Jest unit test with GraphicsLayer

[AdamPigg]

I have a custom Experience Builder widget which itself works fine, but im having trouble writing a unit test for it.  The widget creates a GraphicsLayer in the constructor and the import for it looks like

import { GraphicsLayer } from "esri/layers/GraphicsLayer";

When it comes to the unit test, it fails with the error

TypeError: GraphicsLayer_1.GraphicsLaye is not a constructor

If i change the import to 

import GraphicsLayer from "esri/layers/GraphicsLayer";

the error changes to 

TypeError: GraphicsLayer_1.default is not a constructor

What am I missing, i tried adding a mock like

jest.mock("esri/layers/GraphicsLayer");

But that didnt help.

Thanks

[AdamPigg]

So, i can get past that error with the following mock:

jest.mock("esri/layers/GraphicsLayer", () => {

    return {

        __esModule: true,

        default: jest.fn().mockImplementation(() => {

            return {

                init: mockedExp

            };

        })

    };

});

But then i get stuck on a similar error

TypeError: projection_1.default.load is not a function

Which so far ive been unable to mock...is there an easier trick im missing?