1cf71cb
[red-knot] Use unambiguous invalid-syntax-construct for suppression comment test (#15933)
## Summary

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

I was surprised to see some test failures when I played with this
though, and decided to make this test independent from this
implementation detail.
2025-02-04 15:24:50 +01:00
InSync
11cfe2ea8a
[red-knot] Enforce specifying paths for mdtest code blocks in a separate preceding line (#15890)
## Summary

Resolves #15695, rework of #15704.

This change modifies the Mdtests framework so that:

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

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

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

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

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

Additionally, all legacy usages have been updated.

## Test Plan

Unit tests and Markdown tests.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
2025-02-04 08:27:17 +01:00
Alex Waygood
3125332ec1
[red-knot] Format mdtest snippets with the latest version of black (#15819) 2025-01-29 23:05:43 +00:00
Micha Reiser
4e3982cf95
[red-knot] Add --ignore, --warn, and --error CLI arguments (#15689) 2025-01-24 16:20:15 +01:00
Micha Reiser
0caab81d3d
@no_type_check support (#15122)
Co-authored-by: Carl Meyer <carl@astral.sh>
2024-12-30 09:42:18 +00:00
Micha Reiser
6ed27c3786
Rename the knot|type-ignore mdtest files (#15147) 2024-12-26 10:25:05 +00:00
Micha Reiser
8d327087ef
Add invalid-ignore-comment rule (#15094) 2024-12-23 10:38:10 +00:00
Micha Reiser
2835d94ec5
Add unknown-rule (#15085)
Co-authored-by: Carl Meyer <carl@astral.sh>
2024-12-23 11:30:54 +01:00
Micha Reiser
2a99c0be02
Add unused-ignore-comment rule (#15084) 2024-12-23 11:15:28 +01:00
Micha Reiser
1c3d11e8a8
Support file-level type: ignore comments (#15081) 2024-12-23 09:59:04 +00:00
Micha Reiser
2f85749fa0
type: ignore[codes] and knot: ignore (#15078) 2024-12-23 10:52:43 +01:00
Micha Reiser
913bce3cd5
Basic support for type: ignore comments (#15046)
## Summary

This PR adds initial support for `type: ignore`. It doesn't do anything
fancy yet like:

* Detecting invalid type ignore comments
* Detecting type ignore comments that are part of another suppression
comment: `# fmt: skip # type: ignore`
* Suppressing specific lints `type: ignore [code]`
* Detecting unsused type ignore comments
* ...

The goal is to add this functionality in separate PRs.

## Test Plan

---------

Co-authored-by: Carl Meyer <carl@astral.sh>
Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>
2024-12-20 10:35:09 +01:00