testing-scenarios

name	testing-scenarios
description	Testing scenarios for validation, error handling, and edge cases. Use when writing comprehensive tests covering happy paths, errors, and edge cases.
license	Apache 2.0

Testing Scenarios

When to Use This Skill

• Writing comprehensive tests
• Testing edge cases
• Testing error scenarios

Core Concepts

Testing Validation

describe('Validation', () => {
  it.each([
    ['invalid email', { email: 'invalid', name: 'Test' }],
    ['empty name', { email: '[e-mail]', name: '' }],
    ['short password', { email: '[e-mail]', password: '123' }],
  ])('should reject %s', (_, invalidData) => {
    expect(() => validator.validate(invalidData))
      .toThrow(ValidationError);
  });
});

Testing Error Handling

it('should handle database connection error', async () => {
  mockRepository.create.mockRejectedValue(
    new DatabaseConnectionError('Connection failed')
  );
  
  await expect(service.createUser(userData))
    .rejects
    .toThrow(DatabaseConnectionError);
});

Testing Edge Cases

describe('Edge Cases', () => {
  it('should handle empty array', () => {
    expect(service.calculateTotal([])).toBe(0);
  });
  
  it('should handle null/undefined', () => {
    expect(service.process(null)).toEqual(defaultValue);
  });
  
  it('should handle special characters', () => {
    const input = '<script>alert("xss")</script>';
    expect(service.sanitize(input)).not.toContain('<script>');
  });
});

Async Testing

it('should fetch user data', async () => {
  const result = await service.getUser('123');
  expect(result).toBeDefined();
});

it('should throw error', async () => {
  await expect(service.invalidOperation())
    .rejects
    .toThrow(ValidationError);
});

References

• Testing JavaScript Applications