Source code for _pytest.compat

"""
python version compatibility code
"""
import functools
import inspect
import io
import os
import re
import sys
from contextlib import contextmanager
from inspect import Parameter
from inspect import signature
from typing import Any
from typing import Callable
from typing import Generic
from typing import IO
from typing import Optional
from typing import overload
from typing import Tuple
from typing import TypeVar
from typing import Union

import attr
import py

from _pytest._io.saferepr import saferepr
from _pytest.outcomes import fail
from _pytest.outcomes import TEST_OUTCOME

if sys.version_info < (3, 5, 2):
    TYPE_CHECKING = False  # type: bool
else:
    from typing import TYPE_CHECKING


if TYPE_CHECKING:
    from types import ModuleType  # noqa: F401 (used in type string)
    from typing import Type  # noqa: F401 (used in type string)


_T = TypeVar("_T")
_S = TypeVar("_S")


NOTSET = object()

MODULE_NOT_FOUND_ERROR = (
    "ModuleNotFoundError" if sys.version_info[:2] >= (3, 6) else "ImportError"
)


if sys.version_info >= (3, 8):
    from importlib import metadata as importlib_metadata
else:
    import importlib_metadata  # noqa: F401


[docs]def _format_args(func: Callable[..., Any]) -> str: return str(signature(func))
# The type of re.compile objects is not exposed in Python. REGEX_TYPE = type(re.compile("")) if sys.version_info < (3, 6): def fspath(p): """os.fspath replacement, useful to point out when we should replace it by the real function once we drop py35. """ return str(p) else: fspath = os.fspath
[docs]def is_generator(func: object) -> bool: genfunc = inspect.isgeneratorfunction(func) return genfunc and not iscoroutinefunction(func)
[docs]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)
[docs]def getlocation(function, curdir=None) -> str: function = get_real_func(function) fn = py.path.local(inspect.getfile(function)) lineno = function.__code__.co_firstlineno if curdir is not None: relfn = fn.relto(curdir) if relfn: return "%s:%d" % (relfn, lineno + 1) return "%s:%d" % (fn, lineno + 1)
[docs]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) ] )
[docs]def getfuncargnames( function: Callable[..., Any], *, name: str = "", is_method: bool = False, cls: Optional[type] = None ) -> Tuple[str, ...]: """Returns the names of a function's mandatory arguments. This 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: fail( "Could not determine arguments of {!r}: {}".format(function, 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 ( cls and not isinstance(cls.__dict__.get(name, 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 # noqa
[docs]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: "\\x{:02x}".format(i) 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"} )
[docs]def _translate_non_printable(s: str) -> str: return s.translate(_non_printable_ascii_translate_table)
STRING_TYPES = bytes, str
[docs]def _bytes_to_ascii(val: bytes) -> str: return val.decode("ascii", "backslashreplace")
[docs]def ascii_escaped(val: Union[bytes, str]) -> str: """If val is pure ascii, returns it as a str(). Otherwise, escapes bytes objects into a sequence of escaped bytes: b'\xc3\xb4\xc5\xd6' -> '\\xc3\\xb4\\xc5\\xd6' and escapes unicode objects into a sequence of escaped unicode ids, e.g.: '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)
[docs]@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()
[docs]def get_real_func(obj): """ gets 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: 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
[docs]def get_real_method(obj, holder): """ Attempts 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
[docs]def getimfunc(func): try: return func.__func__ except AttributeError: return func
[docs]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) """ try: return getattr(object, name, default) except TEST_OUTCOME: return default
[docs]def safe_isclass(obj: object) -> bool: """Ignore any exception via isinstance on Python 3.""" try: return inspect.isclass(obj) except Exception: return False
[docs]def _setup_collect_fakemodule() -> "ModuleType": """Setup pytest.collect fake module for backward compatibility.""" from types import ModuleType import _pytest.nodes collect_fakemodule_attributes = ( ("Collector", _pytest.nodes.Collector), ("Module", _pytest.python.Module), ("Function", _pytest.python.Function), ("Instance", _pytest.python.Instance), ("Session", _pytest.main.Session), ("Item", _pytest.nodes.Item), ("Class", _pytest.python.Class), ("File", _pytest.nodes.File), ("_fillfuncargs", _pytest.fixtures.fillfixtures), ) mod = ModuleType("pytest.collect") mod.__all__ = [] # type: ignore # used for setns (obsolete?) for attr_name, value in collect_fakemodule_attributes: setattr(mod, attr_name, value) return mod
[docs]class CaptureIO(io.TextIOWrapper): def __init__(self) -> None: super().__init__(io.BytesIO(), encoding="UTF-8", newline="", write_through=True)
[docs] def getvalue(self) -> str: assert isinstance(self.buffer, io.BytesIO) return self.buffer.getvalue().decode("UTF-8")
[docs]class CaptureAndPassthroughIO(CaptureIO): def __init__(self, other: IO) -> None: self._other = other super().__init__()
[docs] def write(self, s) -> int: super().write(s) return self._other.write(s)
if sys.version_info < (3, 5, 2): def overload(f): # noqa: F811 return f if getattr(attr, "__version_info__", ()) >= (19, 2): ATTRS_EQ_FIELD = "eq" else: ATTRS_EQ_FIELD = "cmp" if sys.version_info < (3,): from pipes import quote as shell_quote else: from shlex import quote as shell_quote # noqa: F401 if sys.version_info >= (3, 8): from functools import cached_property else: 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]": raise NotImplementedError() @overload # noqa: F811 def __get__( # noqa: F811 self, instance: _S, owner: Optional["Type[_S]"] = ... ) -> _T: raise NotImplementedError() def __get__(self, instance, owner=None): # noqa: F811 if instance is None: return self value = instance.__dict__[self.func.__name__] = self.func(instance) return value # Sometimes an algorithm needs a dict which yields items in the order in which # they were inserted when iterated. Since Python 3.7, `dict` preserves # insertion order. Since `dict` is faster and uses less memory than # `OrderedDict`, prefer to use it if possible. if sys.version_info >= (3, 7): order_preserving_dict = dict else: from collections import OrderedDict order_preserving_dict = OrderedDict