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quiz vs the machine

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Test Driven Development Frontend

Write a failing test first, then code until it passes, then refactor.

5 min read · core · beat Gold to climb

The red green refactor loop

Test driven development inverts the usual order. You write a failing test that describes desired behavior, write the minimum code to pass it, then refactor with the test as a safety net.

Why it helps on the frontend

  • Forces you to think about the component contract before markup.
  • Produces a suite that documents intended behavior.
  • Encourages small, testable units instead of tangled components.

Doing it well

  • Start at the behavior level using role and text queries, not implementation.
  • Write the smallest test that fails for the right reason.
  • Refactor only when tests are green so you always know you stayed correct.

Where it fits

TDD shines for logic heavy components like forms and validation. For purely visual tweaks, a screenshot or manual check is often more practical than a unit test.

The discipline is the value, the rhythm keeps each step small and verified.

Key idea

TDD cycles red, green, refactor, driving frontend design from behavior and leaving a safety net behind.

Check yourself

Answer to earn rating on the learn ladder.

1. What is the correct TDD order?

2. Where does frontend TDD shine most?