text: const { Adder } = require("./adder");
  describe("events based module", () => {
    describe("add", () => {
      it("generates addition event when called", (done) => {
        const adder = new Adder();
        adder.on("added", (result) => {
          expect(result).toBe(3);
          done();
        });
        adder.add(1, 2);
      });
    });
  });
  