How to test a function that uses the window.screen.width in jest

Question

I'm trying to test this function in jest, But I cannot override, resize the screen or create a virtual dom.

I'm running this testing on node. ps: I tried to use jsdom but I failed.

functions.js

export const getScreenWidth = () => {
  const screenWidth = window.screen.width;
  if (screenWidth <= 425) return "mobile";
  if (screenWidth <= 768) return "tablet";
  if (screenWidth <= 1024) return "laptopSm";
  if (screenWidth <= 1440) return "laptopLg";
  if (screenWidth <= 2560) return "HD";
  return screenWidth;
};

Answer 1

I tried to make this mock and it worked but I don't really know if this is the right way to do so.

const mockScreen = (size) => {
      global.window = {};
      global.window.screen = {};
      global.window.screen.width = size;
    };

so the final test will be

describe("getScreenWidth()", () => {
  it.only("returns a string representing the width of the screen", () => {
    const mockScreen = (size) => {
      global.window = {};
      global.window.screen = {};
      global.window.screen.width = size;
    };
    mockScreen(425);
    expect(jsf.getScreenWidth()).toBe("mobile");
    mockScreen(2560);
    expect(jsf.getScreenWidth()).toBe("HD");
  });
});