如何基于枚举结构为 object 创建类型

Question

I have a enum as below.

export enum Hotkey {
    MARK_IN = 'markIn',
    MARK_OUT = 'markOut',
    GO_TO_MARK_IN = 'goToMarkIn',
    GO_TO_MARK_OUT = 'goToMarkOut'
}

Now i want to create a type for a json object that should allow only the keys present in enum but not some random key during development.

type hotkey = keyof typeof Hotkey;

type clone = {[key:hotkey]: string}

const finalObject: clone = {
    MARK_IN : 'markIn'
};

i created the type as above but that is erroring out when i create the type "clone"

Error: An index signature parameter type cannot be a literal type or generic type. Consider using a mapped object type instead.ts(1337)

Answer 1

You can create a type using an enum for the key this way:

export enum Hotkeys {
  MARK_IN = 'markIn',
  MARK_OUT = 'markOut',
  GO_TO_MARK_IN = 'goToMarkIn',
  GO_TO_MARK_OUT = 'goToMarkOut'
};

type IHotkey = `${ Hotkeys }`;

type IClone = {
  [key in IHotkey]?: string
};

If you want to use the enum member as the key you can also do:

const yourObject: IClone = {
  [Hotkeys.MARK_IN] = 'your-value'
}