编写Pyramid单元测试套件时,对执行SQLAlchemy调用的视图进行单元测试的正确或适当方法是什么。例如:
def my_view(request):
DBSession.query(DeclarativeBase).all()
我是否会使用Mock()
和patch
将DBSession
的范围覆盖到各种类型的DummyDB类中?
答案 0 :(得分:2)
你可以,我很快就会写博客/演讲/提示。这是全新的东西。这是一个预示:
import mock
from sqlalchemy.sql import ClauseElement
class MockSession(mock.MagicMock):
def __init__(self, *arg, **kw):
kw.setdefault('side_effect', self._side_effect)
super(MockSession, self).__init__(*arg, **kw)
self._lookup = {}
def _side_effect(self, *arg, **kw):
if self._mock_return_value is not mock.sentinel.DEFAULT:
return self._mock_return_value
else:
return self._generate(*arg, **kw)
def _get_key(self, arg, kw):
return tuple(self._hash(a) for a in arg) + \
tuple((k, self._hash(kw[k])) for k in sorted(kw))
def _hash(self, arg):
if isinstance(arg, ClauseElement):
expr = str(arg.compile(compile_kwargs={"literal_binds": True}))
return expr
else:
assert hash(arg)
return arg
def _generate(self, *arg, **kw):
key = self._get_key(arg, kw)
if key in self._lookup:
return self._lookup[key]
else:
self._lookup[key] = ret = MockSession()
return ret
if __name__ == '__main__':
from sqlalchemy import Column, Integer
from sqlalchemy.ext.declarative import declarative_base
Base = declarative_base()
class Foo(Base):
__tablename__ = 'foo'
id = Column(Integer, primary_key=True)
x = Column(Integer)
y = Column(Integer)
sess = MockSession()
# write out queries as they would in the code, assign return_value
sess.query(Foo.x).filter(Foo.x == 5).first.return_value = 5
sess.query(Foo.x).filter(Foo.x == 2).first.return_value = 2
sess.query(Foo).filter(Foo.x == 2).filter_by(y=5).all.return_value = [Foo(x=2, y=5)]
sess.query(Foo).filter(Foo.x == 9).all.return_value = [Foo(x=9, y=1), Foo(x=9, y=2)]
# those queries are now replayable and will return what was assigned.
print sess.query(Foo.x).filter(Foo.x == 5).first()
print sess.query(Foo.x).filter(Foo.x == 2).first()
print sess.query(Foo).filter(Foo.x == 2).filter_by(y=5).all()
print sess.query(Foo).filter(Foo.x == 9).all()
我实际上已将此分配到setup / teardown中的全局ScopedSession
,并且它的工作效果令人惊讶:
from myapp.model import MyScopedSession
def setUp(self):
MyScopedSession.registry.set(MockSession())
# set up some queries, we can usually use scoped_session's proxying
MyScopedSession.query(User).filter_by(id=1).first.return_value = User(id=1)
def tearDown(self):
MyScopedSession.remove()
def some_test(self):
# to get at mock methods and accessors, call the scoped_session to get at
# the registry
# ... test some thing
# test a User was added to the session
self.assertEquals(
MyScopedSession().add.mock_calls,
[mock.call(User(name='someuser'))]
)