fix(message-parser): parse emojis and inline elements inside headings

Author: Harshit2405-2004

.changeset/fix-heading-emoji-parsing.md

@@ -0,0 +1,5 @@
+---
+"@rocket.chat/message-parser": patch
+---
+
+Fix nested emojis and inline markdown elements failing to parse correctly inside of heading blocks.

packages/message-parser/src/grammar.pegjs

@@ -144,11 +144,12 @@ CodeChunk = text:$(!EndOfLine !"```" .)+ { return plain(text); }
  * #### Heading 4
  *
 */
-Heading = count:HeadingStart [ \t]+ text:HeadingChunk { return heading([text], count); }
+Heading = count:HeadingStart [ \t]+ text:HeadingChunk { return heading(text.map(v => Array.isArray(v) ? v[1] : v), count); }
 
 HeadingStart = value:"#" |1..4| { return value.length; }
 
-HeadingChunk = text:$(!EndOfLine .)+ { return plain(text); }
+HeadingChunk = text:(!EndOfLine Inline)+ { return text; }
+
 
 /**
  *

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

@@ -1,5 +1,5 @@
 import { parse } from '../src';
-import { heading, lineBreak, mentionChannel, paragraph, plain } from './helpers';
+import { emoji, heading, lineBreak, mentionChannel, paragraph, plain } from './helpers';
 
 test.each([
 	['# h1', [heading([plain('h1')], 1)]],
@@ -44,6 +44,10 @@ test.each([
 	['He####llo', [paragraph([plain('He####llo')])]],
 	['# Hello\n', [heading([plain('Hello')], 1), lineBreak()]],
 	['# # Hello\n', [heading([plain('# Hello')], 1), lineBreak()]],
+	['# :newspaper: Headline', [heading([emoji('newspaper'), plain(' Headline')], 1)]],
+	['## Hello :smile:', [heading([plain('Hello '), emoji('smile')], 2)]],
+	['### :smile: text :newspaper:', [heading([emoji('smile'), plain(' text '), emoji('newspaper')], 3)]],
+
 ])('parses %p', (input, output) => {
 	expect(parse(input)).toMatchObject(output);
 });