## Summary
Given a statement like `colors = 6`, we currently treat the cell as an
automagic (since `colors` is an automagic) -- i.e., we assume it's
equivalent to `%colors = 6`. This PR adds some additional detection
whereby if the statement is an _assignment_, we avoid treating it as
such. I audited the list of automagics, and I believe this is safe for
all of them.
Closes https://github.com/astral-sh/ruff/issues/8526.
Closes https://github.com/astral-sh/ruff/issues/9648.
## Test Plan
`cargo test`
The example below used to panic because we tried to split at 2 bytes in
the 4-bytes character `转`.
```python
def sample_func(xx):
"""
转置 (transpose)
"""
return xx.T
```
Fixes#9145
Fixes https://github.com/astral-sh/ruff-vscode/issues/362
The second commit is a small test refactoring.
## Summary
This PR updates the logic for `is_magic_cell` to include certain cell
magics. These cell magics would contain Python code following the line
defining the command. The code could define a variable which can then be
referenced in other cells. Currently, we would ignore the cell
completely leading to undefined-name violation.
As discussed in
https://github.com/astral-sh/ruff/issues/8354#issuecomment-1832221009
## Test Plan
Add new test case to validate this scenario.
## Summary
This PR updates the `E402` rule to work at cell level for Jupyter
notebooks. This is enabled only in preview to gather feedback.
The implementation basically resets the import boundary flag on the
semantic model when we encounter the first statement in a cell.
Another potential solution is to introduce `E403` rule that is
specifically for notebooks that works at cell level while `E402` will be
disabled for notebooks.
## Test Plan
Add a notebook with imports in multiple cells and verify that the rule
works as expected.
resolves: #8669
## Summary
This PR updates `B015` and `B018` to ignore last top-level expressions
in each cell of a Jupyter Notebook.
Part of #8669
## Test Plan
Add test cases for both rules and update the snapshots.
