I spent three hours yesterday trying to integrate a payment gateway using the official docs. The instructions claimed I needed version 2.0, but the SDK threw errors until I downgraded to 1.8. Documentation rots the moment you publish it.
Tests do not have that luxury. If the code breaks, the test suite turns red. It is the only record of how the system expects to behave in the real world.
Stop writing long README files that no one updates. Instead, write tests that explain your logic through inputs and outputs. A well-named test file like verify_user_subscription_flow.spec.js tells a developer more than a wiki page ever could.
Write the test you wish the previous person had written. Define the edge cases. Use descriptive names for your functions so the test output reads like a manual. If a new dev can understand your business logic by reading the test titles, you win.
Delete the outdated design doc folder in your repo today. Replace it with a test that validates your most critical user path. If the test passes, your docs are accurate.
Victor Solano