testing-standards

Testing Standards

Coverage Requirements

• Minimum coverage: {{CONFIG.testing.coverageMinimum}}%
• Test command: {{CONFIG.testing.testCommand}}
• Coverage command: {{CONFIG.testing.coverageCommand}}

Test Pyramid

Level	Proportion	Speed	What to Test
Unit	70%	Fast (<100ms)	Functions, classes, utilities
Integration	20%	Medium (<5s)	API endpoints, DB queries, service interactions
E2E	10%	Slow (<30s)	Critical user flows only

Unit Test Rules

• Test one thing per test case
• Use descriptive test names: should {expected behavior} when {condition}
• Follow Arrange-Act-Assert (AAA) pattern
• Mock all external dependencies
• No real network calls, database queries, or file I/O
• Test edge cases: null, undefined, empty, boundary values
• Test error cases as thoroughly as success cases

describe('OrderService', () => {
  describe('calculateTotal', () => {
    it('should return sum of item prices when items exist', () => {
      // Arrange
      const items = [{ price: 10 }, { price: 20 }, { price: 30 }];

      // Act
      const result = calculateTotal(items);

      // Assert
      expect(result).toBe(60);
    });

    it('should return 0 when items array is empty', () => {
      expect(calculateTotal([])).toBe(0);
    });

    it('should throw when items is null', () => {
      expect(() => calculateTotal(null)).toThrow('Items required');
    });
  });
});

Mock Rules

• Use centralized mock infrastructure in tests/mocks/
• Mock at the boundary — don't mock internal implementation
• Keep mocks simple and maintainable
• Reset mocks between tests
• Never use real credentials in test fixtures

Integration Test Rules

• Use test databases (not production)
• Clean up test data after each test (or use transactions)
• Test actual API contracts (request/response shapes)
• Test error responses and status codes
• Use factories/fixtures for test data creation