label_hiding.js

function bind_label_hiding(){
  $("div.feedback_row label").each(function(index, item){
    var field = $("#" + $(item).attr("for"));
    field.bind("focus", function(){
      $(item).hide();
      });
    
    field.bind("blur", function(){
      if (jQuery.trim(field.attr("value")) == "") $(item).show();
      });
    if (jQuery.trim(field.attr("value")) != "") $(item).hide();
  });
}
function attach_feedback_ujs(){
//  bind_label_hiding();
  bind_tab_activation();
}

label_hiding_spec.js

 describe("FeedbackLabelHiding", function(){

    describe("on load ", function(){
      before(function(){
        $("#labeltext1").show();
      });
      describe("with no text entered ", function(){
        it("should not hide the label", function(){
          $("#text1").attr("value", "");
          attach_feedback_ujs();
          expect($("#labeltext1")).to(be_visible);
        });
      });
      
      describe("with text entered ", function(){
        it("should hide the label", function(){
          $("#text1").attr("value", "hi");
          attach_feedback_ujs();
          expect($("#labeltext1")).to_not(be_visible);
        });
      });

      describe("with empty string entered ", function(){
        it("should not hide the label", function(){
          $("#text1").attr("value", "   ");
          attach_feedback_ujs();
          expect($("#labeltext1")).to(be_visible);
        });
      });
      
    });