Tests as Maintainable Documentation | Generated by AI
Question: What is one good benefit of unit tests, integration tests, or automated tests in general?
Answer:
One significant advantage of unit tests, integration tests, and automated tests is that they explicitly document and share testing knowledge in a maintainable, reusable form.
By writing tests as code:
- The test cases, expected behaviors, edge cases, and setup procedures are captured explicitly in the codebase rather than remaining tacit knowledge in individual testers’ or developers’ minds.
- New team members can quickly understand how to test the system by reading and running the existing tests, lowering the onboarding barrier.
- The testing approach becomes a shared, version-controlled asset that evolves with the product. As features change, tests are updated accordingly, ensuring the testing knowledge stays current.
- It reduces the “bus factor” risk: if the person who knows “how things are really tested” leaves the team, the knowledge isn’t lost because it’s encoded in the tests.
- Automated execution ensures consistency—everyone runs the same tests the same way, eliminating variations that often occur in manual testing due to human interpretation.
In contrast, pure manual testing often keeps critical testing details (scripts, sequences, assertions, and corner cases) as undocumented mental models. This leads to inconsistency, knowledge silos, and loss of expertise when people move on.
Automated tests turn testing into a durable, collaborative engineering practice rather than an individual craft.
References:
- Martin Fowler on the value of tests as documentation
- Google Testing Blog: The Value of Automated Testing