Adding upstream version 2.2.0.

Signed-off-by: Daniel Baumann <daniel@debian.org>

pre_commit/languages/python.py

@@ -0,0 +1,210 @@
+import contextlib
+import functools
+import os
+import sys
+from typing import Callable
+from typing import ContextManager
+from typing import Generator
+from typing import Optional
+from typing import Sequence
+from typing import Tuple
+
+import pre_commit.constants as C
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import PatchesT
+from pre_commit.envcontext import UNSET
+from pre_commit.envcontext import Var
+from pre_commit.hook import Hook
+from pre_commit.languages import helpers
+from pre_commit.parse_shebang import find_executable
+from pre_commit.prefix import Prefix
+from pre_commit.util import CalledProcessError
+from pre_commit.util import clean_path_on_failure
+from pre_commit.util import cmd_output
+from pre_commit.util import cmd_output_b
+
+ENVIRONMENT_DIR = 'py_env'
+
+
+def bin_dir(venv: str) -> str:
+    """On windows there's a different directory for the virtualenv"""
+    bin_part = 'Scripts' if os.name == 'nt' else 'bin'
+    return os.path.join(venv, bin_part)
+
+
+def get_env_patch(venv: str) -> PatchesT:
+    return (
+        ('PYTHONHOME', UNSET),
+        ('VIRTUAL_ENV', venv),
+        ('PATH', (bin_dir(venv), os.pathsep, Var('PATH'))),
+    )
+
+
+def _find_by_py_launcher(
+        version: str,
+) -> Optional[str]:  # pragma: no cover (windows only)
+    if version.startswith('python'):
+        num = version[len('python'):]
+        try:
+            cmd = ('py', f'-{num}', '-c', 'import sys; print(sys.executable)')
+            return cmd_output(*cmd)[1].strip()
+        except CalledProcessError:
+            pass
+    return None
+
+
+def _find_by_sys_executable() -> Optional[str]:
+    def _norm(path: str) -> Optional[str]:
+        _, exe = os.path.split(path.lower())
+        exe, _, _ = exe.partition('.exe')
+        if exe not in {'python', 'pythonw'} and find_executable(exe):
+            return exe
+        return None
+
+    # On linux, I see these common sys.executables:
+    #
+    # system `python`: /usr/bin/python -> python2.7
+    # system `python2`: /usr/bin/python2 -> python2.7
+    # virtualenv v: v/bin/python (will not return from this loop)
+    # virtualenv v -ppython2: v/bin/python -> python2
+    # virtualenv v -ppython2.7: v/bin/python -> python2.7
+    # virtualenv v -ppypy: v/bin/python -> v/bin/pypy
+    for path in (sys.executable, os.path.realpath(sys.executable)):
+        exe = _norm(path)
+        if exe:
+            return exe
+    return None
+
+
+@functools.lru_cache(maxsize=1)
+def get_default_version() -> str:  # pragma: no cover (platform dependent)
+    # First attempt from `sys.executable` (or the realpath)
+    exe = _find_by_sys_executable()
+    if exe:
+        return exe
+
+    # Next try the `pythonX.X` executable
+    exe = f'python{sys.version_info[0]}.{sys.version_info[1]}'
+    if find_executable(exe):
+        return exe
+
+    if _find_by_py_launcher(exe):
+        return exe
+
+    # Give a best-effort try for windows
+    default_folder_name = exe.replace('.', '')
+    if os.path.exists(fr'C:\{default_folder_name}\python.exe'):
+        return exe
+
+    # We tried!
+    return C.DEFAULT
+
+
+def _sys_executable_matches(version: str) -> bool:
+    if version == 'python':
+        return True
+    elif not version.startswith('python'):
+        return False
+
+    try:
+        info = tuple(int(p) for p in version[len('python'):].split('.'))
+    except ValueError:
+        return False
+
+    return sys.version_info[:len(info)] == info
+
+
+def norm_version(version: str) -> str:
+    # first see if our current executable is appropriate
+    if _sys_executable_matches(version):
+        return sys.executable
+
+    if os.name == 'nt':  # pragma: no cover (windows)
+        version_exec = _find_by_py_launcher(version)
+        if version_exec:
+            return version_exec
+
+        # Try looking up by name
+        version_exec = find_executable(version)
+        if version_exec and version_exec != version:
+            return version_exec
+
+        # If it is in the form pythonx.x search in the default
+        # place on windows
+        if version.startswith('python'):
+            default_folder_name = version.replace('.', '')
+            return fr'C:\{default_folder_name}\python.exe'
+
+    # Otherwise assume it is a path
+    return os.path.expanduser(version)
+
+
+def py_interface(
+        _dir: str,
+        _make_venv: Callable[[str, str], None],
+) -> Tuple[
+    Callable[[Prefix, str], ContextManager[None]],
+    Callable[[Prefix, str], bool],
+    Callable[[Hook, Sequence[str], bool], Tuple[int, bytes]],
+    Callable[[Prefix, str, Sequence[str]], None],
+]:
+    @contextlib.contextmanager
+    def in_env(
+            prefix: Prefix,
+            language_version: str,
+    ) -> Generator[None, None, None]:
+        envdir = prefix.path(helpers.environment_dir(_dir, language_version))
+        with envcontext(get_env_patch(envdir)):
+            yield
+
+    def healthy(prefix: Prefix, language_version: str) -> bool:
+        envdir = helpers.environment_dir(_dir, language_version)
+        exe_name = 'python.exe' if sys.platform == 'win32' else 'python'
+        py_exe = prefix.path(bin_dir(envdir), exe_name)
+        with in_env(prefix, language_version):
+            retcode, _, _ = cmd_output_b(
+                py_exe, '-c', 'import ctypes, datetime, io, os, ssl, weakref',
+                cwd='/',
+                retcode=None,
+            )
+        return retcode == 0
+
+    def run_hook(
+            hook: Hook,
+            file_args: Sequence[str],
+            color: bool,
+    ) -> Tuple[int, bytes]:
+        with in_env(hook.prefix, hook.language_version):
+            return helpers.run_xargs(hook, hook.cmd, file_args, color=color)
+
+    def install_environment(
+            prefix: Prefix,
+            version: str,
+            additional_dependencies: Sequence[str],
+    ) -> None:
+        additional_dependencies = tuple(additional_dependencies)
+        directory = helpers.environment_dir(_dir, version)
+
+        env_dir = prefix.path(directory)
+        with clean_path_on_failure(env_dir):
+            if version != C.DEFAULT:
+                python = norm_version(version)
+            else:
+                python = os.path.realpath(sys.executable)
+            _make_venv(env_dir, python)
+            with in_env(prefix, version):
+                helpers.run_setup_cmd(
+                    prefix, ('pip', 'install', '.') + additional_dependencies,
+                )
+
+    return in_env, healthy, run_hook, install_environment
+
+
+def make_venv(envdir: str, python: str) -> None:
+    env = dict(os.environ, VIRTUALENV_NO_DOWNLOAD='1')
+    cmd = (sys.executable, '-mvirtualenv', envdir, '-p', python)
+    cmd_output_b(*cmd, env=env, cwd='/')
+
+
+_interface = py_interface(ENVIRONMENT_DIR, make_venv)
+in_env, healthy, run_hook, install_environment = _interface