To fix the issue you can do After writing this up, I found the answer, but I feel like this is worth sharing because I was very confused about it. Instead of using app.find(Child) (component constructor), use app.find('Child') (component display name). This will find the actual component and not the hoc-wrapped component.
will help you Enzyme's shallow method just renders the children declared in render method (AppBar, Toolbar, and so on), and the output shows that they are wrapped by the same withStyles HOC. Exporting the testable version of your root component allows you to actually test its real output (div), but won't prevent its children component from being wrapped by withStyles HOC.
Stop React Higher Order Component from mounting before wrapped component?