增强TypeScript中声明的名称空间中的接口

Question

I want to augment the IHttpPromise<T> inside the declared angular namespace (from "@types/angular"). So that I'll be able to write $http.then(...).myCustomMethod(...) .

I was able to augment interfaces in the global context easily by just writing:

interface JQuery {
    $custom: string;
}

For interfaces inside namespaces, the same doesn't work obviously. Tried several things like declaring the angular namespace again and putting the augmented interface inside, but that and other numerous variations didn't work.

Note that I'm not using (external) modules.

Answer 1

Found the solution. Even if you're not using modules, you'll have to do the following in a separate declaration file:

import { IHttpPromise } from '@types/angular';

declare module '@types/angular' {
    interface IHttpPromise<T> {
        myCustomMethod(): something;
    }
}

The import statement's content itself is not important. We have to do an import to make TS treat this file as a module for this to work. So this would've also worked:

import * as angular from '@types/angular';

This is documented at the end here .