const expect = require("expect"); const {getImages} = require("./_30s.js"); const jsdom = require("jsdom"); const { JSDOM } = jsdom; const TEST_HTML = new JSDOM("

Hello world

").window.document; test("getImages is a Function", () => { expect(getImages).toBeInstanceOf(Function); }); test("getImages returns an Array", () => { expect(getImages(TEST_HTML)).toBeInstanceOf(Array); }); test("getImages removes duplicates from images Array", () => { expect(getImages(TEST_HTML, false).length).toBeLessThanOrEqual(getImages(TEST_HTML, true).length); expect(getImages(TEST_HTML, true)).toEqual(expect.arrayContaining(getImages(TEST_HTML, false))); });