from contextlib import contextmanager
import inspect
import logging
import six
from nose2.compat import unittest
log = logging.getLogger(__name__)
__unittest = True
@contextmanager
[docs]def A(description):
"""Test scenario context manager.
Returns a :class:`nose2.tools.such.Scenario` instance,
which by convention is bound to ``it``:
.. code-block :: python
with such.A('test scenario') as it:
# tests and fixtures
"""
yield Scenario(description)
class Helper(unittest.TestCase):
def runTest(self):
pass
helper = Helper()
[docs]class Scenario(object):
"""A test scenario.
A test scenario defines a set of fixtures and tests
that depend on those fixtures.
"""
_helper = helper
def __init__(self, description):
self._group = Group('A %s' % description, 0)
@contextmanager
[docs] def having(self, description):
"""Define a new group under the current group.
Fixtures and tests defined within the block will
belong to the new group.
.. code-block :: python
with it.having('a description of this group'):
# ...
"""
last = self._group
self._group = self._group.child(
"having %s" % description)
log.debug("starting new group from %s", description)
yield self
log.debug("leaving group %s", description)
self._group = last
def uses(self, layer):
log.debug("Adding %s as mixin to %s", layer, self._group)
self._group.mixins.append(layer)
[docs] def has_setup(self, func):
"""Add a setup method to this group.
The setup method will run once, before any of the
tests in the containing group.
A group may define any number of setup functions. They
will execute in the order in which they are defined.
.. code-block :: python
@it.has_setup
def setup():
# ...
"""
self._group.addSetup(func)
return func
[docs] def has_teardown(self, func):
"""Add a teardown method to this group.
The teardown method will run once, after all of the
tests in the containing group.
A group may define any number of teardown functions. They
will execute in the order in which they are defined.
.. code-block :: python
@it.has_teardown
def teardown():
# ...
"""
self._group.addTeardown(func)
return func
[docs] def has_test_setup(self, func):
"""Add a test case setup method to this group.
The setup method will run before each of the
tests in the containing group.
A group may define any number of test case setup
functions. They will execute in the order in which they are
defined.
Test setup functions may optionally take one argument. If
they do, they will be passed the :class:`unittest.TestCase`
instance generated for the test.
.. code-block :: python
@it.has_test_setup
def setup(case):
# ...
"""
self._group.addTestSetUp(func)
[docs] def has_test_teardown(self, func):
"""Add a test case teardown method to this group.
The teardown method will run before each of the
tests in the containing group.
A group may define any number of test case teardown
functions. They will execute in the order in which they are
defined.
Test teardown functions may optionally take one argument. If
they do, they will be passed the :class:`unittest.TestCase`
instance generated for the test.
.. code-block :: python
@it.has_test_teardown
def teardown(case):
# ...
"""
self._group.addTestTearDown(func)
[docs] def should(self, desc):
"""Define a test case.
Each function marked with this decorator becomes a test
case in the current group.
The decorator takes one optional argument, the description
of the test case: what it **should** do. If this argument
is not provided, the docstring of the decorated function
will be used as the test case description.
Test functions may optionally take one argument. If they do,
they will be passed the :class:`unittest.TestCase` instance generated
for the test. They can use this TestCase instance to execute assert
methods, among other things.
.. code-block :: python
@it.should('do this')
def dothis(case):
# ....
@it.should
def dothat():
"do that also"
# ....
"""
def decorator(f):
_desc = desc if isinstance(desc, six.string_types) else f.__doc__
case = Case(self._group, f, "should %s" % _desc)
self._group.addCase(case)
return case
if isinstance(desc, type(decorator)):
return decorator(desc)
return decorator
def __getattr__(self, attr):
return getattr(self._helper, attr)
[docs] def createTests(self, mod):
"""Generate test cases for this scenario.
.. warning ::
You must call this, passing in ``globals()``, to
generate tests from the scenario. If you don't
call ``createTests``, **no tests will be
created**.
.. code-block :: python
it.createTests(globals())
"""
self._makeGroupTest(mod, self._group)
def _makeGroupTest(self, mod, group, parent_layer=None, position=0):
layer = self._makeLayer(group, parent_layer, position)
case = self._makeTestCase(group, layer)
log.debug(
"Made test case %s with layer %s from %s", case, layer, group)
mod[layer.__name__] = layer
layer.__module__ = mod['__name__']
mod[case.__name__] = case
case.__module__ = mod['__name__']
for index, child in enumerate(group._children):
self._makeGroupTest(mod, child, layer, index)
def _makeTestCase(self, group, layer):
attr = {
'layer': layer,
'group': group,
'description': group.description,
}
for index, case in enumerate(group._cases):
def _test(s, case=case):
case(s)
name = 'test %04d: %s' % (index, case.description)
_test.__name__ = name
_test.description = case.description
_test.case = case
_test.index = index
attr[name] = _test # for collection and sorting
attr[case.description] = _test # for random access by name
setups = group._test_setups[:]
teardowns = group._test_teardowns[:]
if setups:
def setUp(self):
for func in setups:
args, _, _, _ = inspect.getargspec(func)
if args:
func(self)
else:
func()
attr['setUp'] = setUp
if teardowns:
def tearDown(self):
for func in teardowns:
args, _, _, _ = inspect.getargspec(func)
if args:
func(self)
else:
func()
attr['tearDown'] = tearDown
def methodDescription(self):
return getattr(self, self._testMethodName).description
attr['methodDescription'] = methodDescription
return type(group.description, (unittest.TestCase,), attr)
def _makeLayer(self, group, parent_layer=None, position=0):
if parent_layer is None:
parent_layer = object
# FIXME test setups
# test_setups = group._test_setups[:]
# test_teardowns = group._testeardowns[:]
def setUp(cls):
for setup in cls.setups:
setup()
def tearDown(cls):
for teardown in cls.teardowns:
teardown()
attr = {
'description': group.description,
'setUp': classmethod(setUp),
'tearDown': classmethod(tearDown),
'setups': group._setups[:],
'teardowns': group._teardowns[:],
'position': position,
'mixins': ()
}
if group.base_layer:
# inject this layer into the group class list
# by making it a subclass of parent_layer
layer = group.base_layer
if parent_layer not in layer.__bases__:
layer.mixins = (parent_layer,)
else:
layer = type("%s:layer" % group.description, (parent_layer,), attr)
if group.mixins:
layer.mixins = getattr(layer, 'mixins', ()) + tuple(group.mixins)
log.debug("made layer %s with bases %s and mixins %s",
layer, layer.__bases__, layer.mixins)
return layer
class Group(object):
"""Group of tests w/common fixtures & description"""
def __init__(self, description, indent=0, parent=None, base_layer=None):
self.description = description
self.indent = indent
self.parent = parent
self.base_layer = base_layer
self.mixins = []
self._cases = []
self._setups = []
self._teardowns = []
self._test_setups = []
self._test_teardowns = []
self._children = []
def addCase(self, case):
if not self._cases:
case.first = True
case.indent = self.indent
self._cases.append(case)
def addSetup(self, func):
self._setups.append(func)
def addTeardown(self, func):
self._teardowns.append(func)
def addTestSetUp(self, func):
self._test_setups.append(func)
def addTestTearDown(self, func):
self._test_teardowns.append(func)
def fullDescription(self):
d = []
p = self.parent
while p:
d.insert(0, p.description)
p = p.parent
d.append(self.description)
return ' '.join(d)
def child(self, description, base_layer=None):
child = Group(description, self.indent + 1, self, base_layer)
self._children.append(child)
return child
class Case(object):
"""Information about a test case"""
_helper = helper
def __init__(self, group, func, description):
self.group = group
self.func = func
self.description = description
self._setups = []
self._teardowns = []
self.first = False
self.full = False
def __call__(self, testcase):
# ... only if it takes an arg
self._helper = testcase
args, _, _, _ = inspect.getargspec(self.func)
if args:
self.func(testcase)
else:
self.func()
def __getattr__(self, attr):
return getattr(self._helper, attr)