jinja_loader type bug #5388
Description
I have
from jinja2 import ChoiceLoader, FileSystemLoader
app.jinja_loader = ChoiceLoader([
FileSystemLoader(project_dir / 'templates/'),
app.jinja_loader,
])There is a mypy error
error: Incompatible types in assignment (expression has type "ChoiceLoader", variable has type "FileSystemLoader | None") [assignment]
error: List item 1 has incompatible type "FileSystemLoader | None"; expected "BaseLoader" [list-item]
There shouldn't be an error.
Environment:
- Python version: 3.12.1
- Flask version: 3.0.1