/usr/lib/python3/dist-packages/_pytest/monkeypatch.py is in python3-pytest 2.6.3-2.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 | """ monkeypatching and mocking functionality. """
import os, sys
from py.builtin import _basestring
def pytest_funcarg__monkeypatch(request):
"""The returned ``monkeypatch`` funcarg provides these
helper methods to modify objects, dictionaries or os.environ::
monkeypatch.setattr(obj, name, value, raising=True)
monkeypatch.delattr(obj, name, raising=True)
monkeypatch.setitem(mapping, name, value)
monkeypatch.delitem(obj, name, raising=True)
monkeypatch.setenv(name, value, prepend=False)
monkeypatch.delenv(name, value, raising=True)
monkeypatch.syspath_prepend(path)
monkeypatch.chdir(path)
All modifications will be undone after the requesting
test function has finished. The ``raising``
parameter determines if a KeyError or AttributeError
will be raised if the set/deletion operation has no target.
"""
mpatch = monkeypatch()
request.addfinalizer(mpatch.undo)
return mpatch
def derive_importpath(import_path):
import pytest
if not isinstance(import_path, _basestring) or "." not in import_path:
raise TypeError("must be absolute import path string, not %r" %
(import_path,))
rest = []
target = import_path
while target:
try:
obj = __import__(target, None, None, "__doc__")
except ImportError:
if "." not in target:
__tracebackhide__ = True
pytest.fail("could not import any sub part: %s" %
import_path)
target, name = target.rsplit(".", 1)
rest.append(name)
else:
assert rest
try:
while len(rest) > 1:
attr = rest.pop()
obj = getattr(obj, attr)
attr = rest[0]
getattr(obj, attr)
except AttributeError:
__tracebackhide__ = True
pytest.fail("object %r has no attribute %r" % (obj, attr))
return attr, obj
class Notset:
def __repr__(self):
return "<notset>"
notset = Notset()
class monkeypatch:
""" object keeping a record of setattr/item/env/syspath changes. """
def __init__(self):
self._setattr = []
self._setitem = []
self._cwd = None
def setattr(self, target, name, value=notset, raising=True):
""" set attribute value on target, memorizing the old value.
By default raise AttributeError if the attribute did not exist.
For convenience you can specify a string as ``target`` which
will be interpreted as a dotted import path, with the last part
being the attribute name. Example:
``monkeypatch.setattr("os.getcwd", lambda x: "/")``
would set the ``getcwd`` function of the ``os`` module.
The ``raising`` value determines if the setattr should fail
if the attribute is not already present (defaults to True
which means it will raise).
"""
__tracebackhide__ = True
import inspect
if value is notset:
if not isinstance(target, _basestring):
raise TypeError("use setattr(target, name, value) or "
"setattr(target, value) with target being a dotted "
"import string")
value = name
name, target = derive_importpath(target)
oldval = getattr(target, name, notset)
if raising and oldval is notset:
raise AttributeError("%r has no attribute %r" %(target, name))
# avoid class descriptors like staticmethod/classmethod
if inspect.isclass(target):
oldval = target.__dict__.get(name, notset)
self._setattr.insert(0, (target, name, oldval))
setattr(target, name, value)
def delattr(self, target, name=notset, raising=True):
""" delete attribute ``name`` from ``target``, by default raise
AttributeError it the attribute did not previously exist.
If no ``name`` is specified and ``target`` is a string
it will be interpreted as a dotted import path with the
last part being the attribute name.
If raising is set to false, the attribute is allowed to not
pre-exist.
"""
__tracebackhide__ = True
if name is notset:
if not isinstance(target, _basestring):
raise TypeError("use delattr(target, name) or "
"delattr(target) with target being a dotted "
"import string")
name, target = derive_importpath(target)
if not hasattr(target, name):
if raising:
raise AttributeError(name)
else:
self._setattr.insert(0, (target, name,
getattr(target, name, notset)))
delattr(target, name)
def setitem(self, dic, name, value):
""" set dictionary entry ``name`` to value. """
self._setitem.insert(0, (dic, name, dic.get(name, notset)))
dic[name] = value
def delitem(self, dic, name, raising=True):
""" delete ``name`` from dict, raise KeyError if it doesn't exist."""
if name not in dic:
if raising:
raise KeyError(name)
else:
self._setitem.insert(0, (dic, name, dic.get(name, notset)))
del dic[name]
def setenv(self, name, value, prepend=None):
""" set environment variable ``name`` to ``value``. if ``prepend``
is a character, read the current environment variable value
and prepend the ``value`` adjoined with the ``prepend`` character."""
value = str(value)
if prepend and name in os.environ:
value = value + prepend + os.environ[name]
self.setitem(os.environ, name, value)
def delenv(self, name, raising=True):
""" delete ``name`` from environment, raise KeyError it not exists."""
self.delitem(os.environ, name, raising=raising)
def syspath_prepend(self, path):
""" prepend ``path`` to ``sys.path`` list of import locations. """
if not hasattr(self, '_savesyspath'):
self._savesyspath = sys.path[:]
sys.path.insert(0, str(path))
def chdir(self, path):
""" change the current working directory to the specified path
path can be a string or a py.path.local object
"""
if self._cwd is None:
self._cwd = os.getcwd()
if hasattr(path, "chdir"):
path.chdir()
else:
os.chdir(path)
def undo(self):
""" undo previous changes. This call consumes the
undo stack. Calling it a second time has no effect unless
you do more monkeypatching after the undo call."""
for obj, name, value in self._setattr:
if value is not notset:
setattr(obj, name, value)
else:
delattr(obj, name)
self._setattr[:] = []
for dictionary, name, value in self._setitem:
if value is notset:
try:
del dictionary[name]
except KeyError:
pass # was already deleted, so we have the desired state
else:
dictionary[name] = value
self._setitem[:] = []
if hasattr(self, '_savesyspath'):
sys.path[:] = self._savesyspath
del self._savesyspath
if self._cwd is not None:
os.chdir(self._cwd)
self._cwd = None
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