Bad interaction between Italic Extension and mentions plugin

[benjie]

Description

Easiest way to reproduce:

1/ Edit fake-users.ts so one of the usernames contains an underscore, e.g. change purplebird177 to purple_bird177:

remirror/@remirror/showcase/src/data/fake-users.ts

Line 112 in d743253

username: 'purplebird177',

2/ yarn build

3/ Run the Next example: cd examples/with-next && yarn dev

4/ visit http://localhost:3000/editor/rich-social

5/ Auto-complete @purple_bird177 (note the underscore) and then press *

Expected: text should read @purple_bird177 *

Actual: text reads @purplbird177

This is with the rich editor but you can reproduce it with just the ItalicExtension:

  const extensions = useMemo(() => {
    return [{ extension: new ItalicExtension(), priority: 2 }];
  }, []);

GIF:

Possible Fix

Don't have italic markdown match in the middle of words. I.e. the following should not match an underscore for italic purposes:

• @_user
• @user_name
• user_name
• https://website.com/web_page

I think it should also not match "special" text like links, mentions, tags; so the following should also not match for italic purposes:

• @user_
• @__xuorig__
• #tag_
• http://site.com/_

Checklist

• I have read the contributing document.

[ifiokjr]

This still needs to be addressed. Again, I'll add a failing test case and then create a fix.