old_contents: require("./chai.helper");
  var domHelper = require("./dom.helper");
  
  describe("removeClass", function () {
      // set up the DOM and some global variables
      beforeEach(function () {
          domHelper(
              "<div id=\"single\" class=\"red\"></div>" +
              "<div id=\"multiple1\" class=\"red green\"></div>" +
              "<div id=\"multiple2\" class=\"orange green\"></div>"
          );
      });
  
      it("should remove a single class from an element", function () {
          $("#single").removeClass("red");
          ($("#single").attr("class") === null).should.be.true;
      });
  
      it("should leave non-matching classes on an element", function () {
          $("#multiple1").removeClass("red");
          $("#multiple1").attr("class").should.equal("green");
      });
  
      it("should not remove any classes if element has none which match", function () {
          $("#multiple2").removeClass("red");
          $("#multiple2").attr("class").should.equal("orange green");
      });
  
      it("should remove multiple classes from an element", function () {
          $("#multiple1").removeClass("red green");
          ($("#multiple1").attr("class") === null).should.be.true;
      });
  
      it("should remove classes from multiple elements", function () {
          var greenDivs = $(".green");
          greenDivs.removeClass("red green");
          (greenDivs[0].getAttribute("class") === null).should.be.true;
          greenDivs[1].getAttribute("class").should.equal("orange");
      });
  });
  
new_contents: require("./chai.helper");
  var domHelper = require("./dom.helper");
  
  describe("removeClass", function () {
      // set up the DOM and some global variables
      beforeEach(function () {
          domHelper(
              "<div id=\"single\" class=\"red\"></div>" +
              "<div id=\"multiple1\" class=\"red green\"></div>" +
              "<div id=\"multiple2\" class=\"orange green\"></div>"
          );
      });
  
      it("should remove a single class from an element", function () {
          $("#single").removeClass("red");
          $("#single").attr("class").should.be.equal("");
      });
  
      it("should leave non-matching classes on an element", function () {
          $("#multiple1").removeClass("red");
          $("#multiple1").attr("class").should.equal("green");
      });
  
      it("should not remove any classes if element has none which match", function () {
          $("#multiple2").removeClass("red");
          $("#multiple2").attr("class").should.equal("orange green");
      });
  
      it("should remove multiple classes from an element", function () {
          $("#multiple1").removeClass("red green");
          $("#multiple1").attr("class").should.be.equal("");
      });
  
      it("should remove classes from multiple elements", function () {
          var greenDivs = $(".green");
          greenDivs.removeClass("red green");
          greenDivs[0].getAttribute("class").should.be.equal("");
          greenDivs[1].getAttribute("class").should.equal("orange");
      });
  });
  
subject: Repair tests for empty attribute class ("" instead of null)