Dataclass like utility.

models.js

function makeModel (fields) {
  return class BaseModel {
    constructor(options) {
      options = options || {}

      var v;
      for (var [key, value] of Object.entries(fields)) {
        if (options.hasOwnProperty(key)) {
          v = options[key]
        } else {
          v = value
        }
        if (typeof(v) === "function") {
          this[key] = v()
        } else {
          this[key] = v
        }
      }
    }
  }
}



export class User extends makeModel({
  id: null,
  username: null,
  iconUrl: ''
}) {}