When switching folders, items in SideNav is rendered inefficiently because of path checking occurs in each list item. <img width="501" alt="screen shot 2018-12-21 at 12 38 43" src="https://user-images.githubusercontent.com/5865853/50323540-75cbed00-051d-11e9-9500-c98664a459da.png"> It should be done when mapping list items. So, list items can know it doesn't have to be re-rendered.
When switching folders, items in SideNav is rendered inefficiently because of path checking occurs in each list item.
It should be done when mapping list items. So, list items can know it doesn't have to be re-rendered.