[ci] Sync pre-commit revs and prek version from requirements files (#19026)

Co-authored-by: pre-commit-ci-lite[bot] <117423508+pre-commit-ci-lite[bot]@users.noreply.github.com>

script/sync_dependency_versions.py

@@ -0,0 +1,164 @@
+#!/usr/bin/env python3
+"""Keep pre-commit hook revs in sync with the requirements files.
+
+Dependabot only bumps the ``package==version`` pins in ``requirements*.txt``.
+Some of those tools are pinned a second time as hook ``rev`` values in
+``.pre-commit-config.yaml``. This script treats the requirements files as
+the source of truth and rewrites the revs to match, editing the config
+through yamlrocks so comments and layout survive.
+
+Run without arguments to apply the changes in place, or with ``--check`` to
+only report drift (exit status 1 when anything is out of sync).
+"""
+
+from __future__ import annotations
+
+import argparse
+from dataclasses import dataclass
+from pathlib import Path
+import re
+import sys
+from typing import Any
+
+import yamlrocks
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+PRECOMMIT_CONFIG = ".pre-commit-config.yaml"
+
+
+class SyncError(Exception):
+    """A pin could not be located in a requirements file or the config."""
+
+
+@dataclass(frozen=True)
+class SyncTarget:
+    """A requirements pin and the pre-commit repo whose rev mirrors it."""
+
+    package: str
+    requirements_file: str
+    repo: str
+
+
+SYNC_TARGETS: tuple[SyncTarget, ...] = (
+    SyncTarget(
+        "ruff", "requirements_test.txt", "https://github.com/astral-sh/ruff-pre-commit"
+    ),
+    SyncTarget("flake8", "requirements_test.txt", "https://github.com/PyCQA/flake8"),
+    SyncTarget(
+        "pyupgrade", "requirements_test.txt", "https://github.com/asottile/pyupgrade"
+    ),
+    SyncTarget(
+        "clang-format",
+        "requirements_dev.txt",
+        "https://github.com/pre-commit/mirrors-clang-format",
+    ),
+    SyncTarget(
+        "yamllint",
+        "requirements_dev.txt",
+        "https://github.com/adrienverge/yamllint.git",
+    ),
+)
+
+
+def read_requirement_version(requirements: str, package: str) -> str | None:
+    """Return the ``==`` pin for ``package`` or None when it is not pinned."""
+    pattern = re.compile(
+        rf"^{re.escape(package)}==(?P<version>[^\s#]+)",
+        re.MULTILINE | re.IGNORECASE,
+    )
+    match = pattern.search(requirements)
+    return match.group("version") if match else None
+
+
+def find_repo_entry(doc: Any, repo: str) -> Any:
+    """Return the single ``- repo:`` block for ``repo`` in a pre-commit doc."""
+    try:
+        entries = [entry for entry in doc["repos"] if entry["repo"] == repo]
+    except KeyError as err:
+        raise SyncError(f"malformed pre-commit config, missing key {err}") from None
+    if len(entries) != 1:
+        raise SyncError(
+            f"expected exactly one block for repo {repo}, found {len(entries)}"
+        )
+    return entries[0]
+
+
+def current_rev(entry: Any, repo: str) -> tuple[str, str]:
+    """Split the block's rev into its tag prefix (``v`` or empty) and version."""
+    if "rev" not in entry:
+        raise SyncError(f"repo {repo} has no rev")
+    rev = entry["rev"]
+    if not isinstance(rev, str):
+        # A rev such as ``1.0`` parses as a number and cannot be compared or
+        # rewritten safely; quote it in the config instead.
+        raise SyncError(f"rev of repo {repo} is not a string: {rev!r}")
+    prefix = "v" if rev.startswith("v") else ""
+    return prefix, rev.removeprefix("v")
+
+
+def sync(root: Path, *, write: bool) -> list[str]:
+    """Bring every hook rev in line with its requirements pin.
+
+    Returns one description per rev that was (or, when ``write`` is False,
+    would be) changed. Raises SyncError when a pin cannot be found, which
+    means SYNC_TARGETS has gone stale and needs updating by hand.
+    """
+    config_path = root / PRECOMMIT_CONFIG
+    doc = yamlrocks.loads(config_path.read_bytes(), option=yamlrocks.OPT_ROUND_TRIP)
+    requirements: dict[str, str] = {}
+    changes: list[str] = []
+    for target in SYNC_TARGETS:
+        if target.requirements_file not in requirements:
+            requirements[target.requirements_file] = (
+                root / target.requirements_file
+            ).read_text()
+        version = read_requirement_version(
+            requirements[target.requirements_file], target.package
+        )
+        if version is None:
+            raise SyncError(
+                f"{target.requirements_file}: no '{target.package}==' pin found"
+            )
+
+        entry = find_repo_entry(doc, target.repo)
+        prefix, current = current_rev(entry, target.repo)
+        if current == version:
+            continue
+        changes.append(f"{target.package}: {current} -> {version}")
+        entry["rev"] = f"{prefix}{version}"
+
+    if changes and write:
+        config_path.write_bytes(doc.to_yaml())
+    return changes
+
+
+def main(argv: list[str] | None = None) -> int:
+    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
+    parser.add_argument(
+        "--check",
+        action="store_true",
+        help="report drift without modifying any file; exit 1 if out of sync",
+    )
+    parser.add_argument(
+        "--root",
+        type=Path,
+        default=REPO_ROOT,
+        help="repository checkout to operate on (default: this checkout)",
+    )
+    args = parser.parse_args(argv)
+
+    try:
+        changes = sync(args.root, write=not args.check)
+    except SyncError as err:
+        print(f"error: {err}", file=sys.stderr)
+        return 1
+
+    for change in changes:
+        print(change)
+    if args.check and changes:
+        return 1
+    return 0
+
+
+if __name__ == "__main__":  # pragma: no cover
+    sys.exit(main())