ruff/crates/ty_python_semantic/resources/mdtest/import/cyclic.md

Cyclic imports

Regression tests

Issue 261

See: https://github.com/astral-sh/ty/issues/261

main.py:

from foo import bar

reveal_type(bar)  # revealed: <module 'foo.bar'>

foo/__init__.py:

from foo import bar

__all__ = ["bar"]

foo/bar/__init__.py:

# empty

Issue 113

See: https://github.com/astral-sh/ty/issues/113

main.py:

from pkg.sub import A

# TODO: This should be `<class 'A'>`
reveal_type(A)  # revealed: Never

pkg/outer.py:

class A: ...

pkg/sub/__init__.py:

from ..outer import *
from .inner import *

pkg/sub/inner.py:

from pkg.sub import A

Actual cycle

The following example fails at runtime. Ideally, we would emit a diagnostic here. For now, we only make sure that this does not lead to a module resolution cycle.

main.py:

from module import x

reveal_type(x)  # revealed: Unknown

module.py:

# error: [unresolved-import]
from module import x

Normal self-referential import

Some modules like sys in typeshed import themselves. Here, we make sure that this does not lead to cycles or unresolved imports.

module/__init__.py:

import module  # self-referential import

from module.sub import x

module/sub.py:

x: int = 1

main.py:

from module import x

reveal_type(x)  # revealed: int