describe('Either vs Validation comparison', () => {
  it('Either fails fast', () => {
    const result = validateUserEither('', -5)
    expect(result._tag).toBe('Left')
    if (result._tag === 'Left') {
      // Only gets first error
      expect(typeof result.left).toBe('string')
    }
  })

  it('Validation accumulates errors', () => {
    const result = validateUserValidation('', -5)
    expect(result._tag).toBe('Left')
    if (result._tag === 'Left') {
      // Gets both errors
      expect(result.left.length).toBe(2)
    }
  })

  it('Both succeed with valid input', () => {
    const result1 = validateUserEither('Alice', 25)
    const result2 = validateUserValidation('Alice', 25)
    expect(result1._tag).toBe('Right')
    expect(result2._tag).toBe('Right')
  })
})