How to declare and import typescript interfaces in a separate file

Question

I want to define several interfaces in their own file in my typescript-based project, from which I\'ll implement classes for production as well as mocks for testing. However

Answer 1

You need to export the interface from the file in which is defined and import it wherever you want to use it.

in IfcSampleInterface.ts:

export interface IfcSampleInterface {
   key: string;
   value: string;
}

In SampleInterface.ts

import { IfcSampleInterface } from './IfcSampleInterface';
let sampleVar: IfcSampleInterface;