This shrinks a good bit more than previously, which was helpful for all
the formatter bugs. fwiw i treat this as a very ad-hoc script since it's
mainly my ecosystem bug processing companion.
## Summary
It can happen that we can't read a file (a python file, a jupyter
notebook or pyproject.toml), which needs to be handled and handled
consistently for all file types. Instead of using `Err` or `error!`, we
emit E602 with the io error as message and continue. This PR makes sure
we handle all three cases consistently, emit E602.
I'm not convinced that it should be possible to disable io errors, but
we now handle the regular case consistently and at least print warning
consistently.
I went with `warn!` but i can change them all to `error!`, too.
It also checks the error case when a pyproject.toml is not readable. The
error message is not very helpful, but it's now a bit clearer that
actually ruff itself failed instead vs this being a diagnostic.
## Examples
This is how an Err of `run` looks now:

With an unreadable file and `IOError` disabled:

(we lint zero files but count files before linting not during so we exit
0)
I'm not sure if it should (or if we should take a different path with
manual ExitStatus), but this currently also triggers when `files` is
empty:

## Test Plan
Unix only: Create a temporary directory with files with permissions
`000` (not readable by the owner) and run on that directory. Since this
breaks the assumptions of most of the test code (single file, `ruff`
instead of `ruff_cli`), the test code is rather cumbersome and looks a
bit misplaced; i'm happy about suggestions to fit it in closer with the
other tests or streamline it in other ways. I added another test for
when the entire directory is not readable.
## Summary
For formatter instabilities, the message we get look something like
this:
```text
Unstable formatting /home/konsti/ruff/target/checkouts/deepmodeling:dpdispatcher/dpdispatcher/slurm.py
@@ -47,9 +47,9 @@
- script_header_dict["slurm_partition_line"] = (
- NOT_YET_IMPLEMENTED_ExprJoinedStr
- )
+ script_header_dict[
+ "slurm_partition_line"
+ ] = NOT_YET_IMPLEMENTED_ExprJoinedStr
Unstable formatting /home/konsti/ruff/target/checkouts/deepmodeling:dpdispatcher/dpdispatcher/pbs.py
@@ -26,9 +26,9 @@
- pbs_script_header_dict["select_node_line"] += (
- NOT_YET_IMPLEMENTED_ExprJoinedStr
- )
+ pbs_script_header_dict[
+ "select_node_line"
+ ] += NOT_YET_IMPLEMENTED_ExprJoinedStr
```
For ruff crashes. you don't even get that but just the file that crashed
it. To extract the actual bug, you'd need to manually remove parts of
the file, rerun to see if the bug still occurs (and revert if it
doesn't) until you have a minimal example.
With this script, you run
```shell
cargo run --bin ruff_shrinking -- target/checkouts/deepmodeling:dpdispatcher/dpdispatcher/slurm.py target/minirepo/code.py "Unstable formatting" "target/debug/ruff_dev format-dev --stability-check target/minirepo"
```
and get
```python
class Slurm():
def gen_script_header(self, job):
if resources.queue_name != "":
script_header_dict["slurm_partition_line"] = f"#SBATCH --partition {resources.queue_name}"
```
which is an nice minimal example.
I've been using this script and it would be easier for me if this were
part of main. The main disadvantage to merging is that it adds
additional dependencies.
## Test Plan
I've been using this for a number of minimization. This is an internal
helper script you only run manually. I could add a test that minimizes a
rule violation if required.
---------
Co-authored-by: Micha Reiser <micha@reiser.io>