scripts/migrate-black.py

   1 #!/usr/bin/env python3
   2 # check out every commit added by the current branch, blackify them,
   3 # and generate diffs to reconstruct the original commits, but then
   4 # blackified
   5 import logging
   6 import os
   7 import sys
   8 from subprocess import PIPE, Popen, check_output, run
   9
  10
  11 def git(*args: str) -> str:
  12     return check_output(["git"] + list(args)).decode("utf8").strip()
  13
  14
  15 def blackify(base_branch: str, black_command: str, logger: logging.Logger) -> int:
  16     current_branch = git("branch", "--show-current")
  17
  18     if not current_branch or base_branch == current_branch:
  19         logger.error("You need to check out a feature branch to work on")
  20         return 1
  21
  22     if not os.path.exists(".git"):
  23         logger.error("Run me in the root of your repo")
  24         return 1
  25
  26     merge_base = git("merge-base", "HEAD", base_branch)
  27     if not merge_base:
  28         logger.error(
  29             "Could not find a common commit for current head and %s" % base_branch
  30         )
  31         return 1
  32
  33     commits = git(
  34         "log", "--reverse", "--pretty=format:%H", "%s~1..HEAD" % merge_base
  35     ).split()
  36     for commit in commits:
  37         git("checkout", commit, "-b%s-black" % commit)
  38         check_output(black_command, shell=True)
  39         git("commit", "-aqm", "blackify")
  40
  41     git("checkout", base_branch, "-b%s-black" % current_branch)
  42
  43     for last_commit, commit in zip(commits, commits[1:]):
  44         allow_empty = (
  45             b"--allow-empty" in run(["git", "apply", "-h"], stdout=PIPE).stdout
  46         )
  47         quiet = b"--quiet" in run(["git", "apply", "-h"], stdout=PIPE).stdout
  48         git_diff = Popen(
  49             [
  50                 "git",
  51                 "diff",
  52                 "--find-copies",
  53                 "%s-black..%s-black" % (last_commit, commit),
  54             ],
  55             stdout=PIPE,
  56         )
  57         git_apply = Popen(
  58             [
  59                 "git",
  60                 "apply",
  61             ]
  62             + (["--quiet"] if quiet else [])
  63             + [
  64                 "-3",
  65                 "--intent-to-add",
  66             ]
  67             + (["--allow-empty"] if allow_empty else [])
  68             + [
  69                 "-",
  70             ],
  71             stdin=git_diff.stdout,
  72         )
  73         if git_diff.stdout is not None:
  74             git_diff.stdout.close()
  75         git_apply.communicate()
  76         git("commit", "--allow-empty", "-aqC", commit)
  77
  78     for commit in commits:
  79         git("branch", "-qD", "%s-black" % commit)
  80
  81     return 0
  82
  83
  84 if __name__ == "__main__":
  85     import argparse
  86
  87     parser = argparse.ArgumentParser()
  88     parser.add_argument("base_branch")
  89     parser.add_argument("--black_command", default="black -q .")
  90     parser.add_argument("--logfile", type=argparse.FileType("w"), default=sys.stdout)
  91     args = parser.parse_args()
  92     logger = logging.getLogger(__name__)
  93     logger.addHandler(logging.StreamHandler(args.logfile))
  94     logger.setLevel(logging.INFO)
  95     sys.exit(blackify(args.base_branch, args.black_command, logger))