Inserting an a mention with insertItem adds an "undefined" before the denotation char

[lucasfindox]

Adding a mention manually via insertItem method adds an "undefined" before the '@' character

[csculley]

Hi, the "Add Mention Programatically" button on https://quill-mention.com/ is an example of using insertItem manually that doesn't seem to be adding undefined. If you can't figure out what's causing it, could you make a reproduceable example of this in a public repository? Thank you!

[aaronjparsons]

Ran into this as well, but after looking at the source for the page linked by @csculley, there is a denotationChar field missing from the data in the docs example.

From the docs:
insertItem({id: '123', value: 'My Mention'}, true)

From the source:
insertItem({denotationChar: '@', id: '123', value:' My Mention'}, true)

After adding denotationChar to the data to insert, it works as expected