[Security Solution][Investigations] Fixes rendering issue of last element of a task list when empty (#122242) (#122266)

* fix: fixes the issue where the last element of a task list would not render properly

* test: update test

Co-authored-by: Jan Monschke <jan.monschke@elastic.co>

x-pack/plugins/security_solution/public/timelines/components/notes/helpers.test.tsx

@@ -0,0 +1,22 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { createNote } from './helpers';
+
+describe('createNote', () => {
+  it(`does not trim the note's text content`, () => {
+    // A note with two empty todo items.
+    // Notice the required trailing whitespace which is required otherwise
+    // markdown renderers will not render the list correctly
+    const note = '- [ ] \n\n- [ ] ';
+    expect(createNote({ newNote: note })).toEqual(
+      expect.objectContaining({
+        note,
+      })
+    );
+  });
+});

x-pack/plugins/security_solution/public/timelines/components/notes/helpers.tsx

@@ -79,7 +79,7 @@ export const createNote = ({ newNote }: { newNote: string }): Note => ({
   created: moment.utc().toDate(),
   id: uuid.v4(),
   lastEdit: null,
-  note: newNote.trim(),
+  note: newNote,
   saveObjectId: null,
   user: 'elastic', // TODO: get the logged-in Kibana user
   version: null,