TypeScript extend third party library moment.js

问题

I simply want to add a function to the prototype of the Moment interface which will format always the same way whenever used. I tried already what can be found here.

declare module moment {
    export interface Moment {
        myFormat: () => string;
    }
}

And in some other file, the implementation:

Moment.prototype.myFormat = ():string => { return this.format("DD.MM.YYY"); }

However, this is not working. I simply want to be able to call moment(aDate).myFormat() but I don't get it to work.

Already tried using declare module "moment" and some variations of moment.Moment but still the same.

As found in the link there is no declare used. But then I get the error

'declare' modifier required for top level element.

回答1:

This is working

import moment from 'moment';
declare module 'moment' {
   export interface Moment {
     myFormat: () => string;
   }
 }
moment().myFormat(); 

来源：https://stackoverflow.com/questions/48227192/typescript-extend-third-party-library-moment-js