2 posts tagged with "tests"

Mocking entire classes and objects is a crucial skill for unit testing complex code. When a function instantiates a class or calls methods on a passed-in object, you need a way to control that object's behavior without executing its real logic. This article will cover advanced mocking techniques, focusing on how to mock classes and instance methods using both the standard unittest.mock library and the more convenient pytest-mock plugin. We will also clarify key distinctions between different types of test doubles.

External dependencies are a major source of pain in unit testing. They can be slow, unreliable, and difficult to control. Mocking these external services is the single most common and valuable use of the unittest.mock library [1]. This article will provide practical, hands-on examples for mocking three of the most frequent external dependencies: HTTP requests, database connections, and file system operations.