COMMAND: `INVITE`?

[dlbltv]

@mortinso It seems to work, if you come up with any new tests, please try it.

[mortinso]

The wikipedia for IRC Commands defines it the following way:

So after trying on HexChat and looking at the behavior I noticed the following:

• If the channel exists and the user is part of it: Send invite, Notify User
• If the channel doesn't exist: Send Invite, Notify User
• If the channel exists and the user isn't part of it: Don't Invite, Don't Notify User
• If the nickname doesn't exist: Don't Invite, Don't Notify User

Regarding the mode, that's something we'll have to handle in the future when we implement operators.