pre-commit/pre_commit/resources/hook-tmpl

#!/usr/bin/env python3
"""File generated by pre-commit: https://pre-commit.com"""
from __future__ import print_function

import distutils.spawn
import os
import subprocess
import sys

# work around https://github.com/Homebrew/homebrew-core/issues/30445
os.environ.pop('__PYVENV_LAUNCHER__', None)

HERE = os.path.dirname(os.path.abspath(__file__))
Z40 = '0' * 40
ID_HASH = '138fd403232d2ddd5efb44317e38bf03'
# start templated
CONFIG = None
HOOK_TYPE = None
INSTALL_PYTHON = None
SKIP_ON_MISSING_CONFIG = None
# end templated


class EarlyExit(RuntimeError):
    pass


class FatalError(RuntimeError):
    pass


def _norm_exe(exe):
    """Necessary for shebang support on windows.

    roughly lifted from `identify.identify.parse_shebang`
    """
    with open(exe, 'rb') as f:
        if f.read(2) != b'#!':
            return ()
        try:
            first_line = f.readline().decode('UTF-8')
        except UnicodeDecodeError:
            return ()

        cmd = first_line.split()
        if cmd[0] == '/usr/bin/env':
            del cmd[0]
        return tuple(cmd)


def _run_legacy():
    if __file__.endswith('.legacy'):
        raise SystemExit(
            "bug: pre-commit's script is installed in migration mode\n"
            'run `pre-commit install -f --hook-type {}` to fix this\n\n'
            'Please report this bug at '
            'https://github.com/pre-commit/pre-commit/issues'.format(
                HOOK_TYPE,
            ),
        )

    if HOOK_TYPE == 'pre-push':
        stdin = getattr(sys.stdin, 'buffer', sys.stdin).read()
    else:
        stdin = None

    legacy_hook = os.path.join(HERE, '{}.legacy'.format(HOOK_TYPE))
    if os.access(legacy_hook, os.X_OK):
        cmd = _norm_exe(legacy_hook) + (legacy_hook,) + tuple(sys.argv[1:])
        proc = subprocess.Popen(cmd, stdin=subprocess.PIPE if stdin else None)
        proc.communicate(stdin)
        return proc.returncode, stdin
    else:
        return 0, stdin


def _validate_config():
    cmd = ('git', 'rev-parse', '--show-toplevel')
    top_level = subprocess.check_output(cmd).decode('UTF-8').strip()
    cfg = os.path.join(top_level, CONFIG)
    if os.path.isfile(cfg):
        pass
    elif SKIP_ON_MISSING_CONFIG or os.getenv('PRE_COMMIT_ALLOW_NO_CONFIG'):
        print(
            '`{}` config file not found. '
            'Skipping `pre-commit`.'.format(CONFIG),
        )
        raise EarlyExit()
    else:
        raise FatalError(
            'No {} file was found\n'
            '- To temporarily silence this, run '
            '`PRE_COMMIT_ALLOW_NO_CONFIG=1 git ...`\n'
            '- To permanently silence this, install pre-commit with the '
            '--allow-missing-config option\n'
            '- To uninstall pre-commit run '
            '`pre-commit uninstall`'.format(CONFIG),
        )


def _exe():
    with open(os.devnull, 'wb') as devnull:
        for exe in (INSTALL_PYTHON, sys.executable):
            try:
                if not subprocess.call(
                        (exe, '-c', 'import pre_commit.main'),
                        stdout=devnull, stderr=devnull,
                ):
                    return (exe, '-m', 'pre_commit.main', 'run')
            except OSError:
                pass

    if distutils.spawn.find_executable('pre-commit'):
        return ('pre-commit', 'run')

    raise FatalError(
        '`pre-commit` not found.  Did you forget to activate your virtualenv?',
    )


def _rev_exists(rev):
    return not subprocess.call(('git', 'rev-list', '--quiet', rev))


def _pre_push(stdin):
    remote = sys.argv[1]

    opts = ()
    for line in stdin.decode('UTF-8').splitlines():
        _, local_sha, _, remote_sha = line.split()
        if local_sha == Z40:
            continue
        elif remote_sha != Z40 and _rev_exists(remote_sha):
            opts = ('--origin', local_sha, '--source', remote_sha)
        else:
            # ancestors not found in remote
            ancestors = subprocess.check_output((
                'git', 'rev-list', local_sha, '--topo-order', '--reverse',
                '--not', '--remotes={}'.format(remote),
            )).decode().strip()
            if not ancestors:
                continue
            else:
                first_ancestor = ancestors.splitlines()[0]
                cmd = ('git', 'rev-list', '--max-parents=0', local_sha)
                roots = set(subprocess.check_output(cmd).decode().splitlines())
                if first_ancestor in roots:
                    # pushing the whole tree including root commit
                    opts = ('--all-files',)
                else:
                    cmd = ('git', 'rev-parse', '{}^'.format(first_ancestor))
                    source = subprocess.check_output(cmd).decode().strip()
                    opts = ('--origin', local_sha, '--source', source)

    if opts:
        return opts
    else:
        # An attempt to push an empty changeset
        raise EarlyExit()


def _opts(stdin):
    fns = {
        'commit-msg': lambda _: ('--commit-msg-filename', sys.argv[1]),
        'pre-commit': lambda _: (),
        'pre-push': _pre_push,
    }
    stage = HOOK_TYPE.replace('pre-', '')
    return ('--config', CONFIG, '--hook-stage', stage) + fns[HOOK_TYPE](stdin)


def main():
    retv, stdin = _run_legacy()
    try:
        _validate_config()
        return retv | subprocess.call(_exe() + _opts(stdin))
    except EarlyExit:
        return retv
    except FatalError as e:
        print(e.args[0])
        return 1


if __name__ == '__main__':
    exit(main())