Merge pull request #3331 from serlo/hide-empty-content-in-exercises

fix(plugin-exercise): hide empty content in static view to avoid unexpected margins

packages/editor/src/plugins/exercise/static.tsx

@@ -1,13 +1,25 @@
 import { StaticRenderer } from '@editor/static-renderer/static-renderer'
 import { EditorExerciseDocument } from '@editor/types/editor-plugins'
+import { isRowsDocument } from '@editor/types/plugin-type-guards'
+
+import { isEmptyTextDocument } from '../text/utils/static-is-empty'
 
 export function ExerciseStaticRenderer({ state }: EditorExerciseDocument) {
   const { content, interactive, solution } = state
   if (!content) return null
 
+  const isEmptyContent =
+    isRowsDocument(content) &&
+    content.state.length === 1 &&
+    isEmptyTextDocument(content.state[0])
+
   return (
     <>
-      <StaticRenderer document={content} />
+      {isEmptyContent ? (
+        <div className="mt-6"></div>
+      ) : (
+        <StaticRenderer document={content} />
+      )}
       <StaticRenderer document={interactive} />
       <StaticRenderer document={solution} />
     </>