testing-tdd-workflow

name	testing-tdd-workflow
description	Apply when implementing new features, fixing bugs, or refactoring code. TDD ensures tests drive design and all code is covered.
version	1.0.0
tokens	~600
confidence	high
sources	["https://martinfowler.com/bliki/TestDrivenDevelopment.html","https://blog.cleancoder.com/uncle-bob/2014/12/17/TheCyclesOfTDD.html"]
last_validated	"2025-01-10T00:00:00.000Z"
next_review	"2025-01-24T00:00:00.000Z"
tags	["testing","tdd","workflow","methodology"]

When to Use

Apply when implementing new features, fixing bugs, or refactoring code. TDD ensures tests drive design and all code is covered.

Patterns

Pattern 1: Red-Green-Refactor Cycle

RED:     Write failing test (test what, not how)
GREEN:   Write minimal code to pass
REFACTOR: Improve code, keep tests green
REPEAT:  Next behavior

Source: https://martinfowler.com/bliki/TestDrivenDevelopment.html

Pattern 2: Test Structure (AAA)

// Source: https://martinfowler.com/bliki/GivenWhenThen.html
it('should calculate total with discount', () => {
  // Arrange (Given)
  const cart = new Cart();
  cart.add({ price: 100, quantity: 2 });

  // Act (When)
  const total = cart.calculateTotal(0.1); // 10% discount

  // Assert (Then)
  expect(total).toBe(180);
});

Pattern 3: One Assertion Per Test

// Source: https://blog.cleancoder.com/uncle-bob/2014/12/17/TheCyclesOfTDD.html
// GOOD: Single behavior per test
it('should add item to cart', () => {
  cart.add(item);
  expect(cart.items).toContain(item);
});

it('should update cart count', () => {
  cart.add(item);
  (cart.).();
});


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