These testing methodologies represent distinct approaches to verifying software quality. The former confirms the core functionality of an application after a new build or update, ensuring the system doesn’t critically fail. For example, if an e-commerce application’s build fails to allow users to add items to their cart, the build would fail a smoke test. The latter focuses on a specific area of the application to ensure a particular feature works as expected after a change or fix. If a developer fixes a bug in the checkout process, a corresponding test would confirm the repair successfully addresses the reported problem and hasn’t introduced any new issues.
These processes are essential for saving time and resources. Smoke testing identifies major problems early in the development cycle, preventing further testing on unstable builds. Sanity testing confirms that bug fixes work, preventing wasted effort on broken features. These approaches are not exhaustive but rather targeted to quickly assess the stability and correctness of the software. Their historical roots lie in hardware testing, where engineers initially used smoke tests to verify that a newly assembled device would not emit smoke upon initial power-up, indicating catastrophic failure.
