test_ok2/_pytest/fixtures.py

1135 lines
44 KiB
Python

import sys
from py._code.code import FormattedExcinfo
import py
import pytest
import warnings
import inspect
import _pytest
from _pytest._code.code import TerminalRepr
from _pytest.compat import (
NOTSET, exc_clear, _format_args,
getfslineno, get_real_func,
is_generator, isclass, getimfunc,
getlocation, getfuncargnames,
)
def pytest_sessionstart(session):
session._fixturemanager = FixtureManager(session)
scopename2class = {}
scope2props = dict(session=())
scope2props["module"] = ("fspath", "module")
scope2props["class"] = scope2props["module"] + ("cls",)
scope2props["instance"] = scope2props["class"] + ("instance", )
scope2props["function"] = scope2props["instance"] + ("function", "keywords")
def scopeproperty(name=None, doc=None):
def decoratescope(func):
scopename = name or func.__name__
def provide(self):
if func.__name__ in scope2props[self.scope]:
return func(self)
raise AttributeError("%s not available in %s-scoped context" % (
scopename, self.scope))
return property(provide, None, None, func.__doc__)
return decoratescope
def pytest_namespace():
scopename2class.update({
'class': pytest.Class,
'module': pytest.Module,
'function': pytest.Item,
})
return {
'fixture': fixture,
'yield_fixture': yield_fixture,
'collect': {'_fillfuncargs': fillfixtures}
}
def get_scope_node(node, scope):
cls = scopename2class.get(scope)
if cls is None:
if scope == "session":
return node.session
raise ValueError("unknown scope")
return node.getparent(cls)
def add_funcarg_pseudo_fixture_def(collector, metafunc, fixturemanager):
# this function will transform all collected calls to a functions
# if they use direct funcargs (i.e. direct parametrization)
# because we want later test execution to be able to rely on
# an existing FixtureDef structure for all arguments.
# XXX we can probably avoid this algorithm if we modify CallSpec2
# to directly care for creating the fixturedefs within its methods.
if not metafunc._calls[0].funcargs:
return # this function call does not have direct parametrization
# collect funcargs of all callspecs into a list of values
arg2params = {}
arg2scope = {}
for callspec in metafunc._calls:
for argname, argvalue in callspec.funcargs.items():
assert argname not in callspec.params
callspec.params[argname] = argvalue
arg2params_list = arg2params.setdefault(argname, [])
callspec.indices[argname] = len(arg2params_list)
arg2params_list.append(argvalue)
if argname not in arg2scope:
scopenum = callspec._arg2scopenum.get(argname,
scopenum_function)
arg2scope[argname] = scopes[scopenum]
callspec.funcargs.clear()
# register artificial FixtureDef's so that later at test execution
# time we can rely on a proper FixtureDef to exist for fixture setup.
arg2fixturedefs = metafunc._arg2fixturedefs
for argname, valuelist in arg2params.items():
# if we have a scope that is higher than function we need
# to make sure we only ever create an according fixturedef on
# a per-scope basis. We thus store and cache the fixturedef on the
# node related to the scope.
scope = arg2scope[argname]
node = None
if scope != "function":
node = get_scope_node(collector, scope)
if node is None:
assert scope == "class" and isinstance(collector, pytest.Module)
# use module-level collector for class-scope (for now)
node = collector
if node and argname in node._name2pseudofixturedef:
arg2fixturedefs[argname] = [node._name2pseudofixturedef[argname]]
else:
fixturedef = FixtureDef(fixturemanager, '', argname,
get_direct_param_fixture_func,
arg2scope[argname],
valuelist, False, False)
arg2fixturedefs[argname] = [fixturedef]
if node is not None:
node._name2pseudofixturedef[argname] = fixturedef
def getfixturemarker(obj):
""" return fixturemarker or None if it doesn't exist or raised
exceptions."""
try:
return getattr(obj, "_pytestfixturefunction", None)
except KeyboardInterrupt:
raise
except Exception:
# some objects raise errors like request (from flask import request)
# we don't expect them to be fixture functions
return None
def get_parametrized_fixture_keys(item, scopenum):
""" return list of keys for all parametrized arguments which match
the specified scope. """
assert scopenum < scopenum_function # function
try:
cs = item.callspec
except AttributeError:
pass
else:
# cs.indictes.items() is random order of argnames but
# then again different functions (items) can change order of
# arguments so it doesn't matter much probably
for argname, param_index in cs.indices.items():
if cs._arg2scopenum[argname] != scopenum:
continue
if scopenum == 0: # session
key = (argname, param_index)
elif scopenum == 1: # module
key = (argname, param_index, item.fspath)
elif scopenum == 2: # class
key = (argname, param_index, item.fspath, item.cls)
yield key
# algorithm for sorting on a per-parametrized resource setup basis
# it is called for scopenum==0 (session) first and performs sorting
# down to the lower scopes such as to minimize number of "high scope"
# setups and teardowns
def reorder_items(items):
argkeys_cache = {}
for scopenum in range(0, scopenum_function):
argkeys_cache[scopenum] = d = {}
for item in items:
keys = set(get_parametrized_fixture_keys(item, scopenum))
if keys:
d[item] = keys
return reorder_items_atscope(items, set(), argkeys_cache, 0)
def reorder_items_atscope(items, ignore, argkeys_cache, scopenum):
if scopenum >= scopenum_function or len(items) < 3:
return items
items_done = []
while 1:
items_before, items_same, items_other, newignore = \
slice_items(items, ignore, argkeys_cache[scopenum])
items_before = reorder_items_atscope(
items_before, ignore, argkeys_cache,scopenum+1)
if items_same is None:
# nothing to reorder in this scope
assert items_other is None
return items_done + items_before
items_done.extend(items_before)
items = items_same + items_other
ignore = newignore
def slice_items(items, ignore, scoped_argkeys_cache):
# we pick the first item which uses a fixture instance in the
# requested scope and which we haven't seen yet. We slice the input
# items list into a list of items_nomatch, items_same and
# items_other
if scoped_argkeys_cache: # do we need to do work at all?
it = iter(items)
# first find a slicing key
for i, item in enumerate(it):
argkeys = scoped_argkeys_cache.get(item)
if argkeys is not None:
argkeys = argkeys.difference(ignore)
if argkeys: # found a slicing key
slicing_argkey = argkeys.pop()
items_before = items[:i]
items_same = [item]
items_other = []
# now slice the remainder of the list
for item in it:
argkeys = scoped_argkeys_cache.get(item)
if argkeys and slicing_argkey in argkeys and \
slicing_argkey not in ignore:
items_same.append(item)
else:
items_other.append(item)
newignore = ignore.copy()
newignore.add(slicing_argkey)
return (items_before, items_same, items_other, newignore)
return items, None, None, None
class FuncargnamesCompatAttr:
""" 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
def fillfixtures(function):
""" fill missing funcargs for a test function. """
try:
request = function._request
except AttributeError:
# XXX this special code path is only expected to execute
# with the oejskit plugin. It uses classes with funcargs
# and we thus have to work a bit to allow this.
fm = function.session._fixturemanager
fi = fm.getfixtureinfo(function.parent, function.obj, None)
function._fixtureinfo = fi
request = function._request = FixtureRequest(function)
request._fillfixtures()
# prune out funcargs for jstests
newfuncargs = {}
for name in fi.argnames:
newfuncargs[name] = function.funcargs[name]
function.funcargs = newfuncargs
else:
request._fillfixtures()
def get_direct_param_fixture_func(request):
return request.param
class FuncFixtureInfo:
def __init__(self, argnames, names_closure, name2fixturedefs):
self.argnames = argnames
self.names_closure = names_closure
self.name2fixturedefs = name2fixturedefs
class FixtureRequest(FuncargnamesCompatAttr):
""" A request for a fixture from a test or fixture function.
A request object gives access to the requesting test context
and has an optional ``param`` attribute in case
the fixture is parametrized indirectly.
"""
def __init__(self, pyfuncitem):
self._pyfuncitem = pyfuncitem
#: fixture for which this request is being performed
self.fixturename = None
#: Scope string, one of "function", "class", "module", "session"
self.scope = "function"
self._fixture_values = {} # argname -> fixture value
self._fixture_defs = {} # argname -> FixtureDef
fixtureinfo = pyfuncitem._fixtureinfo
self._arg2fixturedefs = fixtureinfo.name2fixturedefs.copy()
self._arg2index = {}
self._fixturemanager = pyfuncitem.session._fixturemanager
@property
def fixturenames(self):
# backward incompatible note: now a readonly property
return list(self._pyfuncitem._fixtureinfo.names_closure)
@property
def node(self):
""" underlying collection node (depends on current request scope)"""
return self._getscopeitem(self.scope)
def _getnextfixturedef(self, argname):
fixturedefs = self._arg2fixturedefs.get(argname, None)
if fixturedefs is None:
# we arrive here because of a a dynamic call to
# getfixturevalue(argname) usage which was naturally
# not known at parsing/collection time
parentid = self._pyfuncitem.parent.nodeid
fixturedefs = self._fixturemanager.getfixturedefs(argname, parentid)
self._arg2fixturedefs[argname] = fixturedefs
# fixturedefs list is immutable so we maintain a decreasing index
index = self._arg2index.get(argname, 0) - 1
if fixturedefs is None or (-index > len(fixturedefs)):
raise FixtureLookupError(argname, self)
self._arg2index[argname] = index
return fixturedefs[index]
@property
def config(self):
""" the pytest config object associated with this request. """
return self._pyfuncitem.config
@scopeproperty()
def function(self):
""" test function object if the request has a per-function scope. """
return self._pyfuncitem.obj
@scopeproperty("class")
def cls(self):
""" class (can be None) where the test function was collected. """
clscol = self._pyfuncitem.getparent(pytest.Class)
if clscol:
return clscol.obj
@property
def instance(self):
""" instance (can be None) on which test function was collected. """
# unittest support hack, see _pytest.unittest.TestCaseFunction
try:
return self._pyfuncitem._testcase
except AttributeError:
function = getattr(self, "function", None)
if function is not None:
return py.builtin._getimself(function)
@scopeproperty()
def module(self):
""" python module object where the test function was collected. """
return self._pyfuncitem.getparent(pytest.Module).obj
@scopeproperty()
def fspath(self):
""" the file system path of the test module which collected this test. """
return self._pyfuncitem.fspath
@property
def keywords(self):
""" keywords/markers dictionary for the underlying node. """
return self.node.keywords
@property
def session(self):
""" pytest session object. """
return self._pyfuncitem.session
def addfinalizer(self, finalizer):
""" add finalizer/teardown function to be called after the
last test within the requesting test context finished
execution. """
# XXX usually this method is shadowed by fixturedef specific ones
self._addfinalizer(finalizer, scope=self.scope)
def _addfinalizer(self, finalizer, scope):
colitem = self._getscopeitem(scope)
self._pyfuncitem.session._setupstate.addfinalizer(
finalizer=finalizer, colitem=colitem)
def applymarker(self, marker):
""" Apply a marker to a single test function invocation.
This method is useful if you don't want to have a keyword/marker
on all function invocations.
:arg marker: a :py:class:`_pytest.mark.MarkDecorator` object
created by a call to ``pytest.mark.NAME(...)``.
"""
try:
self.node.keywords[marker.markname] = marker
except AttributeError:
raise ValueError(marker)
def raiseerror(self, msg):
""" raise a FixtureLookupError with the given message. """
raise self._fixturemanager.FixtureLookupError(None, self, msg)
def _fillfixtures(self):
item = self._pyfuncitem
fixturenames = getattr(item, "fixturenames", self.fixturenames)
for argname in fixturenames:
if argname not in item.funcargs:
item.funcargs[argname] = self.getfixturevalue(argname)
def cached_setup(self, setup, teardown=None, scope="module", extrakey=None):
""" (deprecated) Return a testing resource managed by ``setup`` &
``teardown`` calls. ``scope`` and ``extrakey`` determine when the
``teardown`` function will be called so that subsequent calls to
``setup`` would recreate the resource. With pytest-2.3 you often
do not need ``cached_setup()`` as you can directly declare a scope
on a fixture function and register a finalizer through
``request.addfinalizer()``.
:arg teardown: function receiving a previously setup resource.
:arg setup: a no-argument function creating a resource.
:arg scope: a string value out of ``function``, ``class``, ``module``
or ``session`` indicating the caching lifecycle of the resource.
:arg extrakey: added to internal caching key of (funcargname, scope).
"""
if not hasattr(self.config, '_setupcache'):
self.config._setupcache = {} # XXX weakref?
cachekey = (self.fixturename, self._getscopeitem(scope), extrakey)
cache = self.config._setupcache
try:
val = cache[cachekey]
except KeyError:
self._check_scope(self.fixturename, self.scope, scope)
val = setup()
cache[cachekey] = val
if teardown is not None:
def finalizer():
del cache[cachekey]
teardown(val)
self._addfinalizer(finalizer, scope=scope)
return val
def getfixturevalue(self, argname):
""" Dynamically run a named fixture function.
Declaring fixtures via function argument is recommended where possible.
But if you can only decide whether to use another fixture at test
setup time, you may use this function to retrieve it inside a fixture
or test function body.
"""
return self._get_active_fixturedef(argname).cached_result[0]
def getfuncargvalue(self, argname):
""" Deprecated, use getfixturevalue. """
from _pytest import deprecated
warnings.warn(
deprecated.GETFUNCARGVALUE,
DeprecationWarning)
return self.getfixturevalue(argname)
def _get_active_fixturedef(self, argname):
try:
return self._fixture_defs[argname]
except KeyError:
try:
fixturedef = self._getnextfixturedef(argname)
except FixtureLookupError:
if argname == "request":
class PseudoFixtureDef:
cached_result = (self, [0], None)
scope = "function"
return PseudoFixtureDef
raise
# remove indent to prevent the python3 exception
# from leaking into the call
result = self._getfixturevalue(fixturedef)
self._fixture_values[argname] = result
self._fixture_defs[argname] = fixturedef
return fixturedef
def _get_fixturestack(self):
current = self
l = []
while 1:
fixturedef = getattr(current, "_fixturedef", None)
if fixturedef is None:
l.reverse()
return l
l.append(fixturedef)
current = current._parent_request
def _getfixturevalue(self, fixturedef):
# prepare a subrequest object before calling fixture function
# (latter managed by fixturedef)
argname = fixturedef.argname
funcitem = self._pyfuncitem
scope = fixturedef.scope
try:
param = funcitem.callspec.getparam(argname)
except (AttributeError, ValueError):
param = NOTSET
param_index = 0
if fixturedef.params is not None:
frame = inspect.stack()[3]
frameinfo = inspect.getframeinfo(frame[0])
source_path = frameinfo.filename
source_lineno = frameinfo.lineno
source_path = py.path.local(source_path)
if source_path.relto(funcitem.config.rootdir):
source_path = source_path.relto(funcitem.config.rootdir)
msg = (
"The requested fixture has no parameter defined for the "
"current test.\n\nRequested fixture '{0}' defined in:\n{1}"
"\n\nRequested here:\n{2}:{3}".format(
fixturedef.argname,
getlocation(fixturedef.func, funcitem.config.rootdir),
source_path,
source_lineno,
)
)
pytest.fail(msg)
else:
# indices might not be set if old-style metafunc.addcall() was used
param_index = funcitem.callspec.indices.get(argname, 0)
# if a parametrize invocation set a scope it will override
# the static scope defined with the fixture function
paramscopenum = funcitem.callspec._arg2scopenum.get(argname)
if paramscopenum is not None:
scope = scopes[paramscopenum]
subrequest = SubRequest(self, scope, param, param_index, fixturedef)
# check if a higher-level scoped fixture accesses a lower level one
subrequest._check_scope(argname, self.scope, scope)
# clear sys.exc_info before invoking the fixture (python bug?)
# if its not explicitly cleared it will leak into the call
exc_clear()
try:
# call the fixture function
val = fixturedef.execute(request=subrequest)
finally:
# if fixture function failed it might have registered finalizers
self.session._setupstate.addfinalizer(fixturedef.finish,
subrequest.node)
return val
def _check_scope(self, argname, invoking_scope, requested_scope):
if argname == "request":
return
if scopemismatch(invoking_scope, requested_scope):
# try to report something helpful
lines = self._factorytraceback()
pytest.fail("ScopeMismatch: You tried to access the %r scoped "
"fixture %r with a %r scoped request object, "
"involved factories\n%s" %(
(requested_scope, argname, invoking_scope, "\n".join(lines))),
pytrace=False)
def _factorytraceback(self):
lines = []
for fixturedef in self._get_fixturestack():
factory = fixturedef.func
fs, lineno = getfslineno(factory)
p = self._pyfuncitem.session.fspath.bestrelpath(fs)
args = _format_args(factory)
lines.append("%s:%d: def %s%s" %(
p, lineno, factory.__name__, args))
return lines
def _getscopeitem(self, scope):
if scope == "function":
# this might also be a non-function Item despite its attribute name
return self._pyfuncitem
node = get_scope_node(self._pyfuncitem, scope)
if node is None and scope == "class":
# fallback to function item itself
node = self._pyfuncitem
assert node
return node
def __repr__(self):
return "<FixtureRequest for %r>" %(self.node)
class SubRequest(FixtureRequest):
""" a sub request for handling getting a fixture from a
test function/fixture. """
def __init__(self, request, scope, param, param_index, fixturedef):
self._parent_request = request
self.fixturename = fixturedef.argname
if param is not NOTSET:
self.param = param
self.param_index = param_index
self.scope = scope
self._fixturedef = fixturedef
self.addfinalizer = fixturedef.addfinalizer
self._pyfuncitem = request._pyfuncitem
self._fixture_values = request._fixture_values
self._fixture_defs = request._fixture_defs
self._arg2fixturedefs = request._arg2fixturedefs
self._arg2index = request._arg2index
self._fixturemanager = request._fixturemanager
def __repr__(self):
return "<SubRequest %r for %r>" % (self.fixturename, self._pyfuncitem)
class ScopeMismatchError(Exception):
""" A fixture function tries to use a different fixture function which
which has a lower scope (e.g. a Session one calls a function one)
"""
scopes = "session module class function".split()
scopenum_function = scopes.index("function")
def scopemismatch(currentscope, newscope):
return scopes.index(newscope) > scopes.index(currentscope)
def scope2index(scope, descr, where=None):
"""Look up the index of ``scope`` and raise a descriptive value error
if not defined.
"""
try:
return scopes.index(scope)
except ValueError:
raise ValueError(
"{0} {1}has an unsupported scope value '{2}'".format(
descr, 'from {0} '.format(where) if where else '',
scope)
)
class FixtureLookupError(LookupError):
""" could not return a requested Fixture (missing or invalid). """
def __init__(self, argname, request, msg=None):
self.argname = argname
self.request = request
self.fixturestack = request._get_fixturestack()
self.msg = msg
def formatrepr(self):
tblines = []
addline = tblines.append
stack = [self.request._pyfuncitem.obj]
stack.extend(map(lambda x: x.func, self.fixturestack))
msg = self.msg
if msg is not None:
# the last fixture raise an error, let's present
# it at the requesting side
stack = stack[:-1]
for function in stack:
fspath, lineno = getfslineno(function)
try:
lines, _ = inspect.getsourcelines(get_real_func(function))
except (IOError, IndexError, TypeError):
error_msg = "file %s, line %s: source code not available"
addline(error_msg % (fspath, lineno+1))
else:
addline("file %s, line %s" % (fspath, lineno+1))
for i, line in enumerate(lines):
line = line.rstrip()
addline(" " + line)
if line.lstrip().startswith('def'):
break
if msg is None:
fm = self.request._fixturemanager
available = []
parentid = self.request._pyfuncitem.parent.nodeid
for name, fixturedefs in fm._arg2fixturedefs.items():
faclist = list(fm._matchfactories(fixturedefs, parentid))
if faclist and name not in available:
available.append(name)
msg = "fixture %r not found" % (self.argname,)
msg += "\n available fixtures: %s" %(", ".join(sorted(available)),)
msg += "\n use 'pytest --fixtures [testpath]' for help on them."
return FixtureLookupErrorRepr(fspath, lineno, tblines, msg, self.argname)
class FixtureLookupErrorRepr(TerminalRepr):
def __init__(self, filename, firstlineno, tblines, errorstring, argname):
self.tblines = tblines
self.errorstring = errorstring
self.filename = filename
self.firstlineno = firstlineno
self.argname = argname
def toterminal(self, tw):
# tw.line("FixtureLookupError: %s" %(self.argname), red=True)
for tbline in self.tblines:
tw.line(tbline.rstrip())
lines = self.errorstring.split("\n")
if lines:
tw.line('{0} {1}'.format(FormattedExcinfo.fail_marker,
lines[0].strip()), red=True)
for line in lines[1:]:
tw.line('{0} {1}'.format(FormattedExcinfo.flow_marker,
line.strip()), red=True)
tw.line()
tw.line("%s:%d" % (self.filename, self.firstlineno+1))
def fail_fixturefunc(fixturefunc, msg):
fs, lineno = getfslineno(fixturefunc)
location = "%s:%s" % (fs, lineno+1)
source = _pytest._code.Source(fixturefunc)
pytest.fail(msg + ":\n\n" + str(source.indent()) + "\n" + location,
pytrace=False)
def call_fixture_func(fixturefunc, request, kwargs):
yieldctx = is_generator(fixturefunc)
if yieldctx:
it = fixturefunc(**kwargs)
res = next(it)
def teardown():
try:
next(it)
except StopIteration:
pass
else:
fail_fixturefunc(fixturefunc,
"yield_fixture function has more than one 'yield'")
request.addfinalizer(teardown)
else:
res = fixturefunc(**kwargs)
return res
class FixtureDef:
""" A container for a factory definition. """
def __init__(self, fixturemanager, baseid, argname, func, scope, params,
unittest=False, ids=None):
self._fixturemanager = fixturemanager
self.baseid = baseid or ''
self.has_location = baseid is not None
self.func = func
self.argname = argname
self.scope = scope
self.scopenum = scope2index(
scope or "function",
descr='fixture {0}'.format(func.__name__),
where=baseid
)
self.params = params
startindex = unittest and 1 or None
self.argnames = getfuncargnames(func, startindex=startindex)
self.unittest = unittest
self.ids = ids
self._finalizer = []
def addfinalizer(self, finalizer):
self._finalizer.append(finalizer)
def finish(self):
try:
while self._finalizer:
func = self._finalizer.pop()
func()
finally:
ihook = self._fixturemanager.session.ihook
ihook.pytest_fixture_post_finalizer(fixturedef=self)
# even if finalization fails, we invalidate
# the cached fixture value
if hasattr(self, "cached_result"):
del self.cached_result
def execute(self, request):
# get required arguments and register our own finish()
# with their finalization
for argname in self.argnames:
fixturedef = request._get_active_fixturedef(argname)
if argname != "request":
fixturedef.addfinalizer(self.finish)
my_cache_key = request.param_index
cached_result = getattr(self, "cached_result", None)
if cached_result is not None:
result, cache_key, err = cached_result
if my_cache_key == cache_key:
if err is not None:
py.builtin._reraise(*err)
else:
return result
# we have a previous but differently parametrized fixture instance
# so we need to tear it down before creating a new one
self.finish()
assert not hasattr(self, "cached_result")
ihook = self._fixturemanager.session.ihook
return ihook.pytest_fixture_setup(fixturedef=self, request=request)
def __repr__(self):
return ("<FixtureDef name=%r scope=%r baseid=%r >" %
(self.argname, self.scope, self.baseid))
def pytest_fixture_setup(fixturedef, request):
""" Execution of fixture setup. """
kwargs = {}
for argname in fixturedef.argnames:
fixdef = request._get_active_fixturedef(argname)
result, arg_cache_key, exc = fixdef.cached_result
request._check_scope(argname, request.scope, fixdef.scope)
kwargs[argname] = result
fixturefunc = fixturedef.func
if fixturedef.unittest:
if request.instance is not None:
# bind the unbound method to the TestCase instance
fixturefunc = fixturedef.func.__get__(request.instance)
else:
# the fixture function needs to be bound to the actual
# request.instance so that code working with "fixturedef" behaves
# as expected.
if request.instance is not None:
fixturefunc = getimfunc(fixturedef.func)
if fixturefunc != fixturedef.func:
fixturefunc = fixturefunc.__get__(request.instance)
my_cache_key = request.param_index
try:
result = call_fixture_func(fixturefunc, request, kwargs)
except Exception:
fixturedef.cached_result = (None, my_cache_key, sys.exc_info())
raise
fixturedef.cached_result = (result, my_cache_key, None)
return result
class FixtureFunctionMarker:
def __init__(self, scope, params, autouse=False, ids=None, name=None):
self.scope = scope
self.params = params
self.autouse = autouse
self.ids = ids
self.name = name
def __call__(self, function):
if isclass(function):
raise ValueError(
"class fixtures not supported (may be in the future)")
function._pytestfixturefunction = self
return function
def fixture(scope="function", params=None, autouse=False, ids=None, name=None):
""" (return a) decorator to mark a fixture factory function.
This decorator can be used (with or or without parameters) to define
a fixture function. The name of the fixture function can later be
referenced to cause its invocation ahead of running tests: test
modules or classes can use the pytest.mark.usefixtures(fixturename)
marker. Test functions can directly use fixture names as input
arguments in which case the fixture instance returned from the fixture
function will be injected.
:arg scope: the scope for which this fixture is shared, one of
"function" (default), "class", "module" or "session".
:arg params: an optional list of parameters which will cause multiple
invocations of the fixture function and all of the tests
using it.
:arg autouse: if True, the fixture func is activated for all tests that
can see it. If False (the default) then an explicit
reference is needed to activate the fixture.
:arg ids: list of string ids each corresponding to the params
so that they are part of the test id. If no ids are provided
they will be generated automatically from the params.
:arg name: the name of the fixture. This defaults to the name of the
decorated function. If a fixture is used in the same module in
which it is defined, the function name of the fixture will be
shadowed by the function arg that requests the fixture; one way
to resolve this is to name the decorated function
``fixture_<fixturename>`` and then use
``@pytest.fixture(name='<fixturename>')``.
Fixtures can optionally provide their values to test functions using a ``yield`` statement,
instead of ``return``. In this case, the code block after the ``yield`` statement is executed
as teardown code regardless of the test outcome. A fixture function must yield exactly once.
"""
if callable(scope) and params is None and autouse == False:
# direct decoration
return FixtureFunctionMarker(
"function", params, autouse, name=name)(scope)
if params is not None and not isinstance(params, (list, tuple)):
params = list(params)
return FixtureFunctionMarker(scope, params, autouse, ids=ids, name=name)
def yield_fixture(scope="function", params=None, autouse=False, ids=None, name=None):
""" (return a) decorator to mark a yield-fixture factory function.
.. deprecated:: 3.0
Use :py:func:`pytest.fixture` directly instead.
"""
if callable(scope) and params is None and not autouse:
# direct decoration
return FixtureFunctionMarker(
"function", params, autouse, ids=ids, name=name)(scope)
else:
return FixtureFunctionMarker(scope, params, autouse, ids=ids, name=name)
defaultfuncargprefixmarker = fixture()
@fixture(scope="session")
def pytestconfig(request):
""" the pytest config object with access to command line opts."""
return request.config
class FixtureManager:
"""
pytest fixtures definitions and information is stored and managed
from this class.
During collection fm.parsefactories() is called multiple times to parse
fixture function definitions into FixtureDef objects and internal
data structures.
During collection of test functions, metafunc-mechanics instantiate
a FuncFixtureInfo object which is cached per node/func-name.
This FuncFixtureInfo object is later retrieved by Function nodes
which themselves offer a fixturenames attribute.
The FuncFixtureInfo object holds information about fixtures and FixtureDefs
relevant for a particular function. An initial list of fixtures is
assembled like this:
- ini-defined usefixtures
- autouse-marked fixtures along the collection chain up from the function
- usefixtures markers at module/class/function level
- test function funcargs
Subsequently the funcfixtureinfo.fixturenames attribute is computed
as the closure of the fixtures needed to setup the initial fixtures,
i. e. fixtures needed by fixture functions themselves are appended
to the fixturenames list.
Upon the test-setup phases all fixturenames are instantiated, retrieved
by a lookup of their FuncFixtureInfo.
"""
_argprefix = "pytest_funcarg__"
FixtureLookupError = FixtureLookupError
FixtureLookupErrorRepr = FixtureLookupErrorRepr
def __init__(self, session):
self.session = session
self.config = session.config
self._arg2fixturedefs = {}
self._holderobjseen = set()
self._arg2finish = {}
self._nodeid_and_autousenames = [("", self.config.getini("usefixtures"))]
session.config.pluginmanager.register(self, "funcmanage")
def getfixtureinfo(self, node, func, cls, funcargs=True):
if funcargs and not hasattr(node, "nofuncargs"):
if cls is not None:
startindex = 1
else:
startindex = None
argnames = getfuncargnames(func, startindex)
else:
argnames = ()
usefixtures = getattr(func, "usefixtures", None)
initialnames = argnames
if usefixtures is not None:
initialnames = usefixtures.args + initialnames
fm = node.session._fixturemanager
names_closure, arg2fixturedefs = fm.getfixtureclosure(initialnames,
node)
return FuncFixtureInfo(argnames, names_closure, arg2fixturedefs)
def pytest_plugin_registered(self, plugin):
nodeid = None
try:
p = py.path.local(plugin.__file__)
except AttributeError:
pass
else:
# construct the base nodeid which is later used to check
# what fixtures are visible for particular tests (as denoted
# by their test id)
if p.basename.startswith("conftest.py"):
nodeid = p.dirpath().relto(self.config.rootdir)
if p.sep != "/":
nodeid = nodeid.replace(p.sep, "/")
self.parsefactories(plugin, nodeid)
def _getautousenames(self, nodeid):
""" return a tuple of fixture names to be used. """
autousenames = []
for baseid, basenames in self._nodeid_and_autousenames:
if nodeid.startswith(baseid):
if baseid:
i = len(baseid)
nextchar = nodeid[i:i+1]
if nextchar and nextchar not in ":/":
continue
autousenames.extend(basenames)
# make sure autousenames are sorted by scope, scopenum 0 is session
autousenames.sort(
key=lambda x: self._arg2fixturedefs[x][-1].scopenum)
return autousenames
def getfixtureclosure(self, fixturenames, parentnode):
# collect the closure of all fixtures , starting with the given
# fixturenames as the initial set. As we have to visit all
# factory definitions anyway, we also return a arg2fixturedefs
# mapping so that the caller can reuse it and does not have
# to re-discover fixturedefs again for each fixturename
# (discovering matching fixtures for a given name/node is expensive)
parentid = parentnode.nodeid
fixturenames_closure = self._getautousenames(parentid)
def merge(otherlist):
for arg in otherlist:
if arg not in fixturenames_closure:
fixturenames_closure.append(arg)
merge(fixturenames)
arg2fixturedefs = {}
lastlen = -1
while lastlen != len(fixturenames_closure):
lastlen = len(fixturenames_closure)
for argname in fixturenames_closure:
if argname in arg2fixturedefs:
continue
fixturedefs = self.getfixturedefs(argname, parentid)
if fixturedefs:
arg2fixturedefs[argname] = fixturedefs
merge(fixturedefs[-1].argnames)
return fixturenames_closure, arg2fixturedefs
def pytest_generate_tests(self, metafunc):
for argname in metafunc.fixturenames:
faclist = metafunc._arg2fixturedefs.get(argname)
if faclist:
fixturedef = faclist[-1]
if fixturedef.params is not None:
func_params = getattr(getattr(metafunc.function, 'parametrize', None), 'args', [[None]])
# skip directly parametrized arguments
argnames = func_params[0]
if not isinstance(argnames, (tuple, list)):
argnames = [x.strip() for x in argnames.split(",") if x.strip()]
if argname not in func_params and argname not in argnames:
metafunc.parametrize(argname, fixturedef.params,
indirect=True, scope=fixturedef.scope,
ids=fixturedef.ids)
else:
continue # will raise FixtureLookupError at setup time
def pytest_collection_modifyitems(self, items):
# separate parametrized setups
items[:] = reorder_items(items)
def parsefactories(self, node_or_obj, nodeid=NOTSET, unittest=False):
if nodeid is not NOTSET:
holderobj = node_or_obj
else:
holderobj = node_or_obj.obj
nodeid = node_or_obj.nodeid
if holderobj in self._holderobjseen:
return
self._holderobjseen.add(holderobj)
autousenames = []
for name in dir(holderobj):
obj = getattr(holderobj, name, None)
# fixture functions have a pytest_funcarg__ prefix (pre-2.3 style)
# or are "@pytest.fixture" marked
marker = getfixturemarker(obj)
if marker is None:
if not name.startswith(self._argprefix):
continue
if not callable(obj):
continue
marker = defaultfuncargprefixmarker
from _pytest import deprecated
self.config.warn('C1', deprecated.FUNCARG_PREFIX.format(name=name))
name = name[len(self._argprefix):]
elif not isinstance(marker, FixtureFunctionMarker):
# magic globals with __getattr__ might have got us a wrong
# fixture attribute
continue
else:
if marker.name:
name = marker.name
msg = 'fixtures cannot have "pytest_funcarg__" prefix ' \
'and be decorated with @pytest.fixture:\n%s' % name
assert not name.startswith(self._argprefix), msg
fixture_def = FixtureDef(self, nodeid, name, obj,
marker.scope, marker.params,
unittest=unittest, ids=marker.ids)
faclist = self._arg2fixturedefs.setdefault(name, [])
if fixture_def.has_location:
faclist.append(fixture_def)
else:
# fixturedefs with no location are at the front
# so this inserts the current fixturedef after the
# existing fixturedefs from external plugins but
# before the fixturedefs provided in conftests.
i = len([f for f in faclist if not f.has_location])
faclist.insert(i, fixture_def)
if marker.autouse:
autousenames.append(name)
if autousenames:
self._nodeid_and_autousenames.append((nodeid or '', autousenames))
def getfixturedefs(self, argname, nodeid):
"""
Gets a list of fixtures which are applicable to the given node id.
:param str argname: name of the fixture to search for
:param str nodeid: full node id of the requesting test.
:return: list[FixtureDef]
"""
try:
fixturedefs = self._arg2fixturedefs[argname]
except KeyError:
return None
else:
return tuple(self._matchfactories(fixturedefs, nodeid))
def _matchfactories(self, fixturedefs, nodeid):
for fixturedef in fixturedefs:
if nodeid.startswith(fixturedef.baseid):
yield fixturedef