Add support for tidy linting via external tools for non-rust files

This change adds the flag `--check-extras` to `tidy`. It accepts a comma
separated list of any of the options:

- py (test everything applicable for python files)
- py:lint (lint python files using `ruff`)
- py:fmt (check formatting for python files using `black`)
- shell or shell:lint (lint shell files using `shellcheck`)

Specific files to check can also be specified via positional args.
Examples:

- `./x test tidy --check-extras=shell,py`
- `./x test tidy --check-extras=py:fmt -- src/bootstrap/bootstrap.py`
- `./x test tidy --check-extras=shell -- src/ci/*.sh`
- Python formatting can be applied with bless:
  `./x test tidy --ckeck-extras=py:fmt --bless`

`ruff` and `black` need to be installed via pip; this tool manages these
within a virtual environment at `build/venv`. `shellcheck` needs to be
installed on the system already.

3 files changed, 7 insertions, 1 deletions

diff --git a/src/etc/completions/x.py.fish b/src/etc/completions/x.py.fish
index 238b5aa4d5a..40374e39cb5 100644
--- a/src/etc/completions/x.py.fish
+++ b/src/etc/completions/x.py.fish
@@ -227,6 +227,7 @@ complete -c x.py -n "__fish_seen_subcommand_from doc" -s h -l help -d 'Print hel
 complete -c x.py -n "__fish_seen_subcommand_from test" -l skip -d 'skips tests matching SUBSTRING, if supported by test tool. May be passed multiple times' -r
 complete -c x.py -n "__fish_seen_subcommand_from test" -l test-args -d 'extra arguments to be passed for the test tool being used (e.g. libtest, compiletest or rustdoc)' -r
 complete -c x.py -n "__fish_seen_subcommand_from test" -l rustc-args -d 'extra options to pass the compiler when running tests' -r
+complete -c x.py -n "__fish_seen_subcommand_from test" -l extra-checks -d 'comma-separated list of other files types to check (accepts py, py:lint, py:fmt, shell)' -r
 complete -c x.py -n "__fish_seen_subcommand_from test" -l compare-mode -d 'mode describing what file the actual ui output will be compared to' -r
 complete -c x.py -n "__fish_seen_subcommand_from test" -l pass -d 'force {check,build,run}-pass tests to this mode' -r
 complete -c x.py -n "__fish_seen_subcommand_from test" -l run -d 'whether to execute run-* tests' -r
diff --git a/src/etc/completions/x.py.ps1 b/src/etc/completions/x.py.ps1
index ff7d49d5e30..16b733632ec 100644
--- a/src/etc/completions/x.py.ps1
+++ b/src/etc/completions/x.py.ps1
@@ -299,6 +299,7 @@ Register-ArgumentCompleter -Native -CommandName 'x.py' -ScriptBlock {
             [CompletionResult]::new('--skip', 'skip', [CompletionResultType]::ParameterName, 'skips tests matching SUBSTRING, if supported by test tool. May be passed multiple times')
             [CompletionResult]::new('--test-args', 'test-args', [CompletionResultType]::ParameterName, 'extra arguments to be passed for the test tool being used (e.g. libtest, compiletest or rustdoc)')
             [CompletionResult]::new('--rustc-args', 'rustc-args', [CompletionResultType]::ParameterName, 'extra options to pass the compiler when running tests')
+            [CompletionResult]::new('--extra-checks', 'extra-checks', [CompletionResultType]::ParameterName, 'comma-separated list of other files types to check (accepts py, py:lint, py:fmt, shell)')
             [CompletionResult]::new('--compare-mode', 'compare-mode', [CompletionResultType]::ParameterName, 'mode describing what file the actual ui output will be compared to')
             [CompletionResult]::new('--pass', 'pass', [CompletionResultType]::ParameterName, 'force {check,build,run}-pass tests to this mode')
             [CompletionResult]::new('--run', 'run', [CompletionResultType]::ParameterName, 'whether to execute run-* tests')
diff --git a/src/etc/completions/x.py.sh b/src/etc/completions/x.py.sh
index 4e9286ae1e8..01727748f03 100644
--- a/src/etc/completions/x.py.sh
+++ b/src/etc/completions/x.py.sh
@@ -1569,7 +1569,7 @@ _x.py() {
             return 0
             ;;
         x.py__test)
-            opts="-v -i -j -h --no-fail-fast --skip --test-args --rustc-args --no-doc --doc --bless --force-rerun --only-modified --compare-mode --pass --run --rustfix-coverage --verbose --incremental --config --build-dir --build --host --target --exclude --include-default-paths --rustc-error-format --on-fail --dry-run --stage --keep-stage --keep-stage-std --src --jobs --warnings --error-format --json-output --color --llvm-skip-rebuild --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --reproducible-artifact --set --help [PATHS]... [ARGS]..."
+            opts="-v -i -j -h --no-fail-fast --skip --test-args --rustc-args --no-doc --doc --bless --extra-checks --force-rerun --only-modified --compare-mode --pass --run --rustfix-coverage --verbose --incremental --config --build-dir --build --host --target --exclude --include-default-paths --rustc-error-format --on-fail --dry-run --stage --keep-stage --keep-stage-std --src --jobs --warnings --error-format --json-output --color --llvm-skip-rebuild --rust-profile-generate --rust-profile-use --llvm-profile-use --llvm-profile-generate --reproducible-artifact --set --help [PATHS]... [ARGS]..."
             if [[ ${cur} == -* || ${COMP_CWORD} -eq 2 ]] ; then
                 COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
                 return 0
@@ -1587,6 +1587,10 @@ _x.py() {
                     COMPREPLY=($(compgen -f "${cur}"))
                     return 0
                     ;;
+                --extra-checks)
+                    COMPREPLY=($(compgen -f "${cur}"))
+                    return 0
+                    ;;
                 --compare-mode)
                     COMPREPLY=($(compgen -f "${cur}"))
                     return 0