missing error handling and headers

[abdhalees]

this function is missing: 1- error handling 2- headers, when you don't specify your headers they will be set by the browser but you don't want to always relay on browsers they aren't always that clever. https://github.com/facg3/MWM-Shop_Project/blob/ed635ae78424fb61b8a6e2ee5c0c38d484307378/src/handler.js#L20

[MahmoudMH]

humm , yub ! on the next project insaallah , it generate some errs