pre-commit/pre_commit/resources/hook-tmpl

#!/usr/bin/env python3
"""File generated by pre-commit: https://pre-commit.com"""
import distutils.spawn
import os
import subprocess
import sys
from typing import Callable
from typing import Dict
from typing import Tuple

# 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 = ''
HOOK_TYPE = ''
INSTALL_PYTHON = ''
SKIP_ON_MISSING_CONFIG = False
# end templated


class EarlyExit(RuntimeError):
    pass


class FatalError(RuntimeError):
    pass


def _norm_exe(exe: str) -> Tuple[str, ...]:
    """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()
        except UnicodeDecodeError:
            return ()

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


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

    if HOOK_TYPE == 'pre-push':
        stdin = sys.stdin.buffer.read()
    else:
        stdin = b''

    legacy_hook = os.path.join(HERE, f'{HOOK_TYPE}.legacy')
    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() -> None:
    cmd = ('git', 'rev-parse', '--show-toplevel')
    top_level = subprocess.check_output(cmd).decode().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(f'`{CONFIG}` config file not found. Skipping `pre-commit`.')
        raise EarlyExit()
    else:
        raise FatalError(
            f'No {CONFIG} file was found\n'
            f'- To temporarily silence this, run '
            f'`PRE_COMMIT_ALLOW_NO_CONFIG=1 git ...`\n'
            f'- To permanently silence this, install pre-commit with the '
            f'--allow-missing-config option\n'
            f'- To uninstall pre-commit run '
            f'`pre-commit uninstall`',
        )


def _exe() -> Tuple[str, ...]:
    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: str) -> bool:
    return not subprocess.call(('git', 'rev-list', '--quiet', rev))


def _pre_push(stdin: bytes) -> Tuple[str, ...]:
    remote_name = sys.argv[1]
    remote_url = sys.argv[2]

    opts: Tuple[str, ...] = ()
    for line in stdin.decode().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', f'--remotes={remote_name}',
            )).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:
                    rev_cmd = ('git', 'rev-parse', f'{first_ancestor}^')
                    source = subprocess.check_output(rev_cmd).decode().strip()
                    opts = ('--origin', local_sha, '--source', source)

    if opts:
        return (
            *opts, '--remote-name', remote_name, '--remote-url', remote_url,
        )
    else:
        # An attempt to push an empty changeset
        raise EarlyExit()


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


if sys.version_info < (3, 7):  # https://bugs.python.org/issue25942
    # this is the python 2.7 implementation
    def _subprocess_call(cmd: Tuple[str, ...]) -> int:
        return subprocess.Popen(cmd).wait()
else:
    _subprocess_call = subprocess.call


def main() -> int:
    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
    except KeyboardInterrupt:
        return 1


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