zone_basic_hooks.js

var zone = Zone.current.fork({
  name: 'hook',
  onScheduleTask(delegate, current, target, task) {
    console.log('schedule ZoneTask', task.type, task.source);
    return delegate.scheduleTask(target, task);
  },
  onInvokeTask(delegate, current, target, task, applyThis, applyArgs) {
    console.log('invoke ZoneTask', task.type, task.source);
    return delegate.invokeTask(target, task, applyThis, applyArgs);
  },
  onHasTask(delegate, current, target, hasTaskState) {
    console.log('hasTask state: ', hasTaskState);
    return delegate.hasTask(target, hasTaskState);
  }
});
zone.run(() => {
  setTimeout(function() {
    console.log('timer callback invoked');
  }, 1000);
});

// schedule ZoneTask macroTask setTimeout
// hasTask state {macroTask: true, microTask: false, eventTask: false}
// invoke ZoneTask macroTask setTimeout
// timer callback invoked
// hasTask state {macroTask: false, microTask: false, eventTask: false}