Introduction

Security testing is a crucial aspect of Test-Driven Development. This article explores how to incorporate security testing into your TDD workflow to build more secure applications.

Input Validation Testing


// userValidation.test.js
describe('User Input Validation', () => {
  test('should reject SQL injection attempts', () => {
    const input = "'; DROP TABLE users; --";
    expect(() => validateUserInput(input))
      .toThrow('Invalid input');
  });

  test('should reject XSS attempts', () => {
    const input = 'alert("xss")';
    expect(() => validateUserInput(input))
      .toThrow('Invalid input');
  });

  test('should sanitize HTML input', () => {
    const input = 'Hello World';
    const sanitized = sanitizeInput(input);
    expect(sanitized).toBe('Hello World');
  });
});

Authentication Testing


// auth.test.js
describe('Authentication', () => {
  test('should hash passwords', async () => {
    const password = 'password123';
    const hashed = await hashPassword(password);
    expect(hashed).not.toBe(password);
    expect(hashed).toMatch(/^$2[aby]$d+$/);
  });

  test('should verify correct password', async () => {
    const password = 'password123';
    const hashed = await hashPassword(password);
    const isValid = await verifyPassword(password, hashed);
    expect(isValid).toBe(true);
  });

  test('should reject incorrect password', async () => {
    const password = 'password123';
    const hashed = await hashPassword(password);
    const isValid = await verifyPassword('wrongpassword', hashed);
    expect(isValid).toBe(false);
  });
});

Authorization Testing


// authorization.test.js
describe('Authorization', () => {
  test('should allow admin access', () => {
    const user = { role: 'admin' };
    const resource = { ownerId: 1 };
    expect(canAccess(user, resource)).toBe(true);
  });

  test('should allow owner access', () => {
    const user = { id: 1, role: 'user' };
    const resource = { ownerId: 1 };
    expect(canAccess(user, resource)).toBe(true);
  });

  test('should deny unauthorized access', () => {
    const user = { id: 2, role: 'user' };
    const resource = { ownerId: 1 };
    expect(canAccess(user, resource)).toBe(false);
  });
});

CSRF Protection


// csrf.test.js
describe('CSRF Protection', () => {
  test('should validate CSRF token', () => {
    const token = generateCSRFToken();
    expect(validateCSRFToken(token)).toBe(true);
  });

  test('should reject invalid CSRF token', () => {
    expect(validateCSRFToken('invalid-token')).toBe(false);
  });

  test('should reject expired CSRF token', () => {
    const token = generateCSRFToken();
    // Simulate token expiration
    jest.advanceTimersByTime(24 * 60 * 60 * 1000);
    expect(validateCSRFToken(token)).toBe(false);
  });
});

Best Practices

  • Test all security measures
  • Verify input validation
  • Test authentication flows
  • Check authorization rules
  • Validate security headers

Conclusion

Security testing should be an integral part of your TDD workflow. By following these practices, you can build more secure applications and catch security issues early in the development process.

"Security is not a feature, it's a requirement." - Bruce Schneier