How to represent Guid in typescript?

Question

let's say I have this C# class

public class Product {    public Guid Id { get; set; }    public string ProductName { get; set; }    public Decimal Price { get; set; }    public int Level { get; set; } } 

The equivalent typescript would be something like:

export class Product {   id: ???;   productName: string;   price: number;   level: number; } 

How to represent Guid in typescript?

Answer 1

Guids are usually represented as strings in Javascript, so the simplest way to represent the GUID is as a string. Usually when serialization to JSON occurs it is represented as a string, so using a string will ensure compatibility with data from the server.

To make the GUID different from a simple string, you could use branded types:

type GUID = string & { isGuid: true}; function guid(guid: string) : GUID {     return  guid as GUID; // maybe add validation that the parameter is an actual guid ? } export interface Product {     id: GUID;     productName: string;     price: number;     level: number; }  declare let p: Product; p.id = "" // error p.id = guid("guid data"); // ok p.id.split('-') // we have access to string methods 

This article has a bit more of a discussion on branded types. Also the typescript compiler uses branded types for paths which is similar to this use case.

Answer 2

Another alternative is using following NPM package:

guid-typescript which you can find here: https://www.npmjs.com/package/guid-typescript

Then it will be just like this:

import { Guid } from "guid-typescript";  export class Product {     id: Guid;     productName: string;     price: number;     level: number; }