ErrorHandler.ts

import {UserInterface} from "./Classes/User"

var isUpdate = false;

export class ErrorHandler {

    public static idExists(id: number, array: any[]): void {
        if (!(array.find(elem => elem.id == id)))
            throw new Error("Element with id " + id + " does not exist");
        isUpdate = true;
    }

    public static userHandler (input: any) {

        if ((typeof input.name !== "string") || (!input.name.length))
            throw new Error("Invalid user name");
        
        if ((typeof input.email !== "string") || (!input.email.length))
            throw new Error("Invalid user email");

        if ((typeof input.id !== "number") || (isNaN(input.id)))
            throw new Error("Invalid id");

        const newUser: UserInterface = {
            userId: input.id,
            userName: input.name,
            userEmail: input.email
        }
    
        isUpdate = false;
        return newUser;
    }
}