While working on the DevTools profiler, I've noticed that durations are sometimes incorrect. This seems to be vaguely related to high/low priority state updates. Need to track this down more so I'm filing an issue for myself.
<Child duration={duration} id={id} />
            <Child duration={duration} id={id} />
          </React.Fragment>
        );
      }
    }
    ReactNoop.advanceTime(50);
    ReactNoop.renderToRootWithID(<Parent duration={3} id="one" />, 'one');
    
    
    const commitFirstRender = ReactNoop.flushWithoutCommitting(
      ['Child:render:one', 'Child:render:one'],
      'one',
    );
    expect(ReactNoop.getRoot('one').current.actualDuration).toBe(0);
    ReactNoop.advanceTime(100);
    
    ReactNoop.renderToRootWithID(<Parent duration={7} id="two" />, 'two');
    ReactNoop.flushThrough(['Child:render:two']);
    ReactNoop.advanceTime(150);
    
    commitFirstRender(['Parent:componentDidMount:one']);
    expect(ReactNoop.getRoot('one').current.actualDuration).toBe(6);
    expect(ReactNoop.getRoot('two').current.actualDuration).toBe(0);
    ReactNoop.advanceTime(200);
    ReactNoop.flush();
    expect(ReactNoop.getRoot('two').current.actualDuration).toBe(14);
  });
});