function validate(x: number): Promise<number> {
  return x > 0 ? Promise.resolve(x) : Promise.reject(new Error("inválido"));
}
function transform(x: number): Promise<number> {
  return Promise.resolve(x * 10);
}

// Encadena validate → transform y captura errores con .catch() retornando -1
function safeProcess(x: number): Promise<number> {
  // Tu código aquí
  return validate(x)
        .then(transform)
        .catch( error => {
    
                if(error instanceof Error) {
                  return -1;
    }
  })
  
  // return Promise.resolve(-1);
}

export { safeProcess };