How Do You Set Different Attributes For Different MagicMock Instances In Python?

I'd like to assert that say_name was called with each value in the list name. from unittest.mock import patch class MyClass: def __init__(self, name): self.name = nam

Solution 1:

It is possible to use side_effect to sequentially return values from a mock:

>>> from unittest.mock import Mock
>>> m = Mock()
>>> m.side_effect = ['spam', 123, 'potato']
>>> m()
'spam'
>>> m()
123
>>> m()
'potato'

Applying to your use-case:

from types import SimpleNamespace
from unittest.mock import call, patch

from my_lib import my_func


@patch('my_lib.say_name')
@patch('my_lib.MyClass')
def test_my_func(mock_my_class, mock_say_name):

    class FakeObj:
        pass

    obj1 = FakeObj()
    obj1.name = 'foo'
    obj2 = FakeObj()
    obj2.name = 'bar'
    obj3 = FakeObj()
    obj3.name = 'baz'

    mock_my_class.side_effect = [obj1, obj2, obj3]
    my_func()
    assert mock_my_class.call_args_list == [call('foo'), call('bar'), call('baz')]
    assert mock_say_name.call_args_list == [call('foo'), call('bar'), call('baz')]