flexi-js/src/poly/CustomEvent.js

A responsive and flexible css scheme.

try {
  let evt = new CustomEvent('foo');
  evt.preventDefault();
  if (evt.defaultPrevented !== true) {
    throw new Error('failure');
  }
} catch (err) {
  let CustomEvent = (evt, opt) => {
    let e, prev;
    opt = opt || {
      bubbles: false,
      cancelable: false,
      detail: undefined
    }
    e = document.createEvent('CustomEvent');
    e.initCustomEvent(evt, params.bubbles, params.cancelable, params.detail);
    prev = e.preventDefault;
    e.preventDefault = function() {
      prev.call(this);
      try {
        Object.defineProperty(this, 'defaultPrevented', {
          get: () => true
        });
      } catch (err) {
        this.defaultPrevented = true;
      }
    }
    return e;
  };
}