[py] Improve ruff linting DX and CI speed (#17588)

- Unify ruff_check.py + ruff_format.py into a single ruff.py that
  accepts check/format/both modes; eliminates duplicated dirs, excludes,
  and config references. Adds //py:ruff target for running both at once.
- Fix --exit-non-zero-on-fix footgun: ruff_check now exits 0 when all
  issues are auto-fixed. CI verification mode uses --no-fix explicitly.
- Add ruff check to scripts/format.sh (always, not just with --lint),
  resolving the ruff binary once via --run_under=echo to halve Bazel
  startup overhead. Auto-fixable lint issues are now committed by the
  CI bot alongside formatting fixes.
- Update py:lint to use --no-fix (pure verification, no side effects).
- Split ci-python.yml lint job into parallel lint-ruff / lint-mypy /
  lint-docs jobs so mypy does not block ruff feedback.

Author: AutomatedTester

.github/workflows/ci-python.yml

@@ -16,12 +16,29 @@ jobs:
       run: |
         bazel build //py:selenium-wheel //py:selenium-sdist
 
-  lint:
-    name: Lint
+  lint-ruff:
+    name: Lint (ruff)
     uses: ./.github/workflows/bazel.yml
     with:
-      name: Lint
-      run: ./go py:lint
+      name: Lint (ruff)
+      run: bazel run //py:ruff-check -- --no-fix
+
+  lint-mypy:
+    name: Lint (mypy)
+    uses: ./.github/workflows/bazel.yml
+    with:
+      name: Lint (mypy)
+      run: bazel run //py:mypy
+
+  lint-docs:
+    name: Lint (docs)
+    uses: ./.github/workflows/bazel.yml
+    with:
+      name: Lint (docs)
+      run: |
+        bazel run //py:generate-api-listing
+        bazel run //py:sphinx-autogen
+        bazel build //py:docs
 
   unit-tests:
     name: Unit Tests

py/BUILD.bazel

@@ -947,6 +947,11 @@ py_binary(
     ],
 )
 
+alias(
+    name = "ruff",
+    actual = "//py/private:ruff",
+)
+
 alias(
     name = "ruff-check",
     actual = "//py/private:ruff_check",

py/private/BUILD.bazel

@@ -22,24 +22,39 @@ py_binary(
     visibility = ["//visibility:public"],
 )
 
+py_binary(
+    name = "ruff",
+    srcs = ["ruff.py"],
+    data = [
+        "//py:pyproject.toml",
+        "@multitool//tools/ruff",
+    ],
+    visibility = ["//visibility:public"],
+    deps = ["@rules_python//python/runfiles"],
+)
+
 py_binary(
     name = "ruff_check",
-    srcs = ["ruff_check.py"],
+    srcs = ["ruff.py"],
+    args = ["check"],
     data = [
         "//py:pyproject.toml",
         "@multitool//tools/ruff",
     ],
+    main = "ruff.py",
     visibility = ["//visibility:public"],
     deps = ["@rules_python//python/runfiles"],
 )
 
 py_binary(
     name = "ruff_format",
-    srcs = ["ruff_format.py"],
+    srcs = ["ruff.py"],
+    args = ["format"],
     data = [
         "//py:pyproject.toml",
         "@multitool//tools/ruff",
     ],
+    main = "ruff.py",
     visibility = ["//visibility:public"],
     deps = ["@rules_python//python/runfiles"],
 )

py/private/ruff_format.py py/private/ruff.pypy/private/ruff_format.py renamed to py/private/ruff.py

@@ -15,10 +15,17 @@
 # specific language governing permissions and limitations
 # under the License.
 
-"""Run ruff format on Python files across the project.
+"""Run ruff check and/or format on Python files across the project.
+
+Mode is the first positional argument; remaining args are forwarded to ruff:
+    check   -- ruff check --fix --show-fixes (pass --no-fix for CI verify mode)
+    format  -- ruff format
+    both    -- check then format (default when no mode given)
 
 Usage:
+    bazel run //py:ruff-check -- [ruff check args]
     bazel run //py:ruff-format -- [ruff format args]
+    bazel run //py:ruff -- [ruff check+format args]
 """
 
 import os
@@ -31,8 +38,12 @@
 EXCLUDES = ["**/node_modules/**", "**/.bundle/**", "**/bidi/**", "**/devtools/**"]
 
 
+def run_check(ruff, exclude_args, dirs, extra_args):
+    cmd = [ruff, "check", "--fix", "--show-fixes", "--config=py/pyproject.toml"]
+    return subprocess.run(cmd + exclude_args + dirs + extra_args).returncode
+
+
 def run_format(ruff, exclude_args, dirs, extra_args):
-    """Run ruff format."""
     cmd = [ruff, "format", "--config=py/pyproject.toml"]
     return subprocess.run(cmd + exclude_args + dirs + extra_args).returncode
 
@@ -47,4 +58,17 @@ def run_format(ruff, exclude_args, dirs, extra_args):
     for pattern in EXCLUDES:
         exclude_args.extend(["--exclude", pattern])
 
-    sys.exit(run_format(ruff, exclude_args, ALL_DIRS, sys.argv[1:]))
+    mode = "both"
+    extra_args = sys.argv[1:]
+    if extra_args and extra_args[0] in ("check", "format", "both"):
+        mode = extra_args[0]
+        extra_args = extra_args[1:]
+
+    if mode == "check":
+        sys.exit(run_check(ruff, exclude_args, ALL_DIRS, extra_args))
+    elif mode == "format":
+        sys.exit(run_format(ruff, exclude_args, ALL_DIRS, extra_args))
+    else:
+        rc_check = run_check(ruff, exclude_args, ALL_DIRS, extra_args)
+        rc_format = run_format(ruff, exclude_args, ALL_DIRS, extra_args)
+        sys.exit(max(rc_check, rc_format))

py/private/ruff_check.py

@@ -170,10 +170,10 @@ task :format do
   Bazel.execute('run', [], '//py:ruff-format')
 end
 
-desc 'Run Python linters (ruff check, mypy, docs)'
+desc 'Run Python linters (ruff check --no-fix, mypy, docs)'
 task :lint do
-  puts '  Running ruff check...'
-  Bazel.execute('run', [], '//py:ruff-check')
+  puts '  Running ruff check (verify)...'
+  Bazel.execute('run', [], '//py:ruff-check', '--', '--no-fix')
   puts '  Running mypy...'
   Bazel.execute('run', [], '//py:mypy')
   Rake::Task['py:docs_generate'].invoke

rake_tasks/python.rake

@@ -119,12 +119,13 @@ fi
 
 if changed_matches '^py/'; then
     section "Python"
-    if [[ "$run_lint" == "true" ]]; then
-        echo "    ruff check" >&2
-        bazel run //py:ruff-check
-    fi
+    RUFF="$(bazel run --run_under=echo @multitool//tools/ruff)"
+    RUFF_COMMON=(--config=py/pyproject.toml --exclude '**/node_modules/**' --exclude '**/.bundle/**' --exclude '**/bidi/**' --exclude '**/devtools/**' py scripts common dotnet java javascript rb)
+    echo "    ruff check" >&2
+    # Apply auto-fixable lint issues; don't fail on unfixable violations (caught by py:lint)
+    "$RUFF" check --fix --show-fixes "${RUFF_COMMON[@]}" || true
     echo "    ruff format" >&2
-    bazel run //py:ruff-format
+    "$RUFF" format "${RUFF_COMMON[@]}"
 fi
 
 if changed_matches '^dotnet/'; then