Remove unnecessary uses of `.as_ref()`, `.iter()`, `&**` and similar, mostly in situations when iterating over variables. Many of these changes are only possible following #13826, when we bumped our MSRV to 1.80: several useful implementations on `&Box<[T]>` were only stabilised in Rust 1.80. Some of these changes we could have done earlier, however.
## Summary
This PR refactors the formatter diff code to reuse the
`SourceKind::diff` logic. This has the benefit that the Notebook diff
now includes the cell numbers which was not present before.
## Test Plan
Update the snapshots and verified the cell numbers.
## Summary
Fixes#7853.
The old and new source files were reversed in the call to
`TextDiff::from_lines`, so the diff output of the CLI was also reversed.
## Test Plan
Two snapshots were updated in the process, so any reversal should be
caught :)
## Summary
This PR enables `ruff format` to format Jupyter notebooks.
Most of the work is contained in a new `format_source` method that
formats a generic `SourceKind`, then returns `Some(transformed)` if the
source required formatting, or `None` otherwise.
Closes https://github.com/astral-sh/ruff/issues/7598.
## Test Plan
Ran `cat foo.py | cargo run -p ruff_cli -- format --stdin-filename
Untitled.ipynb`; verified that the console showed a reasonable error:
```console
warning: Failed to read notebook Untitled.ipynb: Expected a Jupyter Notebook, which must be internally stored as JSON, but this file isn't valid JSON: EOF while parsing a value at line 1 column 0
```
Ran `cat Untitled.ipynb | cargo run -p ruff_cli -- format
--stdin-filename Untitled.ipynb`; verified that the JSON output
contained formatted source code.
## Summary
When writing back notebooks via `stdout`, we need to write back the
entire JSON content, not _just_ the fixed source code. Otherwise,
writing the output _back_ to the file will yield an invalid notebook.
Closes https://github.com/astral-sh/ruff/issues/7747
## Test Plan
`cargo test`
