import "mocha"; import { expect } from "chai"; import { is } from "../helpers"; describe('Thunk factory "is.directInstanceOf"', () => { it("recognizes direct instances of a class", () => { const Thing = class {}; const Thingy = class extends Thing {}; const thunk = is.directInstanceOf(Thing); expect(thunk(new Thing())).to.be.true; expect(thunk(new Thingy())).to.be.false; }); });