chore: import upstream snapshot with attribution

scripts/pre-commit/whitespace.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+"""Trailing-whitespace and end-of-file normalisation, driven by Task.
+
+Replaces the end-of-file-fixer / trailing-whitespace pre-commit hooks, which
+have no read-only mode. Run via `task pre-commit` (check) and `task
+pre-commit:fix`.
+
+Takes git pathspecs (not a file list) and runs `git ls-files` itself, so the
+matched files never hit the command line - on Windows that list can be ~66KB
+and exceed the ~32KB CreateProcess argv limit.
+
+    python whitespace.py <pathspec>...          # check: report, exit 1 if any need fixing
+    python whitespace.py --fix <pathspec>...     # fix: rewrite in place
+
+Operates on bytes and only ever touches trailing spaces/tabs and the final
+newline, so it never mangles content or line endings. Binary files (those with
+a NUL byte) are skipped.
+"""
+
+from __future__ import annotations
+
+import subprocess
+import sys
+from pathlib import Path
+
+
+def tracked_files(pathspecs: list[str]) -> list[str]:
+    result = subprocess.run(
+        ["git", "ls-files", "-z", *pathspecs],
+        check=True,
+        capture_output=True,
+        text=True,
+    )
+    return [path for path in result.stdout.split("\0") if path]
+
+
+def normalise(data: bytes) -> bytes:
+    # Strip trailing spaces/tabs from each line (leave \r so CRLF survives).
+    lines = [line.rstrip(b" \t") for line in data.split(b"\n")]
+    body = b"\n".join(lines)
+    # Ensure a non-empty file ends with exactly one newline.
+    stripped = body.rstrip(b"\r\n")
+    return stripped + b"\n" if stripped else body
+
+
+def main() -> int:
+    args = sys.argv[1:]
+    fix = "--fix" in args
+    pathspecs = [a for a in args if a != "--fix"]
+
+    offenders: list[str] = []
+    for path in tracked_files(pathspecs):
+        data = Path(path).read_bytes()
+        if b"\0" in data:
+            continue
+        fixed = normalise(data)
+        if fixed == data:
+            continue
+        offenders.append(path)
+        if fix:
+            Path(path).write_bytes(fixed)
+
+    if offenders and not fix:
+        print(f"{len(offenders)} file(s) need whitespace fixing:")
+        for path in offenders:
+            print(f"  {path}")
+        return 1
+    if offenders and fix:
+        print(f"Fixed whitespace in {len(offenders)} file(s).")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())