Add back teardown function

Author: khanniie

client/modules/IDE/components/Editor/codemirror.js

@@ -94,6 +94,14 @@ export default function useCodeMirror({
     });
   }
 
+  //  When the component unmounts, we want to clean up the CodeMirror instance.
+  function teardownCodeMirror() {
+    if (cmView.current) {
+      cmView.current.destroy();
+      cmView.current = null;
+    }
+  }
+
   // When settings change, we pass those changes into CodeMirror.
   // TODO: There should be a useEffect hook for when the theme changes.
   useEffect(() => {
@@ -201,6 +209,7 @@ export default function useCodeMirror({
 
   return {
     setupCodeMirrorOnContainerMounted,
+    teardownCodeMirror,
     getContent,
     tidyCode
     // showFind,

client/modules/IDE/components/Editor/index.jsx

@@ -84,6 +84,7 @@ function Editor({
   // a reference to the actual CM instance.
   const {
     setupCodeMirrorOnContainerMounted,
+    teardownCodeMirror,
     // cmInstance,
     getContent,
     tidyCode
@@ -130,6 +131,7 @@ function Editor({
 
     return () => {
       provideController(null);
+      teardownCodeMirror();
     };
   }, []);