setup.js

import sinon from 'sinon';

const createElement = global.document.createElement;
const FAKECanvasElement = {
    getContext: jest.fn(() => {
        return {
            fillStyle: null,
            fillRect: jest.fn(),
            drawImage: jest.fn(),
            getImageData: jest.fn(),
        };
    }),
};

sinon.stub(global.document, 'createElement')
    .callsFake(createElement)
    .withArgs('canvas')
    .returns(FAKECanvasElement);