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(function($) {

/* by Elijah Manor with collaboration from Doug Neiner
 * Filter results by html5 data attributes either at 
 * design or at runtime
 *
 * Usages:
 * $( "p" ).filterByData( "mytype" );
 * $( "p" ).filterByData( "mytype, "mydata" );
 */
$.fn.filterByData = function( type, value ) {
    return this.filter( function() {
        var $this = $( this );

        return value != null ?
            $this.data( type ) === value :
            $this.data( type ) != null;
    });
};

})(jQuery);

pavlov.specify.globalApi = true;
pavlov.specify( "filterByData jQuery Plugin", function() {

  var $fixture = $( "#qunit-fixture" );
    
  describe( "Design-time Checks", function() {

    it( "should match an element that has no value", function() {
      var $p = $( "<p data-mytype></p>" ).appendTo( $fixture )
          .filterByData( "mytype" );
      
      assert( $p ).isDefined();        
      assert( $p.length ).isEqualTo( 1 );
    });
    
    it( "should match an element that is an empty string", function() {
      var $p = $( "<p data-mytype=''></p>" ).appendTo( $fixture )
          .filterByData( "mytype" );
      
      assert( $p ).isDefined();        
      assert( $p.length ).isEqualTo( 1 );        
    });

    it( "should match an element that has a non-empty value", function() {
      var $p = $( "<p data-mytype='test'></p>" ).appendTo( $fixture )
          .filterByData( "mytype" );
      
      assert( $p ).isDefined();        
      assert( $p.length ).isEqualTo( 1 );        
    });  
   
    it( "should match an element based on it's value", function() {
      var $p = $( "<p data-mytype='test1'></p>" + 
           "<p data-mytype='test2'></p>" )
          .appendTo( $fixture )
          .filterByData( "mytype", "test1" );
      
      assert( $p ).isDefined();        
      assert( $p.length ).isEqualTo( 1 );        
    });      
      
      
    it( "should support popping off the stack", function() {
      var $p = $( "<p data-mytype='test1'></p>" + 
           "<p data-mytype='test2'></p>" )
          .appendTo( $fixture )
          .filterByData( "mytype", "test1" )
          .end();
              
      assert( $p ).isDefined();
      assert( $p.length ).isEqualTo( 2 );
    });       
      
  });
  
  describe( "Run-time Checks", function() {
  
    it( "should match an element that a data-mytype was added as an empty string", function() {
      var $p = $( "<p></p>" )
          .data( "mytype", "" )
          .appendTo( $fixture )
          .filterByData( "mytype" );

      assert( $p ).isDefined();    
      assert( $p.length ).isEqualTo( 1 );        
    });

    it( "should match an element that a data-mytype was added as a non-empty string", function() {
      var $p = $( "<p></p>" )
          .data( "mytype", "test" )
          .appendTo( $fixture )
          .filterByData( "mytype" );

      assert( $p ).isDefined();    
      assert( $p.length ).isEqualTo( 1 );        
    });  

    it( "should match an element that a data-mytype was added based on it's value", function() {
      var $p = $( "<p></p>" )
          .data( "mytype", "test" )
          .appendTo( $fixture )
          .filterByData( "mytype", "test" );

      assert( $p ).isDefined();    
      assert( $p.length ).isEqualTo( 1 );        
    });  
            
  });
  
});

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