Fixes some characters being changed incorrectly in suggestions

This fixes some forward slashes being changed incorrectly in
suggestions.

app/assets/javascripts/lib/utils/text_markdown.js

@@ -233,7 +233,7 @@ export function insertMarkdownText({
     }
   } else if (tag.indexOf(textPlaceholder) > -1) {
     textToInsert = tag.replace(textPlaceholder, () =>
-      selected.replace(/\\n/g, '\n').replace(/\/(n|t|r)/g, '\\$1'),
+      selected.replace(/\\n/g, '\n').replace('%br', '\\n'),
     );
   } else {
     textToInsert = String(startChar) + tag + selected + (wrap ? tag : '');

app/assets/javascripts/vue_shared/components/markdown/field.vue

@@ -16,11 +16,7 @@ import MarkdownHeader from './header.vue';
 import MarkdownToolbar from './toolbar.vue';
 
 function cleanUpLine(content) {
-  return unescape(
-    stripHtml(content)
-      .replace(/\\(n|t|r)/g, '/$1')
-      .replace(/\n/g, ''),
-  );
+  return unescape(stripHtml(content).replace(/\\n/g, '%br').replace(/\n/g, ''));
 }
 
 export default {

spec/frontend/lib/utils/text_markdown_spec.js

@@ -100,7 +100,7 @@ describe('init markdown', () => {
           text: textArea.value,
           tag: '```suggestion:-0+0\n{text}\n```',
           blockTag: true,
-          selected: '# Does not parse the /n currently.',
+          selected: '# Does not parse the %br currently.',
           wrap: false,
         });
 

spec/frontend/vue_shared/components/markdown/field_spec.js

@@ -250,7 +250,7 @@ describe('Markdown field component', () => {
       createSubject([{ rich_text: 'hello world\\n' }]);
 
       expect(subject.find('[data-testid="markdownHeader"]').props('lineContent')).toBe(
-        'hello world/n',
+        'hello world%br',
       );
     });
   });