Is it possible to restrict an interface field names according some enum?

Question

Is it possible to restrict an interface field names according some enum (without pointing each value of enum as name)? For example:

enum childSumNames {
    child_incoming_costs = "isv_child_incoming_costs",
    child_est_revenue = "isv_child_est_revenue",
    child_margin = "isv_child_margin",
}

/** Only field names from childSumNames enum are allowed */
interface IChildSumFieldMapper {
    [key in childSumNames]: string // something like this (but it is incorrect syntax)...

    /* instead of this:
     * [childSumNames.child_incoming_costs]: string,
     * [childSumNames.child_est_revenue]: string,
     * [childSumNames.child_margin]: string, */
}

// The example of IChildSumFieldMapper instance
const item: IChildSumFieldMapper = {
    [childSumNames.child_incoming_costs]: "isv_incomingcost",
    [childSumNames.child_est_revenue]: "isv_estimatedrevenue",
    [childSumNames.child_margin]: "isv_margin",
}

Possible duplicate of [How to use enum as index key type in typescript?](https://stackoverflow.com/questions/52700659/how-to-use-enum-as-index-key-type-in-typescript) — Harun Yilmaz, Sep 17 '19 at 07:29
@HarunYilmaz thank you. I updated my code but it is invalid still. I added the screen also. — Andrey Bushman, Sep 17 '19 at 07:35

score 0 · Accepted Answer · answered Sep 17 '19 at 08:35

I do not think that this is possible using interfaces.
You can achieve the same result using types.

enum ChildSumNames {
    child_incoming_costs = 'isv_child_incoming_costs',
    child_est_revenue = 'isv_child_est_revenue',
    child_margin = 'isv_child_margin'
}

type ChildSumFieldMapper = {
    [K in keyof typeof ChildSumNames]: string;
};

const map: Partial<ChildSumFieldMapper> = {
    child_est_revenue: 'a',
    child_incoming_costs: 'b',
    child_margin: 'c'
};

Is it possible to restrict an interface field names according some enum?

1 Answers1