Make Immutable.List useful for Array consume functions without immediate cast to Array

asArray.js

function asArray(target) {
  if (!Immutable.List.isList(target)) {
    throw new TypeError("target is not Immutable.List");
  }

  return new Proxy(new Array(target.size), {
    get(__, key, receiver) {
      if (typeof key !== "symbol") {
        const index = parseInt(key, 10);

        if (Number.isFinite(index) && index >= 0) {
          return target.get(key);
        }

        switch (key) {
          case "fill":
          case "pop":
          case "push":
          case "shift":
          case "sort":
          case "splice":
          case "unshift":
            throw new Error(`Cannot mutate Immutable.List with operation "${key}"`);

          case "length":
            return target.size;

          case "constructor":
            return Array;

          case "concat":
          case "filter":
          case "map":
          case "prototype":
          case "slice":
          case "toString":
            return target.toArray()[key];
        }
      }

      return Reflect.get(target, key, receiver);
    },

    set() {
      throw new Error("Cannot mutate Immutable.List by assignment");
    },

    deleteProperty() {
      throw new Error("Cannot delete properties from Immutable.List");
    },
  });
}