1"""isort.py. 2 3Defines a git hook to allow pre-commit warnings and errors about import order. 4 5usage: 6 exit_code = git_hook(strict=True) 7 8Copyright (C) 2015 Helen Sherwood-Taylor 9 10Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated 11documentation files (the "Software"), to deal in the Software without restriction, including without limitation 12the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and 13to permit persons to whom the Software is furnished to do so, subject to the following conditions: 14 15The above copyright notice and this permission notice shall be included in all copies or 16substantial portions of the Software. 17 18THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED 19TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 21CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 22OTHER DEALINGS IN THE SOFTWARE. 23 24""" 25import subprocess 26 27from isort import SortImports 28 29 30def get_output(command): 31 """ 32 Run a command and return raw output 33 34 :param str command: the command to run 35 :returns: the stdout output of the command 36 """ 37 return subprocess.check_output(command.split()) 38 39 40def get_lines(command): 41 """ 42 Run a command and return lines of output 43 44 :param str command: the command to run 45 :returns: list of whitespace-stripped lines output by command 46 """ 47 stdout = get_output(command) 48 return [line.strip().decode('utf-8') for line in stdout.splitlines()] 49 50 51def git_hook(strict=False): 52 """ 53 Git pre-commit hook to check staged files for isort errors 54 55 :param bool strict - if True, return number of errors on exit, 56 causing the hook to fail. If False, return zero so it will 57 just act as a warning. 58 59 :return number of errors if in strict mode, 0 otherwise. 60 """ 61 62 # Get list of files modified and staged 63 diff_cmd = "git diff-index --cached --name-only --diff-filter=ACMRTUXB HEAD" 64 files_modified = get_lines(diff_cmd) 65 66 errors = 0 67 for filename in files_modified: 68 if filename.endswith('.py'): 69 # Get the staged contents of the file 70 staged_cmd = "git show :%s" % filename 71 staged_contents = get_output(staged_cmd) 72 73 sort = SortImports( 74 file_path=filename, 75 file_contents=staged_contents.decode(), 76 check=True 77 ) 78 79 if sort.incorrectly_sorted: 80 errors += 1 81 82 return errors if strict else 0 83