Test-Driven Development
TDD
ELI5 — The Vibe Check
Test-Driven Development is a discipline where you write your tests before your actual code. You describe what success looks like first, then make it happen. It forces you to think about your code's behavior before you write a single line of logic.
Real Talk
TDD is a development process that relies on repeating a short cycle: write a test that defines a desired improvement or new function, run the test (it fails — red), write the minimum code to pass the test (green), then refactor the code while keeping tests passing.
When You'll Hear This
"Does your team do test-driven development?" / "Test-driven development makes refactoring way less scary."
Related Terms
Assertion
An assertion is your test saying 'I DEMAND this is true!'. It's you checking that the result is what you expected.
BDD (BDD)
BDD is like writing your tests in plain English so your non-coder boss can also understand them.
Red-Green-Refactor
Red-Green-Refactor is the TDD dance: Red means write a test that FAILS (it's red in the output).
TDD (TDD)
TDD means you write the test BEFORE you write the code.
Unit Test
A unit test is like checking that one single LEGO brick isn't broken before you use it in your big castle.