Setting up single-player tests before adding spinner

I did that here: https://jsfiddle.net/6vwxnr1e/1/

TypeError: expect(…).toBeSame is not a function

  describe("addPlayer", function() {
    it("is called with the video element", function() {
      const player = {};
      const video = document.createElement("video");

      //then
      expect(player.m).toBeSame("video");
    });
  });
});