[WordPress] JavaScript helper function for making Customizer code less redundant. In this example, it's for toggling the visibility of a social icon.

customizer-social-icon-visibility.js

function toggleSocialIconVisibility( $, sId, sControlId ) {
  'use strict';

  // Toggle the visibility based on the string value of element
  wp.customize( sControlId, function( value ) {
    value.bind( function( to ) {

    if ( 0 < $.trim( to ).length ) {
      $( sId ).removeClass( 'hidden' );
    } else {
      $( sId ).addClass( 'hidden' );
    }

    });
  });

}

customizer-social-icons-page-load.js

(function( $ ) {
  'use strict';

  $(function() {

    toggleSocialIconVisibility( $, '#facebook', 'mayer_facebook_url' );
	
  });

})( jQuery );