ruff/crates/red_knot_python_semantic/resources/mdtest/expression
Alex Waygood e87fee4b3b
[red-knot] Add initial support for * imports (#16923)
## 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.
2025-03-24 17:15:58 +00:00
..
assert.md [red-knot] Handle unions of callables better (#16716) 2025-03-17 10:35:52 -04:00
attribute.md [red-knot] Use Unknown | T_inferred for undeclared public symbols (#15674) 2025-01-24 12:47:48 +01:00
boolean.md [red-knot] Handle unions of callables better (#16716) 2025-03-17 10:35:52 -04:00
if.md [red-knot] Add missing imports in mdtests (#15869) 2025-02-03 09:27:29 +00:00
lambda.md Fixing various spelling errors (#16924) 2025-03-23 08:08:40 +00:00
len.md [red-knot] Add initial support for * imports (#16923) 2025-03-24 17:15:58 +00:00