/index.ts(3,16): error TS2671: Cannot augment module './test' because it resolves to a non-module entity.
/index.ts(7,3): error TS2551: Property 'toFixed' does not exist on type 'string'. Did you mean 'fixed'?


==== /test.js (0 errors) ====
    module.exports = {
      a: "ok"
    };
    
==== /index.ts (2 errors) ====
    import { a } from "./test";
    
    declare module "./test" {
                   ~~~~~~~~
!!! error TS2671: Cannot augment module './test' because it resolves to a non-module entity.
      export const a: number;
    }
    
    a.toFixed();
      ~~~~~~~
!!! error TS2551: Property 'toFixed' does not exist on type 'string'. Did you mean 'fixed'?
!!! related TS2728 lib.es2015.core.d.ts:--:--: 'fixed' is declared here.
    