public async Task <IActionResult> Desconto([FromServices] IVendaService service, [FromBody] DescontoRequest req)
{
var tsc = new TaskCompletionSource <IActionResult>();
try
{
service.DarDesconto(req.VendaId, req.Valor);
tsc.SetResult(RetornoHelper.CreateResponse("OK", 200));
}
catch (Exception e)
{
tsc.SetResult(RetornoHelper.CreateResponse(e.Message, 500));
}
return(await tsc.Task);
}