pre-commit: Only run codespell check on changed lines

1 files changed, 94 insertions, 0 deletions

diff --git a/tools/codespell.py b/tools/codespell.py
new file mode 100755
index 0000000000..042bbf4921
--- /dev/null
+++ b/tools/codespell.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+import argparse
+import itertools
+import logging
+import os
+import subprocess
+import sys
+import typing
+
+import githelper
+
+
+def run_codespell_on_lines(rootdir, filename, lines, codespell_args):
+    """
+    Run codespell on the requested lines.
+
+    Returns 1 if any changes were made, else 0.
+    """
+    logger = logging.getLogger(__name__)
+    cmd = ["codespell", *codespell_args, "--", filename]
+    logger.debug("Running command: %r", cmd)
+
+    try:
+        subprocess.check_output(cmd)
+    except subprocess.CalledProcessError as e:
+        output = e.output.decode().strip()
+    else:
+        return 0
+
+    result = 0
+    for line in output.splitlines():
+        matched_fname_with_line = line.partition(": ")[0]
+        matched_fname, _, linenum = matched_fname_with_line.rpartition(":")
+        assert matched_fname == filename
+        if int(linenum) in lines:
+            result = 1
+            print(line)
+
+    return result
+
+
+def main(argv: typing.Optional[typing.List[str]] = None) -> int:
+    parser = argparse.ArgumentParser()
+    parser.add_argument("--from-ref", help="use changes changes since commit")
+    parser.add_argument("--to-ref", help="use changes until commit")
+    parser.add_argument("--files", nargs="*", help="only check these files")
+    parser.add_argument(
+        "-v", "--verbose", action="store_true", help="Be verbose"
+    )
+    args, codespell_args = parser.parse_known_args(argv)
+
+    logging.basicConfig(
+        format="[%(levelname)s] %(message)s",
+        level=logging.DEBUG if args.verbose else logging.INFO,
+    )
+
+    if not args.from_ref:
+        args.from_ref = os.getenv("PRE_COMMIT_FROM_REF") or os.getenv(
+            "PRE_COMMIT_SOURCE"
+        )
+
+    if not args.to_ref:
+        args.to_ref = os.getenv("PRE_COMMIT_TO_REF") or os.getenv(
+            "PRE_COMMIT_ORIGIN"
+        )
+
+    # Filter filenames
+    rootdir = githelper.get_toplevel_path()
+
+    files_with_added_lines = githelper.get_changed_lines(
+        from_ref=args.from_ref,
+        to_ref=args.to_ref,
+        filter_lines=lambda line: line.added,
+        include_files=args.files,
+    )
+
+    result = 0
+    for filename, file_lines in itertools.groupby(
+        files_with_added_lines, key=lambda line: line.sourcefile
+    ):
+        lines = set(line.number for line in file_lines)
+        result |= run_codespell_on_lines(
+            rootdir,
+            filename,
+            lines,
+            [arg for arg in codespell_args if arg != "--"],
+        )
+
+    return result
+
+
+if __name__ == "__main__":
+    sys.exit(main())