Files
pre-commit/pre_commit/util.py
2020-01-12 10:46:33 -08:00

265 lines
7.5 KiB
Python

import contextlib
import errno
import os.path
import shutil
import stat
import subprocess
import sys
import tempfile
from types import TracebackType
from typing import Any
from typing import Callable
from typing import Dict
from typing import Generator
from typing import IO
from typing import Optional
from typing import Tuple
from typing import Type
from typing import Union
from pre_commit import five
from pre_commit import parse_shebang
if sys.version_info >= (3, 7): # pragma: no cover (PY37+)
from importlib.resources import open_binary
from importlib.resources import read_text
else: # pragma: no cover (<PY37)
from importlib_resources import open_binary
from importlib_resources import read_text
EnvironT = Union[Dict[str, str], 'os._Environ']
def mkdirp(path: str) -> None:
try:
os.makedirs(path)
except OSError:
if not os.path.exists(path):
raise
@contextlib.contextmanager
def clean_path_on_failure(path: str) -> Generator[None, None, None]:
"""Cleans up the directory on an exceptional failure."""
try:
yield
except BaseException:
if os.path.exists(path):
rmtree(path)
raise
@contextlib.contextmanager
def noop_context() -> Generator[None, None, None]:
yield
@contextlib.contextmanager
def tmpdir() -> Generator[str, None, None]:
"""Contextmanager to create a temporary directory. It will be cleaned up
afterwards.
"""
tempdir = tempfile.mkdtemp()
try:
yield tempdir
finally:
rmtree(tempdir)
def resource_bytesio(filename: str) -> IO[bytes]:
return open_binary('pre_commit.resources', filename)
def resource_text(filename: str) -> str:
return read_text('pre_commit.resources', filename)
def make_executable(filename: str) -> None:
original_mode = os.stat(filename).st_mode
os.chmod(
filename, original_mode | stat.S_IXUSR | stat.S_IXGRP | stat.S_IXOTH,
)
class CalledProcessError(RuntimeError):
def __init__(
self,
returncode: int,
cmd: Tuple[str, ...],
expected_returncode: int,
stdout: bytes,
stderr: Optional[bytes],
) -> None:
super().__init__(returncode, cmd, expected_returncode, stdout, stderr)
self.returncode = returncode
self.cmd = cmd
self.expected_returncode = expected_returncode
self.stdout = stdout
self.stderr = stderr
def __bytes__(self) -> bytes:
def _indent_or_none(part: Optional[bytes]) -> bytes:
if part:
return b'\n ' + part.replace(b'\n', b'\n ')
else:
return b' (none)'
return b''.join((
'command: {!r}\n'
'return code: {}\n'
'expected return code: {}\n'.format(
self.cmd, self.returncode, self.expected_returncode,
).encode(),
b'stdout:', _indent_or_none(self.stdout), b'\n',
b'stderr:', _indent_or_none(self.stderr),
))
def __str__(self) -> str:
return self.__bytes__().decode()
def _cmd_kwargs(
*cmd: str,
**kwargs: Any,
) -> Tuple[Tuple[str, ...], Dict[str, Any]]:
# py2/py3 on windows are more strict about the types here
cmd = tuple(five.n(arg) for arg in cmd)
kwargs['env'] = {
five.n(key): five.n(value)
for key, value in kwargs.pop('env', {}).items()
} or None
for arg in ('stdin', 'stdout', 'stderr'):
kwargs.setdefault(arg, subprocess.PIPE)
return cmd, kwargs
def cmd_output_b(
*cmd: str,
**kwargs: Any,
) -> Tuple[int, bytes, Optional[bytes]]:
retcode = kwargs.pop('retcode', 0)
cmd, kwargs = _cmd_kwargs(*cmd, **kwargs)
try:
cmd = parse_shebang.normalize_cmd(cmd)
except parse_shebang.ExecutableNotFoundError as e:
returncode, stdout_b, stderr_b = e.to_output()
else:
proc = subprocess.Popen(cmd, **kwargs)
stdout_b, stderr_b = proc.communicate()
returncode = proc.returncode
if retcode is not None and retcode != returncode:
raise CalledProcessError(returncode, cmd, retcode, stdout_b, stderr_b)
return returncode, stdout_b, stderr_b
def cmd_output(*cmd: str, **kwargs: Any) -> Tuple[int, str, Optional[str]]:
returncode, stdout_b, stderr_b = cmd_output_b(*cmd, **kwargs)
stdout = stdout_b.decode() if stdout_b is not None else None
stderr = stderr_b.decode() if stderr_b is not None else None
return returncode, stdout, stderr
if os.name != 'nt': # pragma: windows no cover
from os import openpty
import termios
class Pty:
def __init__(self) -> None:
self.r: Optional[int] = None
self.w: Optional[int] = None
def __enter__(self) -> 'Pty':
self.r, self.w = openpty()
# tty flags normally change \n to \r\n
attrs = termios.tcgetattr(self.r)
assert isinstance(attrs[1], int)
attrs[1] &= ~(termios.ONLCR | termios.OPOST)
termios.tcsetattr(self.r, termios.TCSANOW, attrs)
return self
def close_w(self) -> None:
if self.w is not None:
os.close(self.w)
self.w = None
def close_r(self) -> None:
assert self.r is not None
os.close(self.r)
self.r = None
def __exit__(
self,
exc_type: Optional[Type[BaseException]],
exc_value: Optional[BaseException],
traceback: Optional[TracebackType],
) -> None:
self.close_w()
self.close_r()
def cmd_output_p(
*cmd: str,
**kwargs: Any,
) -> Tuple[int, bytes, Optional[bytes]]:
assert kwargs.pop('retcode') is None
assert kwargs['stderr'] == subprocess.STDOUT, kwargs['stderr']
cmd, kwargs = _cmd_kwargs(*cmd, **kwargs)
try:
cmd = parse_shebang.normalize_cmd(cmd)
except parse_shebang.ExecutableNotFoundError as e:
return e.to_output()
with open(os.devnull) as devnull, Pty() as pty:
assert pty.r is not None
kwargs.update({'stdin': devnull, 'stdout': pty.w, 'stderr': pty.w})
proc = subprocess.Popen(cmd, **kwargs)
pty.close_w()
buf = b''
while True:
try:
bts = os.read(pty.r, 4096)
except OSError as e:
if e.errno == errno.EIO:
bts = b''
else:
raise
else:
buf += bts
if not bts:
break
return proc.wait(), buf, None
else: # pragma: no cover
cmd_output_p = cmd_output_b
def rmtree(path: str) -> None:
"""On windows, rmtree fails for readonly dirs."""
def handle_remove_readonly(
func: Callable[..., Any],
path: str,
exc: Tuple[Type[OSError], OSError, TracebackType],
) -> None:
excvalue = exc[1]
if (
func in (os.rmdir, os.remove, os.unlink) and
excvalue.errno == errno.EACCES
):
for p in (path, os.path.dirname(path)):
os.chmod(p, os.stat(p).st_mode | stat.S_IWUSR)
func(path)
else:
raise
shutil.rmtree(path, ignore_errors=False, onerror=handle_remove_readonly)
def parse_version(s: str) -> Tuple[int, ...]:
"""poor man's version comparison"""
return tuple(int(p) for p in s.split('.'))