text: /*globals chai , describe , it , SvgBarChart, AnalyserNode , SVGSVGElement , AudioVisualizer , SvgBar , SVGRectElement , window  , document*/
  var expect = chai.expect;
  var assert = chai.assert ;
  
  describe("SvgBarChart", function() {
   it("AudioVisualizer should be  constructor function instance", function() {
        var audioVisualizer = new AudioVisualizer() ; 
        assert.ok( audioVisualizer instanceof AudioVisualizer  , "AudioVisualizer is a constructor function" );
   });
   it("should accept audio param", function() {
        var audio = document.getElementById('myAudioSample') ;
        var audioVisualizer = new AudioVisualizer(audio) ; 
        assert.ok( audioVisualizer.audio === audio , "audio element found" );
   });
   it("isAudioPresent function ok ", function() {
        var audio = document.getElementById('myAudioSample') ;
        var audioVisualizer = new AudioVisualizer(audio) ;
        assert.ok( audioVisualizer.isAudioPresent(), "isAudioPresent Function ok" );
   });
   it("create audio element from url ", function() {
        var audioVisualizer = new AudioVisualizer('/base/public/audio/source.mp3') ;
        assert.ok( audioVisualizer.isAudioPresent(), "create audio element from url" );
    });
   it("isAudioPresent function ok setup nodes  ", function() {
         var audioVisualizer = new AudioVisualizer('/base/public/audio/source.mp3') ;
        audioVisualizer.setupNodes() ;
        var analyser = audioVisualizer.analyser ;
        assert.ok( analyser && analyser instanceof AnalyserNode , "setup nodes ok " );
   });
  it("startRendering method should start audio play", function() {
        var audioVisualizer = new AudioVisualizer('/base/public/audio/tokyo.mp3') ;
    audioVisualizer.setupNodes() ;
    assert.ok( true === true , "true is true" );
   });
  });