(intermediate value)(intermediate value)(intermediate value).toLowerCase is not a function

[theeSpark]

A bot that has a command for disconnecting from a channel, checks if sender is the channel its in (basically if the command is sent by the streamer.)

Actual behaviour: Basically just throws an error crashing the bot.

Expected behaviour: Should part from the selected channel.

Error log:

node_modules\tmi.js\lib\utils.js:75
        var channel = (str ? str : "").toLowerCase();
                                       ^

TypeError: (intermediate value)(intermediate value)(intermediate value).toLowerCase is not a function

Server configuration

• Operating system: Windows 10
• Node version (if applicable): Latest
• NPM version (if applicable): Latest
• tmi.js version: Latest

[AlcaDesign]

How are you using .part?

[theeSpark]

client.part(channel); (channel is the first value in the chat event.)

[AlcaDesign]

You need to verify that channel is a string and/or at least a falsy value.