[Vuejs]-Using vue-socket.io-extended, emit with vuex problem

You can prepend the variable with underscore and ignore it.

Or you could pass an empty object emitSendMsg({}, msgToSend)

Also, the object passed as first parameter to action is the context not dispatch and it is not optional.

If you need only dispatch you could use object destructuring emitSendMsg({ dispatch }, msgToSend)