Extracted from https://github.com/facebook/react/issues/12643.

We're currently diff a host node in the complete phase even if it has bailed out in the begin phase. By itself, this just means we're doing a little bit more work than necessary. But it also has some observable effects. In particular, https://github.com/facebook/react/issues/13424 (which by itself would be very rare and probably not worth fixing) is made worse because we end up committing update to inputs from another component.

I have a fix for this in https://github.com/facebook/react/pull/13423. Filing this for posterity.
parentInstance: Container | Instance,
    child: Instance | TextInstance,
  ): void {
    const index = parentInstance.children.indexOf(child);
    if (index === -1) {
      throw new Error('This child does not exist.');
    }
    parentInstance.children.splice(index, 1);
  }
  function removeChildFromContainer(
    parentInstance: Container,
    child: Instance | TextInstance,
  ): void {
    if (typeof parentInstance.rootID !== 'string') {
      
      
      throw new Error(
        'removeChildFromContainer() first argument is not a container.',
      );
    }
    removeChildFromContainerOrInstance(parentInstance, child);
  }
  function removeChild(
    parentInstance: Instance,
    child: Instance | TextInstance,
  ): void {
    if (typeof (parentInstance: any).rootID === 'string') {
      
      
      throw new Error('removeChild() first argument is not an instance.');