简言之
在Flask SqlAlchemy中测试模型类时，如何模拟方法.query.filter_by()，以便返回模拟模型对象的列表？
全部细节
假设我们有一个如下代码所示的模型类from flask.ext.sqlalchemy import SQLAlchemy
db = SQLAlchemy()
class SomeModel(db.Model):
# more column mapping and methods go here
然后在我们的烧瓶代码中我们调用SomeModel.query.filter_by(...)
在我们的测试代码中，将Python unittest模型与mocking一起使用，我们希望模拟filter_by()调用，以便它在我们设计的测试用例下返回模型对象列表。
我们怎么才能做到？
附则
我的google搜索只找到了this related post；尽管在类的开头应用@patch("flask_sqlalchemy.SignallingSession", autospec=True)对我不起作用。
我还尝试将函数模拟为下面的代码片段@patch('app.model.some_model.SomeModel.query.filter_by')
def test_some_case(self, filterbyMOCK):
# more test logic goes here
启动时代码立即出错RuntimeError: application not registered on db instance and no application bound to current context
下面是来自PyCharm IDE的完整错误快照。Traceback (most recent call last):
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/mock/mock.py", line 1297, in patched
arg = patching.__enter__()
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/mock/mock.py", line 1353, in __enter__
self.target = self.getter()
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/mock/mock.py", line 1523, in
getter = lambda: _importer(target)
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/mock/mock.py", line 1210, in _importer
thing = _dot_lookup(thing, comp, import_path)
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/mock/mock.py", line 1197, in _dot_lookup
return getattr(thing, comp)
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 428, in __get__
return type.query_class(mapper, session=self.sa.session())
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/sqlalchemy/orm/scoping.py", line 78, in __call__
return self.registry()
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/sqlalchemy/util/_collections.py", line 990, in __call__
return self.registry.setdefault(key, self.createfunc())
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 136, in __init__
self.app = db.get_app()
File "/home/namgivu/NN/code/someproject-cloud/venv/local/lib/python2.7/site-packages/flask_sqlalchemy/__init__.py", line 809, in get_app
raise RuntimeError('application not registered on db '
RuntimeError: application not registered on db instance and no application bound to current context