fix: properly convert plain text in brackets that is not a link

 closes #1131

Author: paviad

packages/message-parser/src/grammar.pegjs

@@ -31,6 +31,7 @@
     task,
     tasks,
     unorderedList,
+    flatten,
   } = require('./utils');
 }}
 
@@ -227,10 +228,12 @@ InlineItem = Whitespace
  *
  */
 References
-  = "[" title:LinkTitle* "](" href:LinkRef ")" { return title.length ? link(href, reducePlainTexts(title)) : link(href); }
+  = "[" title:LinkTitle* "](" href:LinkRef ")" { return title.length ? link(href, reducePlainTexts(flatten(title))) : link(href); }
   / "<" href:LinkRef "|" title:LinkTitle2 ">" { return link(href, [plain(title)]); }
 
-LinkTitle = (Whitespace / Emphasis) / anyTitle:$(!("](" .) .) { return plain(anyTitle) }
+LinkTitle = (Whitespace / Emphasis) / balanced / anyTitle:$[^\[\]] { return plain(anyTitle) }
+
+balanced = "[" t:LinkTitle* "]" { return reducePlainTexts([plain("["), ...(t || []), plain("]")]) }
 
 LinkTitle2 = $([\x20-\x3B\x3D\x3F-\x60\x61-\x7B\x7D-\xFF] / NonASCII)+
 

packages/message-parser/src/utils.ts

@@ -194,6 +194,12 @@ const joinEmoji = (
   return current;
 };
 
+export const flatten = (values: Paragraph['value']): Paragraph['value'] =>
+  values.reduce(
+    (acc, v) => [...acc, ...(Array.isArray(v) ? v : [v])],
+    [] as Paragraph['value']
+  );
+
 export const reducePlainTexts = (
   values: Paragraph['value']
 ): Paragraph['value'] =>

packages/message-parser/tests/link.test.ts

@@ -560,6 +560,27 @@ Text after line break`,
       ]),
     ],
   ],
+  [
+    '[Jira [Task _emph_ foo] parentheses not working](rocket.chat)',
+    [
+      paragraph([
+        link('rocket.chat', [
+          plain('Jira [Task '),
+          italic([plain('emph')]),
+          plain(' foo] parentheses not working'),
+        ]),
+      ]),
+    ],
+  ],
+  [
+    '[Title 1] bla bla [Title 2](https://foo.com/title2)',
+    [
+      paragraph([
+        plain('[Title 1] bla bla '),
+        link('https://foo.com/title2', [plain('Title 2')]),
+      ]),
+    ],
+  ],
 ])('parses %p', (input, output) => {
   expect(parse(input)).toMatchObject(output);
 });