QuantumLibraries/Build/check_indents.py

#!/bin/env python
# -*- coding: utf-8 -*-
##
# check_indents.py: If a file has both space and tab indenting, returns an exit
#     code and normalizes \t to four spaces.
##
# Copyright (c) Microsoft Corporation. All rights reserved.
# Licensed under the MIT License.
##

import re
from typing import Tuple

def find_whitespace(string : str) -> Tuple[str, str]:
    groups = re.match(r'(\s*)([^\s].*$)?', string, flags=re.S).groups()
    return groups[0], groups[1] or ''

def check_file(filename : str) -> bool:
    """
    Checks a single file, returning True and writing a cleaned file if a mix
    of tabs and spaces was found.
    """
    problem_found = False
    found_spaces = False
    found_tabs = False

    with open(filename, 'r', encoding='utf-8') as f:
        contents = list(f.readlines())

    for line in contents:
        # Find the leading whitespace.
        whitespace, rest = find_whitespace(line)
        found_spaces = found_spaces or (' ' in whitespace)
        found_tabs = found_tabs or ('\t' in whitespace)

    problem_found = found_spaces and found_tabs

    if problem_found:
        print(f"Found mixed spaces and tabs in {filename}.")
        # Time to normalize!
        with open(filename, 'w', encoding='utf-8') as f:
            f.writelines(
                whitespace.replace('\t', '    ') + rest
                for whitespace, rest in map(find_whitespace, contents)
            )

    return problem_found

if __name__ == "__main__":
    import sys
    filenames = sys.argv[1:]
    exit_code = 0

    for filename in filenames:
        if check_file(filename):
            exit_code = -1

    sys.exit(exit_code)