MindMap: Fix findNodeDifferences bug

This bug occurred when styled was used.
findNodeDifferences could no longer find a usable key.

src/apps/MindMap/MainView/MainView.jsx

@@ -1,4 +1,5 @@
 import React, { useContext, useEffect, useRef, useState } from 'react'
+import styled from 'styled-components'
 import { ProjectContext } from '../Contexts/ProjectContext'
 
 export function MainView({ theProjectContext = ProjectContext }) {
@@ -61,15 +62,15 @@ function Node({ node: { editing, id, text }, theProjectContext }) {
 
   if (!editing)
     return (
-      <button
+      <Button
         onKeyUp={({ key }) => {
           key === 'Enter' && initiateEditNode(id)
           key === 'c' && createChildNode(id)
           key === 'f' && foldNode(id)
         }}
       >
         {text}
-      </button>
+      </Button>
     )
   else
     return (
@@ -85,3 +86,5 @@ function Node({ node: { editing, id, text }, theProjectContext }) {
       />
     )
 }
+
+const Button = styled.button``

src/apps/MindMap/MindMapTestUtilities.js

@@ -95,7 +95,13 @@ export async function findNodeDifferences(callback) {
   function getKey(Element) {
     const objectKeys = Object.keys(Element)
     const fiberSomething = Element[objectKeys[0]]
-    return fiberSomething?.return?.key
+    return getMeaningfulKey(fiberSomething)
+
+    function getMeaningfulKey(obj) {
+      if (obj?.key) return obj.key
+      if (obj.return) return getMeaningfulKey(obj.return)
+      return null
+    }
   }
 }