fabric.js/src/log.js

/**
 * Wrapper around `console.log` (when available)
 * @param {Any} values Values to log
 */
fabric.log = function() { };

/**
 * Wrapper around `console.warn` (when available)
 * @param {Any} Values to log as a warning
 */
fabric.warn = function() { };

if (typeof console !== 'undefined') {
  if (typeof console.log !== 'undefined' && console.log.apply) {
    fabric.log = function() {
      return console.log.apply(console, arguments);
    };
  }
  if (typeof console.warn !== 'undefined' && console.warn.apply) {
    fabric.warn = function() {
      return console.warn.apply(console, arguments);
    };
  }
}