Last Updated on October 25, 2023 by Deya Eldeen
Test doubles name is inspired by “stunt doubles” from movies industry.
Testing is an essential part of software development, allowing us to ensure the correctness and reliability of our code.
However, when it comes to writing tests, one concept that often perplexes developers is the use of test doubles, test doubles are objects that replace dependencies in our code during testing, enabling us to isolate and verify specific behaviors.
In general, there are various types of test doubles, such as dummies, fakes, stubs, spies, and mocks, understanding when and how to use each type can greatly enhance the effectiveness of our tests and improve the overall quality of our code.
In this blog post series, we will delve into the world of test doubles in Swift, exploring their purpose, distinctions, and practical examples, by the end, you’ll have a solid understanding of how to leverage test doubles to write comprehensive and reliable tests.
A test double is an object that stands in for a real dependency during testing, these dependencies, such as external services, databases, or complex components, can introduce complexity and make testing challenging, test doubles help us isolate the code under test and focus on specific behaviors, making our tests more reliable and efficient.
Test doubles are designed to mimic the behavior of real objects, but they provide simplified or controlled implementations, by replacing real dependencies with test doubles, we can create predictable and controlled environments for testing, without relying on external systems or complex setups.