v5.0.* Code Block Highlighting No Longer Working As Expected

[jadanah]

There seems to be an issue when rendering a code block

e.g. if I post to api/v1/chat.postMessage

{"channel":"testing","text":"```yaml\r\n\"Channel\": \"testing\"\r\n\"Guid\": \"66a242b6-6dc4-4c60-81c2-964d274e39df\"\r\n```"}

response:

{"ts":1658738843882,"channel":"testing","message":{"alias":"","msg":"```yaml\r\n\"Channel\": \"testing\"\r\n\"Guid\": \"66a242b6-6dc4-4c60-81c2-964d274e39df\"\r\n```","attachments":[],"parseUrls":true,"groupable":false,"ts":"2022-07-25T08:47:23.748Z","u":{"_id":"f7KxnCCiJn96KAWFG","username":"ukgd.toolkit","name":"UKGD ToolKit"},"rid":"7BtzSPWzf2MQAJkbD","unread":true,"_id":"u9HQTfxNpTarvXSyZ","_updatedAt":"2022-07-25T08:47:23.829Z","urls":[],"mentions":[],"channels":[],"md":[{"type":"PARAGRAPH","value":[{"type":"PLAIN_TEXT","value":"```yaml"}]},{"type":"PARAGRAPH","value":[{"type":"PLAIN_TEXT","value":"\"Channel\": \"testing\""}]},{"type":"PARAGRAPH","value":[{"type":"PLAIN_TEXT","value":"\"Guid\": \"66a242b6-6dc4-4c60-81c2-964d274e39df\""}]},{"type":"PARAGRAPH","value":[{"type":"PLAIN_TEXT","value":"```"}]}]},"success":true}

without legacy messages:

then the code block wont be highlighted unless I activate "Enable Legacy Messages"

with legacy messages:

Version
5.0.0-rc.12
Apps Engine Version
1.33.0
Node Version
v14.19.3
Database Migration
279 (July 25, 2022 9:14 AM)
MongoDB
5.0.9 / wiredTiger (oplog Enabled)
Commit Details
HEAD: (6a0fea4e1)
Branch: HEAD

Originally posted by @jadanah in #23971 (comment)

[jadanah]

Tested also against version 5.0.1 and issue remains, the only workaround is to navigate to /account/preferences and then enable Use legacy message templates within the Global section.

[ebyrne242]

I noticed in 5.0.3 that if you put the code block markers on a separate line, it does render the code block properly.

I've also noticed this prior to 5.0 on the android app, not sure exactly when it started. I assume the difference is that there is no option to use the legacy message parser on mobile apps. I believe this bug actually predates 5.0, it's just that users' default message parser was changed when 5.0 was released.

[hugocostadev]

Fixed by RocketChat/fuselage#739

[ebyrne242]

Just updated to 5.1.2, which does not fix this.

Here's a screenshot example: First block is three backticks, newline, foo, newline, three backticks. Second block is three backticks, foo, three backticks.

With the new message template:

With the legacy message template, both code blocks display properly.

[jadanah]

Do we know if this will be in the 5.2.0 release?

[ebyrne242]

Apparently not, as 5.3.0 is still broken. Do we know if it will be in 5.4.0?