Function isMounted

code/composition/public/app.js:5286–5302

(component)

}

function isMounted(component) {
  {
    var owner = ReactCurrentOwner.current;
    if (owner !== null && owner.tag === ClassComponent) {
      var ownerFiber = owner;
      var instance = ownerFiber.stateNode;
      warning(instance._warnedAboutRefsInRender, '%s is accessing isMounted inside its render() function. ' + 'render() should be a pure function of props and state. It should ' + 'never access something that requires stale data from the previous ' + 'render, such as refs. Move this logic to componentDidMount and ' + 'componentDidUpdate instead.', getComponentName(ownerFiber) || 'A component');
      instance._warnedAboutRefsInRender = true;
    }
  }

  var fiber = get(component);
  if (!fiber) {
    return false;
  }
  return isFiberMountedImpl(fiber) === MOUNTED;
}

function assertIsMounted(fiber) {
  !(isFiberMountedImpl(fiber) === MOUNTED) ? invariant(false, 'Unable to find node on an unmounted component.') : void 0;