[MM-60408] Replaced chars with HTML entities in reminder posts

[raghavaggarwal2308]

Summary

• Replaced chars with HTML entities in reminder posts

Screenshots

Before:

After:

Ticket Link

Fixes https://mattermost.atlassian.net/browse/MM-60408

[AayushChaudhary0001]

@raghavaggarwal2308 This PR was reviewed and I found an issue regarding some markdowns
Please refer the below screenshots:-

on MS calendar

on MM

This seems to have a handling issue on Mattermost, please verify the same.

[Kshitij-Katiyar]

@raghavaggarwal2308 This PR was reviewed and I found an issue regarding some markdowns Please refer the below screenshots:-

on MS calendar

on MM

This seems to have a handling issue on Mattermost, please verify the same.

Hey @AayushChaudhary0001, The issue you reported is unrelated to this PR.
However a similar issue is found in the reminder post, A MSCalendar event with the ````test```$$qa$$new##few##` title is rendered as below

The issue you reported and the issue I have reported are related to the rendering of slack attachments only.

I looked into this issue but the MarkdownToHTMLEntities is working fine and converting the event subject to an equivalent HTML entity. The problem is with the rendering of slack attachment on the mattermost side.
@hanzei @wiggin77 Do you have an idea on this?

[hanzei]

That seems odd. Are we using a different rendering method in message attachments?

[Kshitij-Katiyar]

That seems odd. Are we using a different rendering method in message attachments?

@hanzei
We convert reserved Markdown characters to their HTML entity equivalents and then use bot.Poster's DMWithAttachments function to send the attachment which internally uses model.ParseSlackAttachment function on the MM side.

[Kshitij-Katiyar]

@raghavaggarwal2308 This PR was reviewed and I found an issue regarding some markdowns Please refer the below screenshots:-

on MS calendar

on MM

This seems to have a handling issue on Mattermost, please verify the same.

We have created an issue for this on the MM repo. The issue will be fixed once it's fixed on MM. We can move ahead with this PR for now

[AayushChaudhary0001]

Approving this PR, since a new Github issue has been created for the issue reported above