typescript extend an interface as not required

Question

I have two interfaces;

interface ISuccessResponse {     Success: boolean;     Message: string; } 

and

interface IAppVersion extends ISuccessResponse {     OSVersionStatus: number;     LatestVersion: string; } 

I would like to extend ISuccessResponse interface as Not Required; I can do it as overwrite it but is there an other option?

interface IAppVersion {     OSVersionStatus: number;     LatestVersion: string;     Success?: boolean;     Message?: string; } 

I don't want to do this.

Answer 1

A bit late, but Typescript 2.1 introduced the Partial<T> type which would allow what you're asking for:

interface ISuccessResponse {     Success: boolean;     Message: string; }  interface IAppVersion extends Partial<ISuccessResponse> {     OSVersionStatus: number;     LatestVersion: string; }  declare const version: IAppVersion; version.Message // Type is string | undefined