path: root/contrib/python/pytest/py2/_pytest/compat.py

# -*- coding: utf-8 -*-
""" 
python version compatibility code 
""" 
from __future__ import absolute_import 
from __future__ import division 
from __future__ import print_function 
 
import codecs 
import functools 
import inspect 
import re 
import sys 
from contextlib import contextmanager 
 
import attr
import py 
import six 
from six import text_type 
 
import _pytest 
from _pytest._io.saferepr import saferepr
from _pytest.outcomes import fail 
from _pytest.outcomes import TEST_OUTCOME 
 
try: 
    import enum 
except ImportError:  # pragma: no cover 
    # Only available in Python 3.4+ or as a backport 
    enum = None 
 
_PY3 = sys.version_info > (3, 0) 
_PY2 = not _PY3 
 
 
if _PY3: 
    from inspect import signature, Parameter as Parameter 
else: 
    from funcsigs import signature, Parameter as Parameter 
 
NOTSET = object() 
 
PY35 = sys.version_info[:2] >= (3, 5) 
PY36 = sys.version_info[:2] >= (3, 6) 
MODULE_NOT_FOUND_ERROR = "ModuleNotFoundError" if PY36 else "ImportError" 
 
 
if _PY3: 
    from collections.abc import MutableMapping as MappingMixin 
    from collections.abc import Iterable, Mapping, Sequence, Sized
else: 
    # those raise DeprecationWarnings in Python >=3.7 
    from collections import MutableMapping as MappingMixin  # noqa 
    from collections import Iterable, Mapping, Sequence, Sized  # noqa
 
 
if sys.version_info >= (3, 4): 
    from importlib.util import spec_from_file_location 
else: 
 
    def spec_from_file_location(*_, **__): 
        return None 
 
 
if sys.version_info >= (3, 8):
    from importlib import metadata as importlib_metadata  # noqa
else:
    import importlib_metadata  # noqa


def _format_args(func): 
    return str(signature(func)) 
 
 
isfunction = inspect.isfunction 
isclass = inspect.isclass 
# used to work around a python2 exception info leak 
exc_clear = getattr(sys, "exc_clear", lambda: None) 
# The type of re.compile objects is not exposed in Python. 
REGEX_TYPE = type(re.compile("")) 
 
 
def is_generator(func): 
    genfunc = inspect.isgeneratorfunction(func) 
    return genfunc and not iscoroutinefunction(func) 
 
 
def iscoroutinefunction(func): 
    """Return True if func is a decorated coroutine function. 
 
    Note: copied and modified from Python 3.5's builtin couroutines.py to avoid import asyncio directly, 
    which in turns also initializes the "logging" module as side-effect (see issue #8). 
    """ 
    return getattr(func, "_is_coroutine", False) or ( 
        hasattr(inspect, "iscoroutinefunction") and inspect.iscoroutinefunction(func) 
    ) 
 
 
def getlocation(function, curdir): 
    function = get_real_func(function) 
    fn = py.path.local(inspect.getfile(function)) 
    lineno = function.__code__.co_firstlineno 
    if fn.relto(curdir): 
        fn = fn.relto(curdir) 
    return "%s:%d" % (fn, lineno + 1) 
 
 
def num_mock_patch_args(function): 
    """ return number of arguments used up by mock arguments (if any) """ 
    patchings = getattr(function, "patchings", None) 
    if not patchings: 
        return 0 
    mock_modules = [sys.modules.get("mock"), sys.modules.get("unittest.mock")] 
    if any(mock_modules): 
        sentinels = [m.DEFAULT for m in mock_modules if m is not None] 
        return len( 
            [p for p in patchings if not p.attribute_name and p.new in sentinels] 
        ) 
    return len(patchings) 
 
 
def getfuncargnames(function, is_method=False, cls=None): 
    """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. 
 
    @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 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(function.__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 
 
 
@contextmanager 
def dummy_context_manager(): 
    """Context manager that does nothing, useful in situations where you might need an actual context manager or not 
    depending on some condition. Using this allow to keep the same code""" 
    yield 
 
 
def get_default_arg_names(function): 
    # 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: u"\\x{:02x}".format(i) for i in range(128) if i not in range(32, 127)
}
_non_printable_ascii_translate_table.update(
    {ord("\t"): u"\\t", ord("\r"): u"\\r", ord("\n"): u"\\n"}
)


def _translate_non_printable(s):
    return s.translate(_non_printable_ascii_translate_table)


if _PY3: 
    STRING_TYPES = bytes, str 
    UNICODE_TYPES = six.text_type 
 
    if PY35: 
 
        def _bytes_to_ascii(val): 
            return val.decode("ascii", "backslashreplace") 
 
    else: 
 
        def _bytes_to_ascii(val): 
            if val: 
                # source: http://goo.gl/bGsnwC 
                encoded_bytes, _ = codecs.escape_encode(val) 
                return encoded_bytes.decode("ascii") 
            else: 
                # empty bytes crashes codecs.escape_encode (#1087) 
                return "" 
 
    def ascii_escaped(val): 
        """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' -> u'\\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
        return ret
 
 
else: 
    STRING_TYPES = six.string_types 
    UNICODE_TYPES = six.text_type 
 
    def ascii_escaped(val): 
        """In py2 bytes and str are the same type, so return if it's a bytes 
        object, return it unchanged if it is a full ascii string, 
        otherwise escape it into its binary form. 
 
        If it's a unicode string, change the unicode characters into 
        unicode escapes. 
 
        """ 
        if isinstance(val, bytes): 
            try: 
                ret = val.decode("utf-8")
            except UnicodeDecodeError: 
                ret = val.decode("utf-8", "ignore")
        else: 
            ret = val.encode("utf-8", "replace").decode("utf-8")
        return ret
 
 
class _PytestWrapper(object): 
    """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. 
    """ 
 
    def __init__(self, obj): 
        self.obj = obj 
 
 
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 
 
 
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: 
        return obj 
    if is_method and hasattr(obj, "__get__") and callable(obj.__get__): 
        obj = obj.__get__(holder) 
    return obj 
 
 
def getfslineno(obj): 
    # xxx let decorators etc specify a sane ordering 
    obj = get_real_func(obj) 
    if hasattr(obj, "place_as"): 
        obj = obj.place_as 
    fslineno = _pytest._code.getfslineno(obj) 
    assert isinstance(fslineno[1], int), obj 
    return fslineno 
 
 
def getimfunc(func): 
    try: 
        return func.__func__ 
    except AttributeError: 
        return func 
 
 
def safe_getattr(object, name, default): 
    """ 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 
 
 
def safe_isclass(obj): 
    """Ignore any exception via isinstance on Python 3.""" 
    try: 
        return isclass(obj) 
    except Exception: 
        return False 
 
 
def _is_unittest_unexpected_success_a_failure(): 
    """Return if the test suite should fail if an @expectedFailure unittest test PASSES. 
 
    From https://docs.python.org/3/library/unittest.html?highlight=unittest#unittest.TestResult.wasSuccessful:
        Changed in version 3.4: Returns False if there were any 
        unexpectedSuccesses from tests marked with the expectedFailure() decorator. 
    """ 
    return sys.version_info >= (3, 4) 
 
 
if _PY3: 
 
    def safe_str(v): 
        """returns v as string""" 
        try:
            return str(v)
        except UnicodeEncodeError:
            return str(v, encoding="utf-8")
 
 
else: 
 
    def safe_str(v): 
        """returns v as string, converting to utf-8 if necessary"""
        try: 
            return str(v) 
        except UnicodeError: 
            if not isinstance(v, text_type): 
                v = text_type(v) 
            errors = "replace" 
            return v.encode("utf-8", errors) 
 
 
COLLECT_FAKEMODULE_ATTRIBUTES = ( 
    "Collector", 
    "Module", 
    "Function", 
    "Instance", 
    "Session", 
    "Item", 
    "Class", 
    "File", 
    "_fillfuncargs", 
) 
 
 
def _setup_collect_fakemodule(): 
    from types import ModuleType 
    import pytest 
 
    pytest.collect = ModuleType("pytest.collect") 
    pytest.collect.__all__ = []  # used for setns 
    for attribute in COLLECT_FAKEMODULE_ATTRIBUTES:
        setattr(pytest.collect, attribute, getattr(pytest, attribute))
 
 
if _PY2: 
    # Without this the test_dupfile_on_textio will fail, otherwise CaptureIO could directly inherit from StringIO. 
    from py.io import TextIO 
 
    class CaptureIO(TextIO): 
        @property 
        def encoding(self): 
            return getattr(self, "_encoding", "UTF-8") 
 
 
else: 
    import io 
 
    class CaptureIO(io.TextIOWrapper): 
        def __init__(self): 
            super(CaptureIO, self).__init__( 
                io.BytesIO(), encoding="UTF-8", newline="", write_through=True 
            ) 
 
        def getvalue(self): 
            return self.buffer.getvalue().decode("UTF-8") 
 
 
class FuncargnamesCompatAttr(object): 
    """ helper class so that Metafunc, Function and FixtureRequest 
    don't need to each define the "funcargnames" compatibility attribute. 
    """ 
 
    @property 
    def funcargnames(self): 
        """ alias attribute for ``fixturenames`` for pre-2.3 compatibility""" 
        return self.fixturenames 
 
 
if six.PY2: 
 
    def lru_cache(*_, **__): 
        def dec(fn): 
            return fn 
 
        return dec 
 
 
else: 
    from functools import lru_cache  # noqa: F401 


if getattr(attr, "__version_info__", ()) >= (19, 2):
    ATTRS_EQ_FIELD = "eq"
else:
    ATTRS_EQ_FIELD = "cmp"