从键的联合创建对象类型

Question

我了解keyof运算符以及如何创建由该对象的键组成的联合类型，如下所示：

interface Foo {
  a: string;
  b: string;
}

type Goo = keyof Foo; // "a" | "b"

我想做完全相反的事情，并从键的联合创建一个新的对象类型。

const MakeTuple = <T extends string[]>(...args: T) => args;
const Types = MakeTuple("A", "B", "C");
type TypeVariant = typeof Types[number];

type VariantObject = {
  // This gives error consider using a mapped object but I'm not sure how to do that
  [type: TypeVariant]: [boolean, boolean, boolean, string[]];
}

所以我想要的是采用键的联合并生成一个类型，其中包含 type 的每个键的值[boolean, boolean, boolean, string[]]。

Answer 1

您可以只使用预定义的Record映射类型

const MakeTuple = <T extends string[]>(...args: T) => args;
const Types = MakeTuple("A", "B", "C");
type TypeVariant = typeof Types[number];

type VariantObject = Record< TypeVariant, [boolean, boolean, boolean, string[]] >