Test-Driven Development (TDD)

What is it?

TDD means writing the test before writing the code. First, I write a test that says what the code should do. I run it — it fails (because the code doesn't exist yet). Then I write just enough code to make it pass. Then I improve the code while keeping the test green. Red. Green. Refactor.

Why does it matter?

Every feature has a test that proves it works. Not 'we tested it manually last week' but 'the computer verifies it on every change.' If a future change breaks something, you know instantly. Your application becomes more reliable over time, not less.

Benefits

For you

Every feature is verified automatically. Regressions are caught immediately. Your app gets more reliable, not less.

For the build

Red-green-refactor cycle. Instant feedback. Confidence to refactor. Living documentation.