[SOLVED] Error running tests: Cannot read property 'webkitBackingStorePixelRatio' of null

I have a create-react-app project, not ejected, no custom setup.

When I run npm run test I get the following error:

TypeError: Cannot read property ‘webkitBackingStorePixelRatio’ of null

The only test running is the one included with create-react-app, that is:

it("renders without crashing", () => {
  const div = document.createElement("div");
  ReactDOM.render(<App />, div);
  ReactDOM.unmountComponentAtNode(div);
});

Test aside, the app renders properly, no warnings or errors in console.

In the error stack in the console I see three distinct blocks, here’s the first two lines for each:

console.error node_modules/jest-environment-jsdom/node_modules/jsdom/lib/jsdom/virtual-console.js:29 Error: Not implemented: HTMLCanvasElement.prototype.getContext (without installing the canvas npm package)

console.error node_modules/jest-environment-jsdom/node_modules/jsdom/lib/jsdom/virtual-console.js:29 Error: Uncaught [TypeError: Cannot read property ‘webkitBackingStorePixelRatio’ of null]

console.error node_modules/jest-environment-jsdom/node_modules/jsdom/lib/jsdom/virtual-console.js:29 Error: Uncaught [TypeError: Cannot read property ‘current’ of undefined]

The error seems related to jsdom limitations, so I also tried to install canvas and canvas-prebuilt as dev-dependencies with no luck.

Any idea on how to solve this?

[lavrton]

import React from 'react';
import ReactDOM from 'react-dom';
import App from './App';
import Konva from 'konva';

Konva.isBrowser = false;

it('renders without crashing', () => {
  const div = document.createElement('div');
  ReactDOM.render(<App />, div);
  ReactDOM.unmountComponentAtNode(div);
});

[lavrton]

Try to do this before all tests Konva.isBrowser = false;. The simple test works ok for me.