def check_or_fix()

in scripts/readme_toc.py [0:0]

• 40 lines of code
• 12 McCabe index (conditional complexity)

def check_or_fix(readme_path: Path, fix: bool) -> int:
    if not readme_path.is_file():
        print(f"Error: file not found: {readme_path}", file=sys.stderr)
        return 1
    content = readme_path.read_text(encoding="utf-8")
    lines = content.splitlines()
    # locate ToC markers
    try:
        begin_idx = next(i for i, l in enumerate(lines) if l.strip() == BEGIN_TOC)
        end_idx = next(i for i, l in enumerate(lines) if l.strip() == END_TOC)
    except StopIteration:
        print(
            f"Error: Could not locate '{BEGIN_TOC}' or '{END_TOC}' in {readme_path}.",
            file=sys.stderr,
        )
        return 1
    # extract current ToC list items
    current_block = lines[begin_idx + 1 : end_idx]
    current = [l for l in current_block if l.lstrip().startswith("- [")]
    # generate expected ToC
    expected = generate_toc_lines(content)
    if current == expected:
        return 0
    if not fix:
        print(
            "ERROR: README ToC is out of date. Diff between existing and generated ToC:"
        )
        # Show full unified diff of current vs expected
        diff = difflib.unified_diff(
            current,
            expected,
            fromfile="existing ToC",
            tofile="generated ToC",
            lineterm="",
        )
        for line in diff:
            print(line)
        return 1
    # rebuild file with updated ToC
    prefix = lines[: begin_idx + 1]
    suffix = lines[end_idx:]
    new_lines = prefix + [""] + expected + [""] + suffix
    readme_path.write_text("\n".join(new_lines) + "\n", encoding="utf-8")
    print(f"Updated ToC in {readme_path}.")
    return 0