fix: parsing underscores in the email of user mention

[eh2077]

Fixed Issues

$ Expensify/App#19957

Tests

1. Go to a chat and add a comment @_concierge_@expensify.com
2. Verify that App doesn’t crash and _concierge_ is not rendered as italic

QA

Same as test

[allroundexperts]

@eh2077 Can we add this for other cases such as bold text?

[eh2077]

@eh2077 Can we add this for other cases such as bold text?

It's a good point. I also dug this but I found that this issue happens only on underscore _ because underscore _ is treated as word character in JavaScript regex but * and ~ are not word characters.

* and ~ are not valid characters for the email of user mention. For example, input like @*concierge*@expensify.com won’t be parsed as user mention because *concierge*@expensify.com is not a valid email.

So, I think we don't need to change the regex for bold and strikethrough rule.

[allroundexperts]

Looks good.
cc @dangrous

[dangrous]

I'm happy to review this but it looks like it should be @johnmlee101 based on the linked issue?

[allroundexperts]

I'm happy to review this but it looks like it should be @johnmlee101 based on the linked issue?

Correct @dangrous. If you can assign him, then that would be awesome!