Using enum as interface key in typescript

To define an interface, the member names must be supplied not computed.

export interface colorsInterface {
    red: boolean;
    blue: boolean;
    green: boolean;
}

If you are worried about keeping the enum and the interface in sync you could use the following:

export interface colorsInterface {
    [color: number]: boolean;
}

var example: colorsInterface = {};
example[colorsEnum.red] = true;
example[colorsEnum.blue] = false;
example[colorsEnum.green] = true;

TypeScript is perfectly happy for you to pass the enum as the index and a rename-refactor would then keep everything together if you decided to rename red, for example.

OK, the key idea is to convert the Enum to the correct Type and to extends the Interface with it: You can check it out in live code here.

const enum Enum {
    key1 = "value1",
    key2 = "value2",
    key3 = "value3",
}
type EnumKeys = keyof typeof Enum;
type EnumKeyFields = {[key in EnumKeys]:boolean}

interface IEnumExtended extends EnumKeyFields {
    KeyEx1:boolean;
    KeyEx2:string;
}

// Test it
const enumInstance: IEnumExtended = {

};

when you inside the enumInstance you will get autocomplete for the Enum keys and not the values.

You can try with type:

export enum colorsEnum{
    red, blue, green
}

export type colorsInterface = {
    [key in colorsEnum]: boolean;
};

let example: colorsInterface = {
    [colorsEnum.red]: true,
    [colorsEnum.blue]: false,
    [colorsEnum.green]: true
};

Or if you do not want to use all keys: add a ?

export type colorsInterface = {
    [key in colorsEnum]?: boolean;
};

let example: colorsInterface = {
    [colorsEnum.red]: true,
    [colorsEnum.blue]: false
};