diff options
| -rw-r--r-- | Doc/library/unittest.mock-examples.rst | 50 | ||||
| -rw-r--r-- | Doc/library/unittest.mock.rst | 14 | ||||
| -rw-r--r-- | Lib/unittest/mock.py | 10 | ||||
| -rw-r--r-- | Lib/unittest/test/testmock/testmock.py | 10 |
4 files changed, 31 insertions, 53 deletions
diff --git a/Doc/library/unittest.mock-examples.rst b/Doc/library/unittest.mock-examples.rst index 0fc32d2..8e1e88a 100644 --- a/Doc/library/unittest.mock-examples.rst +++ b/Doc/library/unittest.mock-examples.rst @@ -838,56 +838,6 @@ and the `return_value` will use your subclass automatically. That means all children of a `CopyingMock` will also have the type `CopyingMock`. -Multiple calls with different effects -------------------------------------- - -Handling code that needs to behave differently on subsequent calls during the -test can be tricky. For example you may have a function that needs to raise -an exception the first time it is called but returns a response on the second -call (testing retry behaviour). - -One approach is to use a :attr:`side_effect` function that replaces itself. The -first time it is called the `side_effect` sets a new `side_effect` that will -be used for the second call. It then raises an exception: - - >>> def side_effect(*args): - ... def second_call(*args): - ... return 'response' - ... mock.side_effect = second_call - ... raise Exception('boom') - ... - >>> mock = Mock(side_effect=side_effect) - >>> mock('first') - Traceback (most recent call last): - ... - Exception: boom - >>> mock('second') - 'response' - >>> mock.assert_called_with('second') - -Another perfectly valid way would be to pop return values from a list. If the -return value is an exception, raise it instead of returning it: - - >>> returns = [Exception('boom'), 'response'] - >>> def side_effect(*args): - ... result = returns.pop(0) - ... if isinstance(result, Exception): - ... raise result - ... return result - ... - >>> mock = Mock(side_effect=side_effect) - >>> mock('first') - Traceback (most recent call last): - ... - Exception: boom - >>> mock('second') - 'response' - >>> mock.assert_called_with('second') - -Which approach you prefer is a matter of taste. The first approach is actually -a line shorter but maybe the second approach is more readable. - - Nesting Patches --------------- diff --git a/Doc/library/unittest.mock.rst b/Doc/library/unittest.mock.rst index ed6775a..12b0275 100644 --- a/Doc/library/unittest.mock.rst +++ b/Doc/library/unittest.mock.rst @@ -823,6 +823,20 @@ a `StopIteration` is raised): ... StopIteration +If any members of the iterable are exceptions they will be raised instead of +returned:: + + >>> iterable = (33, ValueError, 66) + >>> m = MagicMock(side_effect=iterable) + >>> m() + 33 + >>> m() + Traceback (most recent call last): + ... + ValueError + >>> m() + 66 + .. _deleting-attributes: diff --git a/Lib/unittest/mock.py b/Lib/unittest/mock.py index 8cedcb4..8378b0f 100644 --- a/Lib/unittest/mock.py +++ b/Lib/unittest/mock.py @@ -891,7 +891,10 @@ class CallableMixin(Base): raise effect if not _callable(effect): - return next(effect) + result = next(effect) + if _is_exception(result): + raise result + return result ret_val = effect(*args, **kwargs) if ret_val is DEFAULT: @@ -931,8 +934,9 @@ class Mock(CallableMixin, NonCallableMock): arguments as the mock, and unless it returns `DEFAULT`, the return value of this function is used as the return value. - Alternatively `side_effect` can be an exception class or instance. In - this case the exception will be raised when the mock is called. + If `side_effect` is an iterable then each call to the mock will return + the next value from the iterable. If any of the members of the iterable + are exceptions they will be raised instead of returned. If `side_effect` is an iterable then each call to the mock will return the next value from the iterable. diff --git a/Lib/unittest/test/testmock/testmock.py b/Lib/unittest/test/testmock/testmock.py index ae9822e..64fd1a1 100644 --- a/Lib/unittest/test/testmock/testmock.py +++ b/Lib/unittest/test/testmock/testmock.py @@ -868,6 +868,16 @@ class MockTest(unittest.TestCase): self.assertRaises(StopIteration, mock) + def test_side_effect_iterator_exceptions(self): + for Klass in Mock, MagicMock: + iterable = (ValueError, 3, KeyError, 6) + m = Klass(side_effect=iterable) + self.assertRaises(ValueError, m) + self.assertEqual(m(), 3) + self.assertRaises(KeyError, m) + self.assertEqual(m(), 6) + + def test_side_effect_setting_iterator(self): mock = Mock() mock.side_effect = iter([1, 2, 3]) |