使用 Pytest 和 Mock 测试查询数据库的视图
Using Pytest and Mock to test view that queries database
我正在尝试为我的 Django 应用程序使用的视图编写单元测试。视图本身通过自定义模型(下面视图的代码片段)从数据库中获取数据。
views.py
def calibrator_data(calid,code):
data = []
sources, times = zip(*DataSource.objects.filter(event__name=code).values_list('id','timestamp').order_by('timestamp'))
points = Datapoint.objects.filter(data__in=sources)
people = Decision.objects.filter(source__id=calid,planet__name=code,value='D',current=True).values_list('person__username',flat=True).distinct()
norm = dict((key,0) for key in sources)
for pid in people:
cal = []
sc = dict(points.filter(user__username=pid,pointtype='S').values_list('data__id','value'))
bg = dict(points.filter(user__username=pid,pointtype='B').values_list('data__id','value'))
c = dict(points.filter(user__username=pid,pointtype='C',coorder__source__id=calid).values_list('data__id','value'))
sc_norm = dict(norm.items() + sc.items())
bg_norm = dict(norm.items() + bg.items())
c_norm = dict(norm.items() + c.items())
for v in sources:
try:
cal.append((sc_norm[v]- bg_norm[v])/(c_norm[v] - bg_norm[v]))
except:
cal.append(0)
data.append(cal)
return data,[timegm(s.timetuple())+1e-6*s.microsecond for s in times],list(people)
以及我尝试编写的测试。
test_reduc.py
pytestmark = pytest.mark.django_db
@pytest.mark.django_db
class TestDataReduction(TestCase):
pytestmark = pytest.mark.django_db
################################################################################
############################ Testing calibrator_data ###########################
################################################################################
def test_calibrator_data(self):
mock_source = MagicMock(spec=DataSource)
mock_times = MagicMock(spec=DataSource)
mock_source.return_value = array([random.randint(0,10)])
mock_times.return_value = datetime.now()
mock_points = MagicMock(spec=Datapoint)
mock_points.user = []
mock_people = MagicMock(spec=Decision)
mock_people.data = []
calid = 22
code = 'corot2b'
self.output = calibrator_data(calid,code)
assert type(self.output[0])==type([])
测试一直失败并出现错误:
=============================================== test session starts ===============================================
platform darwin -- Python 2.7.10 -- py-1.4.30 -- pytest-2.7.2
rootdir: /Users/tomasjames/Documents/citsciportal/app, inifile: pytest.ini
plugins: django
collected 1 items
agentex/tests/test_reduc.py F
==================================================== FAILURES =====================================================
_____________________________________ TestDataReduction.test_calibrator_data ______________________________________
self = <agentex.tests.test_reduc.TestDataReduction testMethod=test_calibrator_data>
def test_calibrator_data(self):
mock_source = MagicMock(spec=DataSource)
mock_times = MagicMock(spec=DataSource)
mock_source.return_value = array([random.randint(0,10)])
mock_times.return_value = datetime.now()
mock_points = MagicMock(spec=Datapoint)
mock_points.user = []
mock_people = MagicMock(spec=Decision)
mock_people.data = []
calid = 22
code = 'corot2b'
> self.output = calibrator_data(calid,code)
agentex/tests/test_reduc.py:51:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
calid = 22, code = 'corot2b'
def calibrator_data(calid,code):
data = []
> sources, times = zip(*DataSource.objects.filter(event__name=code).values_list('id','timestamp').order_by('timestamp'))
E ValueError: need more than 0 values to unpack
agentex/datareduc.py:56: ValueError
============================================ 1 failed in 7.69 seconds =============================================
这是我第一次尝试编写任何类型的测试(正如您可能看到的那样),这是一个具有挑战性的测试。我认为错误的产生是因为 views.py 仍在尝试访问测试环境中的数据库(使用空白数据库运行)——时间似乎证实了这一点。然而,我尝试模拟变量源、时间、点和人似乎没有奏效。我试图将它们分配给我知道数据库查询产生的变量,以节省必须模拟整个 database/QuerySet。
这是执行测试的错误方法吗?我找不到哪里出错了。
提前致谢!
您错过了使用 mock 覆盖方法的一个关键组成部分。你需要使用 mock 作为方法装饰器来基本上猴子匹配你的方法才能做你想做的事。
你会想写一些像这样的东西。 (注意:根本没有测试过,但应该会引导您朝着正确的方向前进)。
@pytest.mark.django_db
class TestDataReduction(TestCase):
@mock.patch(your_module.xyz.DataSource)
@mock.patch(your_module.xyz.Datapoint)
@mock.patch(your_module.xyz.Decision)
def test_calibrator_data(self, mock_source, mock_points,
mock_people):
mock_source.objects.filter.return_value.values.return_value.order_by.return_value = [array([random.randint(0,10)]), datetime.now()]
mock_points.objects.filter.return_value = []
mock_people.objects.filter.values_list.return_value.distinct.return_value = []
calid = 22
code = 'corot2b'
self.output = calibrator_data(calid,code)
assert type(self.output[0])==type([])
您还需要模拟任何您想要的 return 值作为对 points.filter
的多次调用。一种方法是使用副作用。这里有一个很好的例子:
除了你已经看过的我的 post(https://www.chicagodjango.com/blog/quick-introduction-mock/), there is more information about using mock.patch
in this blog post: http://fgimian.github.io/blog/2014/04/10/using-the-python-mock-library-to-fake-regular-functions-during-tests/
我正在尝试为我的 Django 应用程序使用的视图编写单元测试。视图本身通过自定义模型(下面视图的代码片段)从数据库中获取数据。
views.py
def calibrator_data(calid,code):
data = []
sources, times = zip(*DataSource.objects.filter(event__name=code).values_list('id','timestamp').order_by('timestamp'))
points = Datapoint.objects.filter(data__in=sources)
people = Decision.objects.filter(source__id=calid,planet__name=code,value='D',current=True).values_list('person__username',flat=True).distinct()
norm = dict((key,0) for key in sources)
for pid in people:
cal = []
sc = dict(points.filter(user__username=pid,pointtype='S').values_list('data__id','value'))
bg = dict(points.filter(user__username=pid,pointtype='B').values_list('data__id','value'))
c = dict(points.filter(user__username=pid,pointtype='C',coorder__source__id=calid).values_list('data__id','value'))
sc_norm = dict(norm.items() + sc.items())
bg_norm = dict(norm.items() + bg.items())
c_norm = dict(norm.items() + c.items())
for v in sources:
try:
cal.append((sc_norm[v]- bg_norm[v])/(c_norm[v] - bg_norm[v]))
except:
cal.append(0)
data.append(cal)
return data,[timegm(s.timetuple())+1e-6*s.microsecond for s in times],list(people)
以及我尝试编写的测试。
test_reduc.py
pytestmark = pytest.mark.django_db
@pytest.mark.django_db
class TestDataReduction(TestCase):
pytestmark = pytest.mark.django_db
################################################################################
############################ Testing calibrator_data ###########################
################################################################################
def test_calibrator_data(self):
mock_source = MagicMock(spec=DataSource)
mock_times = MagicMock(spec=DataSource)
mock_source.return_value = array([random.randint(0,10)])
mock_times.return_value = datetime.now()
mock_points = MagicMock(spec=Datapoint)
mock_points.user = []
mock_people = MagicMock(spec=Decision)
mock_people.data = []
calid = 22
code = 'corot2b'
self.output = calibrator_data(calid,code)
assert type(self.output[0])==type([])
测试一直失败并出现错误:
=============================================== test session starts ===============================================
platform darwin -- Python 2.7.10 -- py-1.4.30 -- pytest-2.7.2
rootdir: /Users/tomasjames/Documents/citsciportal/app, inifile: pytest.ini
plugins: django
collected 1 items
agentex/tests/test_reduc.py F
==================================================== FAILURES =====================================================
_____________________________________ TestDataReduction.test_calibrator_data ______________________________________
self = <agentex.tests.test_reduc.TestDataReduction testMethod=test_calibrator_data>
def test_calibrator_data(self):
mock_source = MagicMock(spec=DataSource)
mock_times = MagicMock(spec=DataSource)
mock_source.return_value = array([random.randint(0,10)])
mock_times.return_value = datetime.now()
mock_points = MagicMock(spec=Datapoint)
mock_points.user = []
mock_people = MagicMock(spec=Decision)
mock_people.data = []
calid = 22
code = 'corot2b'
> self.output = calibrator_data(calid,code)
agentex/tests/test_reduc.py:51:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
calid = 22, code = 'corot2b'
def calibrator_data(calid,code):
data = []
> sources, times = zip(*DataSource.objects.filter(event__name=code).values_list('id','timestamp').order_by('timestamp'))
E ValueError: need more than 0 values to unpack
agentex/datareduc.py:56: ValueError
============================================ 1 failed in 7.69 seconds =============================================
这是我第一次尝试编写任何类型的测试(正如您可能看到的那样),这是一个具有挑战性的测试。我认为错误的产生是因为 views.py 仍在尝试访问测试环境中的数据库(使用空白数据库运行)——时间似乎证实了这一点。然而,我尝试模拟变量源、时间、点和人似乎没有奏效。我试图将它们分配给我知道数据库查询产生的变量,以节省必须模拟整个 database/QuerySet。
这是执行测试的错误方法吗?我找不到哪里出错了。
提前致谢!
您错过了使用 mock 覆盖方法的一个关键组成部分。你需要使用 mock 作为方法装饰器来基本上猴子匹配你的方法才能做你想做的事。
你会想写一些像这样的东西。 (注意:根本没有测试过,但应该会引导您朝着正确的方向前进)。
@pytest.mark.django_db
class TestDataReduction(TestCase):
@mock.patch(your_module.xyz.DataSource)
@mock.patch(your_module.xyz.Datapoint)
@mock.patch(your_module.xyz.Decision)
def test_calibrator_data(self, mock_source, mock_points,
mock_people):
mock_source.objects.filter.return_value.values.return_value.order_by.return_value = [array([random.randint(0,10)]), datetime.now()]
mock_points.objects.filter.return_value = []
mock_people.objects.filter.values_list.return_value.distinct.return_value = []
calid = 22
code = 'corot2b'
self.output = calibrator_data(calid,code)
assert type(self.output[0])==type([])
您还需要模拟任何您想要的 return 值作为对 points.filter
的多次调用。一种方法是使用副作用。这里有一个很好的例子:
除了你已经看过的我的 post(https://www.chicagodjango.com/blog/quick-introduction-mock/), there is more information about using mock.patch
in this blog post: http://fgimian.github.io/blog/2014/04/10/using-the-python-mock-library-to-fake-regular-functions-during-tests/