Building Enterprise JavaScript Applications

Tests as specification

Whilst avoiding manual testing is a benefit of TDD, it certainly is not the only one. A developer can still write their unit, integration and E2E tests after implementation of the feature. So what are the benefits of writing tests before implementation?

The answer is that it forces you to think about your requirements and break them down into atomic units. You can then write each test case around a specific requirement. The end result is that the test cases form the specification for your feature. Writing tests first helps you structure your code around the requirements, rather than retrofitting requirements around your code.

This also helps you to abide by the You Aren't Gonna Need It (YAGNI) principle, which prevents ...