Enhancing Test Stability With Test Doubles for Flaky Test Management

Flaky tests, which unpredictably pass or fail under the same configuration, pose a significant challenge in software development by reducing confidence and wasting resources. Addressing these issues involves using test doubles—such as stubs, mocks, fakes, spies, and dummies—which act as controlled replacements for unpredictable components like external services, thereby increasing test stability and reliability. Each type of test double serves a unique function: dummies act as placeholders, spies track method calls, fakes provide simplified working implementations, mocks verify interactions, and stubs offer predefined responses. By isolating tests from external dependencies, simulating controlled behavior, and simplifying complex setups, test doubles help mitigate common causes of flakiness, such as concurrency issues and time-based dependencies. However, they should be used judiciously alongside other strategies like root cause analysis and code refactoring to ensure comprehensive test reliability without masking underlying issues.