javascript - TypeScript:使用扩展运算符指定值必须在数组中

Question

我正在尝试定义一种类型，其中 favoriteFruit 属性的值必须是选项数组中的一个项目。选项数组是动态/未知的(无法使用联合类型“|”)。

const options = ["apple", "orange", "kiwi"]; // Dynamic list that can be modified in the future 

type Person =  {
  name: string;
  favoriteFruit: /* --- val in [...options] --- */
};

const personA:Person = {name: "Jack", favoriteFruit: "apple"}; // OK
const personB:Person = {name: "John", favoriteFruit: "orange"}; // OK
const personC:Person = {name: "Jane", favoriteFruit: "banana"}; // ERROR

Answer 1

我发现了这个:How to convert array of strings to typescript types? .

const arr = ["foo", "bar", "loo"] as const

type arrTyp = typeof arr[number]; // "foo" | "bar" | "loo"