检查是否已使用不同的参数多次调用函数 [英] Checking whether function has been called multiple times with different parameters

问题描述

假设我们有一个函数f(x,y)和另一个函数

Assume we have a function f(x,y) and another function

def g():
       # ...
       f(i,j) # i,j vary and f is called multiple times
       # ...

我们要编写一个单元测试，以检查是否调用了f的次数并具有正确的参数.

We want to write a Unit test that checks whether f is called the number of times and with the right parameters.

def test_g():
      with patch('mymodule.f') as function:
          assert function.gacs.call_count == correct_no_calls

有

function.assert_called_with(...)

但这仅指最后一次呼叫.因此，假设g依次调用f(1,2)和f(2,3)，则function.assert_called_with(1,2)是False.

but this only refers to the last call. So assuming g calls f(1,2) and then f(2,3), function.assert_called_with(1,2) is False.

此外，还有

function.call_args_list

产生带有正确参数的call对象列表.将此列表与我们在单元测试中创建的call对象进行比较，感觉很麻烦. call似乎是模拟库的内部类.

which yields a list of call objects with the right parameters. Comparing this list to call object that we create in the unit test feels like a very nasty thing to do. call seems like an internal class of the mock library.

是否有更好的方法可以做到这一点?我使用此设置来测试apply函数的并行执行.

Is there a better way to do this? I use this set-up to test parallel execution of an apply function.

推荐答案

即使@MartinPieters的回答也是正确的，我认为这也不是最好的方法.模拟提供 assert_has_calls 这种职责.

Even @MartinPieters's answer is correct I think that is not the best way to do it. Mock provide assert_has_calls to do this kind of duties.

您的测试可能是:

function.assert_has_calls([mock.call(1, 2), mock.call(2, 3)])

mock.call 是帮助类的地方这些工作.

Where mock.call is a helper class do to these kind of jobs.

请注意，这是一个已通话，表示通话列表应在通话列表中，并且不能相等.为了解决这个问题，我通常如下定义自己的助手assert_is_calls()

Pay attention that is a has call and means the call list should be in the list of call and not equal. To solve it I usually define my own helper assert_is_calls() as follow

def assert_is_calls(m, calls, any_order=False):
   assert len(m.mock_calls) == len(calls)
   m.assert_has_calls(calls, any_order=any_order)

那是简历的例子

>>> import mock
>>> f = mock.Mock()
>>> f(1)
<Mock name='mock()' id='139836302999952'>
>>> f(2)
<Mock name='mock()' id='139836302999952'>
>>> f.assert_has_calls([mock.call(1), mock.call(2)])
>>> f.assert_has_calls([mock.call(2), mock.call(1)])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/damico/.local/lib/python2.7/site-packages/mock/mock.py", line 969, in assert_has_calls
    ), cause)
  File "/home/damico/.local/lib/python2.7/site-packages/six.py", line 718, in raise_from
    raise value
AssertionError: Calls not found.
Expected: [call(2), call(1)]
Actual: [call(1), call(2)]
>>> f.assert_has_calls([mock.call(2), mock.call(1)], any_order=True)
>>> f(3)
<Mock name='mock()' id='139836302999952'>
>>> f.assert_has_calls([mock.call(2), mock.call(1)], any_order=True)
>>> f.assert_has_calls([mock.call(1), mock.call(2)])
>>> assert len(f.mock_calls)==2
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AssertionError
>>> assert len(f.mock_calls)==3
>>> def assert_is_calls(m, calls, any_order=False):
...    assert len(m.mock_calls) == len(calls)
...    m.assert_has_calls(calls, any_order=any_order)
... 
>>> assert_is_calls(f, [mock.call(1), mock.call(2), mock.call(3)])
>>> assert_is_calls(f, [mock.call(1), mock.call(3), mock.call(2)])
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 3, in assert_is_calls
  File "/home/damico/.local/lib/python2.7/site-packages/mock/mock.py", line 969, in assert_has_calls
    ), cause)
  File "/home/damico/.local/lib/python2.7/site-packages/six.py", line 718, in raise_from
    raise value
AssertionError: Calls not found.
Expected: [call(1), call(3), call(2)]
Actual: [call(1), call(2), call(3)]
>>> assert_is_calls(f, [mock.call(1), mock.call(3), mock.call(2)], True)
>>> assert_is_calls(f, [mock.call(1), mock.call(3)], True)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 2, in assert_is_calls
AssertionError
>>> 

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