## Summary
A new CLI option (`-o`/`--output-file`) to write output to a file
instead of stdout.
Major change is to remove the lock acquired on stdout. The argument is
that the output is buffered and thus the lock is acquired only when
writing a block (8kb). As per the benchmark below there is a slight
performance penalty.
Reference:
https://rustmagazine.org/issue-3/javascript-compiler/#printing-is-slow
## Benchmarks
_Output is truncated to only contain useful information:_
Command: `check --isolated --no-cache --select=ALL --show-source
./test-repos/cpython"`
Latest HEAD (361d45f2b2) with and without
the manual lock on stdout:
```console
Benchmark 1: With lock
Time (mean ± σ): 5.687 s ± 0.075 s [User: 17.110 s, System: 0.486 s]
Range (min … max): 5.615 s … 5.860 s 10 runs
Benchmark 2: Without lock
Time (mean ± σ): 5.719 s ± 0.064 s [User: 17.095 s, System: 0.491 s]
Range (min … max): 5.640 s … 5.865 s 10 runs
Summary
(1) ran 1.01 ± 0.02 times faster than (2)
```
This PR:
```console
Benchmark 1: This PR
Time (mean ± σ): 5.855 s ± 0.058 s [User: 17.197 s, System: 0.491 s]
Range (min … max): 5.786 s … 5.987 s 10 runs
Benchmark 2: Latest HEAD with lock
Time (mean ± σ): 5.645 s ± 0.033 s [User: 16.922 s, System: 0.495 s]
Range (min … max): 5.600 s … 5.712 s 10 runs
Summary
(2) ran 1.04 ± 0.01 times faster than (1)
```
## Test Plan
Run all of the commands which gives output with and without the
`--output-file=ruff.out` option:
* `--show-settings`
* `--show-files`
* `--show-fixes`
* `--diff`
* `--select=ALL`
* `--select=All --show-source`
* `--watch` (only stdout allowed)
resolves: #4754
## Summary
This adds a new subcommand that can be used as
```shell
cargo build --bin ruff_dev --profile=release-debug
perf record -g -F 999 target/release-debug/ruff_dev repeat --repeat 30 --exit-zero --no-cache path/to/cpython > /dev/null
flamegraph --perfdata perf.data
```
## Test Plan
This is a ruff internal script. I successfully used it to profile
cpython with the instructions above
* Create dummy format CLI
* Hide format from clap, too
Missed that this is a separate option from `#[doc(hidden)]`
* Remove cargo feature and replace with warning
* No-alloc files parameter matching
* beta warning: warn -> warn_user_once
* Rephrase warning
* Add basic jupyter notebook support behind a feature flag
* Address review comments
* Rename in separate commit to make both git and clippy happy
* cfg(feature = "jupyter_notebook") another test
* Address more review comments
* Address more review comments
* and clippy and windows
* More review comment
For example:
$ ruff check --select=EM<Tab>
EM -- flake8-errmsg
EM10 EM1 --
EM101 -- raw-string-in-exception
EM102 -- f-string-in-exception
EM103 -- dot-format-in-exception
(You will need to enable autocompletion as described
in the Autocompletion section in the README.)
Fixes#2808.
(The --help help change in the README is due to a clap bug,
for which I already submitted a fix:
https://github.com/clap-rs/clap/pull/4710.)
The synopsis is as follows.
List all top-level config keys:
$ ruff config
allowed-confusables
builtins
cache-dir
... etc.
List all config keys in a specific section:
$ ruff config mccabe
max-complexity
Describe a specific config option:
$ ruff config mccabe.max-complexity
The maximum McCabe complexity to allow before triggering `C901` errors.
Default value: 10
Type: int
Example usage:
```toml
# Flag errors (`C901`) whenever the complexity level exceeds 5.
max-complexity = 5
```
The new `ruff rule` output format introduced in
551b810aeb doesn't print Markdown but
rather some rich text with escape sequences for colors and links,
it's actually the "text" format that prints Markdown, so naming the new
format "markdown" is very confusing. This commit therefore renames it to
"pretty".
This isn't a breaking change since there hasn't been a release yet.
Dhruv Manilawala
konstin
Charlie Marsh
Jonathan Plasse
Aaron Cunningham
Micha Reiser
Jeong YunWon
Martin Fischer
Nick Pope