To add to this, at some point the community, even Elixir codebase, settled on do_send_message as a convention but today we see it as a bad practice. We are trying our best to not use do_ prefixes in Elixir and use proper function names for them, even if it ends up being the original name with extra information, for example, check_shortname_and_send_message.

You can pattern match the handle_command function to drop the first if

defp handle_command({"msg", "remove-trigger", cmd}, {%{data: %{"author" => %{"id" => 1234}}}, state}) do
   # handle author 1234  
end
defp handle_command({"msg", "remove-trigger", cmd}, {payload, state}) do
  # No-op because you have no else
end

For the second if I would drop the call to Message.has/1 (assuming Message.get/1 returns nil for no message)

shortname = String.split(cmd, " ") |> List.first
do_send_message(Messages.get(shortname))

Then have a function deal with the presence or lack of message

defp do_send_message(nil) do
  send_message "unknown Message", {payload, state}
end
defp do_send_message(info) do
  trigger = …
end

Keep going by creating functions that handle each situation and try to come up with names that reveal the intent of each step (do_send_message is a terrible function name but because naming is hard, you get to solve that )

Thanks a lot guys, this really helped me. It’s really easy for me to forget how powerful the pattern matching just is. I know Rust’s pattern matching which is pretty cool already, but this is way more powerful.