Bits of .NET

The Test Generation Prompt

Generate comprehensive unit tests for this code:

[Paste your function/class]

Requirements:
- Use [Testing Framework: Jest/xUnit/pytest/etc]
- Test happy path
- Test edge cases (null, empty, invalid input)
- Test error conditions
- Mock external dependencies
- Aim for 90%+ code coverage
- Include descriptive test names
- Add comments explaining what each test validates

Generate at least 10 test cases.

Example Output

// Original function
function calculateDiscount(price, userType) {
  if (userType === 'premium') return price * 0.8;
  if (userType === 'regular') return price * 0.9;
  return price;
}

// AI-generated tests
describe('calculateDiscount', () => {
  test('applies 20% discount for premium users', () => {
    expect(calculateDiscount(100, 'premium')).toBe(80);
  });

  test('applies 10% discount for regular users', () => {
    expect(calculateDiscount(100, 'regular')).toBe(90);
  });

  test('returns original price for guest users', () => {
    expect(calculateDiscount(100, 'guest')).toBe(100);
  });

  test('handles null userType', () => {
    expect(calculateDiscount(100, null)).toBe(100);
  });

  test('handles undefined userType', () => {
    expect(calculateDiscount(100, undefined)).toBe(100);
  });

  test('handles zero price', () => {
    expect(calculateDiscount(0, 'premium')).toBe(0);
  });

  test('handles negative price', () => {
    expect(calculateDiscount(-100, 'premium')).toBe(-80);
  });
});

Generate integration tests for this API endpoint:

[Paste controller code]

Test:
- Authentication (valid/invalid tokens)
- Authorization (different user roles)
- Request validation (missing fields, invalid formats)
- Database interactions (successful CRUD, conflicts)
- Error responses (500, 404, 400, 401, 403)
- Response format validation

Use supertest for HTTP testing.

“Generated 47 test cases for complex payment processing function. AI caught edge cases I never thought of. Test coverage: 23% → 94% in 5 minutes.”