NodeMCU mode: Keyes NodeMCU OS: Mac OS X (macOS)
Install a serial driver for the NodeMCU from: http://www.wch.cn/download/CH341SER_MAC_ZIP.html
Plugin the NodeMCU and see if you can see it at /dev/tty.wchusbserialfd120
NOTE: If you can't find it at the above locations try ls /dev/cu.*
and see what else is available.
OSX Sierra Important Note: After upgrading to Sierra plugging in my NodeMUC I kept getting Kernel panics and the laptop would restart. To fix this I uninstalled the original drivers with the following commands, restarted and then re-installed from the link above.