Unittest: Enhancing Mock Objects with Names in Unittest

Author

Andres Monge

Published

January 3, 2025

When working with unittest.mock in Python, it can be challenging to set the name attribute directly when creating a mock object. This article will guide you through the process of setting a name attribute for a mock object, highlighting the best practices and workarounds.

Context

Since the name attribute is not directly supported by the Mock constructor, you need to use alternative methods to achieve this. Here are the two main approaches:

Using configure_mock

Code
from unittest.mock import MagicMock

mock = MagicMock()
mock.configure_mock(name='my_name')
print(mock.name)  # Output: 'my_name'
my_name

Setting the name attribute after creation

Code
mock = MagicMock()
mock.name = "foo"
print(mock.name)  # Output: 'foo'
foo

Example: Setting Names for Mocked Objects

When you need to create a list of mocked objects with specific names, you can follow the second approach. Here’s an example:

Code
from unittest.mock import Mock, patch

items = []
for pod_name in [ "10000X", "20000X", "30000X" ]:
    item = Mock(metadata=Mock())
    item.metadata.name = pod_name
    items.append(item)

mocked_pod_list = Mock(items=items)
patch(
    "src.row.steps.libs.query.CoreV1Api.list_namespaced_pod",
    return_value=mocked_pod_list,
)
<unittest.mock._patch at 0x7253c3f83da0>

This approach ensures that each item in the items list has a metadata.name attribute set correctly, which is essential for identifying and debugging the mocked objects in your tests.

References

  • Setting Mock Names: For more information on setting names for your mocks, refer to the official Python documentation on unittest.mock.
  • Workarounds for name Attribute: The workaround for not being able to set the name attribute directly during mock creation is documented in the Python issue tracker.

By following these steps and using the provided workarounds, you can effectively manage and identify your mocked objects in your unit tests, enhancing the clarity and reliability of your test code.