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- """Python version compatibility code."""
- import enum
- import functools
- import inspect
- import os
- import sys
- from contextlib import contextmanager
- from inspect import Parameter
- from inspect import signature
- from pathlib import Path
- from typing import Any
- from typing import Callable
- from typing import Generic
- from typing import Optional
- from typing import Tuple
- from typing import TYPE_CHECKING
- from typing import TypeVar
- from typing import Union
- import attr
- import py
- if TYPE_CHECKING:
- from typing import NoReturn
- from typing_extensions import Final
- _T = TypeVar("_T")
- _S = TypeVar("_S")
- #: constant to prepare valuing pylib path replacements/lazy proxies later on
- # intended for removal in pytest 8.0 or 9.0
- # fmt: off
- # intentional space to create a fake difference for the verification
- LEGACY_PATH = py.path. local
- # fmt: on
- def legacy_path(path: Union[str, "os.PathLike[str]"]) -> LEGACY_PATH:
- """Internal wrapper to prepare lazy proxies for legacy_path instances"""
- return LEGACY_PATH(path)
- # fmt: off
- # Singleton type for NOTSET, as described in:
- # https://www.python.org/dev/peps/pep-0484/#support-for-singleton-types-in-unions
- class NotSetType(enum.Enum):
- token = 0
- NOTSET: "Final" = NotSetType.token # noqa: E305
- # fmt: on
- if sys.version_info >= (3, 8):
- from importlib import metadata as importlib_metadata
- else:
- import importlib_metadata # noqa: F401
- def _format_args(func: Callable[..., Any]) -> str:
- return str(signature(func))
- def is_generator(func: object) -> bool:
- genfunc = inspect.isgeneratorfunction(func)
- return genfunc and not iscoroutinefunction(func)
- def iscoroutinefunction(func: object) -> bool:
- """Return True if func is a coroutine function (a function defined with async
- def syntax, and doesn't contain yield), or a function decorated with
- @asyncio.coroutine.
- Note: copied and modified from Python 3.5's builtin couroutines.py to avoid
- importing asyncio directly, which in turns also initializes the "logging"
- module as a side-effect (see issue #8).
- """
- return inspect.iscoroutinefunction(func) or getattr(func, "_is_coroutine", False)
- def is_async_function(func: object) -> bool:
- """Return True if the given function seems to be an async function or
- an async generator."""
- return iscoroutinefunction(func) or inspect.isasyncgenfunction(func)
- def getlocation(function, curdir: Optional[str] = None) -> str:
- function = get_real_func(function)
- fn = Path(inspect.getfile(function))
- lineno = function.__code__.co_firstlineno
- if curdir is not None:
- try:
- relfn = fn.relative_to(curdir)
- except ValueError:
- pass
- else:
- return "%s:%d" % (relfn, lineno + 1)
- return "%s:%d" % (fn, lineno + 1)
- def num_mock_patch_args(function) -> int:
- """Return number of arguments used up by mock arguments (if any)."""
- patchings = getattr(function, "patchings", None)
- if not patchings:
- return 0
- mock_sentinel = getattr(sys.modules.get("mock"), "DEFAULT", object())
- ut_mock_sentinel = getattr(sys.modules.get("unittest.mock"), "DEFAULT", object())
- return len(
- [
- p
- for p in patchings
- if not p.attribute_name
- and (p.new is mock_sentinel or p.new is ut_mock_sentinel)
- ]
- )
- def getfuncargnames(
- function: Callable[..., Any],
- *,
- name: str = "",
- is_method: bool = False,
- cls: Optional[type] = None,
- ) -> Tuple[str, ...]:
- """Return the names of a function's mandatory arguments.
- Should return the names of all function arguments that:
- * Aren't bound to an instance or type as in instance or class methods.
- * Don't have default values.
- * Aren't bound with functools.partial.
- * Aren't replaced with mocks.
- The is_method and cls arguments indicate that the function should
- be treated as a bound method even though it's not unless, only in
- the case of cls, the function is a static method.
- The name parameter should be the original name in which the function was collected.
- """
- # TODO(RonnyPfannschmidt): This function should be refactored when we
- # revisit fixtures. The fixture mechanism should ask the node for
- # the fixture names, and not try to obtain directly from the
- # function object well after collection has occurred.
- # The parameters attribute of a Signature object contains an
- # ordered mapping of parameter names to Parameter instances. This
- # creates a tuple of the names of the parameters that don't have
- # defaults.
- try:
- parameters = signature(function).parameters
- except (ValueError, TypeError) as e:
- from _pytest.outcomes import fail
- fail(
- f"Could not determine arguments of {function!r}: {e}",
- pytrace=False,
- )
- arg_names = tuple(
- p.name
- for p in parameters.values()
- if (
- p.kind is Parameter.POSITIONAL_OR_KEYWORD
- or p.kind is Parameter.KEYWORD_ONLY
- )
- and p.default is Parameter.empty
- )
- if not name:
- name = function.__name__
- # If this function should be treated as a bound method even though
- # it's passed as an unbound method or function, remove the first
- # parameter name.
- if is_method or (
- # Not using `getattr` because we don't want to resolve the staticmethod.
- # Not using `cls.__dict__` because we want to check the entire MRO.
- cls
- and not isinstance(
- inspect.getattr_static(cls, name, default=None), staticmethod
- )
- ):
- arg_names = arg_names[1:]
- # Remove any names that will be replaced with mocks.
- if hasattr(function, "__wrapped__"):
- arg_names = arg_names[num_mock_patch_args(function) :]
- return arg_names
- if sys.version_info < (3, 7):
- @contextmanager
- def nullcontext():
- yield
- else:
- from contextlib import nullcontext as nullcontext # noqa: F401
- def get_default_arg_names(function: Callable[..., Any]) -> Tuple[str, ...]:
- # Note: this code intentionally mirrors the code at the beginning of
- # getfuncargnames, to get the arguments which were excluded from its result
- # because they had default values.
- return tuple(
- p.name
- for p in signature(function).parameters.values()
- if p.kind in (Parameter.POSITIONAL_OR_KEYWORD, Parameter.KEYWORD_ONLY)
- and p.default is not Parameter.empty
- )
- _non_printable_ascii_translate_table = {
- i: f"\\x{i:02x}" for i in range(128) if i not in range(32, 127)
- }
- _non_printable_ascii_translate_table.update(
- {ord("\t"): "\\t", ord("\r"): "\\r", ord("\n"): "\\n"}
- )
- def _translate_non_printable(s: str) -> str:
- return s.translate(_non_printable_ascii_translate_table)
- STRING_TYPES = bytes, str
- def _bytes_to_ascii(val: bytes) -> str:
- return val.decode("ascii", "backslashreplace")
- def ascii_escaped(val: Union[bytes, str]) -> str:
- r"""If val is pure ASCII, return it as an str, otherwise, escape
- bytes objects into a sequence of escaped bytes:
- b'\xc3\xb4\xc5\xd6' -> r'\xc3\xb4\xc5\xd6'
- and escapes unicode objects into a sequence of escaped unicode
- ids, e.g.:
- r'4\nV\U00043efa\x0eMXWB\x1e\u3028\u15fd\xcd\U0007d944'
- Note:
- The obvious "v.decode('unicode-escape')" will return
- valid UTF-8 unicode if it finds them in bytes, but we
- want to return escaped bytes for any byte, even if they match
- a UTF-8 string.
- """
- if isinstance(val, bytes):
- ret = _bytes_to_ascii(val)
- else:
- ret = val.encode("unicode_escape").decode("ascii")
- return _translate_non_printable(ret)
- @attr.s
- class _PytestWrapper:
- """Dummy wrapper around a function object for internal use only.
- Used to correctly unwrap the underlying function object when we are
- creating fixtures, because we wrap the function object ourselves with a
- decorator to issue warnings when the fixture function is called directly.
- """
- obj = attr.ib()
- def get_real_func(obj):
- """Get the real function object of the (possibly) wrapped object by
- functools.wraps or functools.partial."""
- start_obj = obj
- for i in range(100):
- # __pytest_wrapped__ is set by @pytest.fixture when wrapping the fixture function
- # to trigger a warning if it gets called directly instead of by pytest: we don't
- # want to unwrap further than this otherwise we lose useful wrappings like @mock.patch (#3774)
- new_obj = getattr(obj, "__pytest_wrapped__", None)
- if isinstance(new_obj, _PytestWrapper):
- obj = new_obj.obj
- break
- new_obj = getattr(obj, "__wrapped__", None)
- if new_obj is None:
- break
- obj = new_obj
- else:
- from _pytest._io.saferepr import saferepr
- raise ValueError(
- ("could not find real function of {start}\nstopped at {current}").format(
- start=saferepr(start_obj), current=saferepr(obj)
- )
- )
- if isinstance(obj, functools.partial):
- obj = obj.func
- return obj
- def get_real_method(obj, holder):
- """Attempt to obtain the real function object that might be wrapping
- ``obj``, while at the same time returning a bound method to ``holder`` if
- the original object was a bound method."""
- try:
- is_method = hasattr(obj, "__func__")
- obj = get_real_func(obj)
- except Exception: # pragma: no cover
- return obj
- if is_method and hasattr(obj, "__get__") and callable(obj.__get__):
- obj = obj.__get__(holder)
- return obj
- def getimfunc(func):
- try:
- return func.__func__
- except AttributeError:
- return func
- def safe_getattr(object: Any, name: str, default: Any) -> Any:
- """Like getattr but return default upon any Exception or any OutcomeException.
- Attribute access can potentially fail for 'evil' Python objects.
- See issue #214.
- It catches OutcomeException because of #2490 (issue #580), new outcomes
- are derived from BaseException instead of Exception (for more details
- check #2707).
- """
- from _pytest.outcomes import TEST_OUTCOME
- try:
- return getattr(object, name, default)
- except TEST_OUTCOME:
- return default
- def safe_isclass(obj: object) -> bool:
- """Ignore any exception via isinstance on Python 3."""
- try:
- return inspect.isclass(obj)
- except Exception:
- return False
- if TYPE_CHECKING:
- if sys.version_info >= (3, 8):
- from typing import final as final
- else:
- from typing_extensions import final as final
- elif sys.version_info >= (3, 8):
- from typing import final as final
- else:
- def final(f):
- return f
- if sys.version_info >= (3, 8):
- from functools import cached_property as cached_property
- else:
- from typing import overload
- from typing import Type
- class cached_property(Generic[_S, _T]):
- __slots__ = ("func", "__doc__")
- def __init__(self, func: Callable[[_S], _T]) -> None:
- self.func = func
- self.__doc__ = func.__doc__
- @overload
- def __get__(
- self, instance: None, owner: Optional[Type[_S]] = ...
- ) -> "cached_property[_S, _T]":
- ...
- @overload
- def __get__(self, instance: _S, owner: Optional[Type[_S]] = ...) -> _T:
- ...
- def __get__(self, instance, owner=None):
- if instance is None:
- return self
- value = instance.__dict__[self.func.__name__] = self.func(instance)
- return value
- # Perform exhaustiveness checking.
- #
- # Consider this example:
- #
- # MyUnion = Union[int, str]
- #
- # def handle(x: MyUnion) -> int {
- # if isinstance(x, int):
- # return 1
- # elif isinstance(x, str):
- # return 2
- # else:
- # raise Exception('unreachable')
- #
- # Now suppose we add a new variant:
- #
- # MyUnion = Union[int, str, bytes]
- #
- # After doing this, we must remember ourselves to go and update the handle
- # function to handle the new variant.
- #
- # With `assert_never` we can do better:
- #
- # // raise Exception('unreachable')
- # return assert_never(x)
- #
- # Now, if we forget to handle the new variant, the type-checker will emit a
- # compile-time error, instead of the runtime error we would have gotten
- # previously.
- #
- # This also work for Enums (if you use `is` to compare) and Literals.
- def assert_never(value: "NoReturn") -> "NoReturn":
- assert False, f"Unhandled value: {value} ({type(value).__name__})"
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