Flasher.js never gets a mention, but has, for me at least, become a foolproof way to flash ESP8266 with Espruino. I rarely if ever use the esptool.py now. Your mileage may vary but I'd recommend trying it, especially if just starting out.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
Flasher.js never gets a mention, but has, for me at least, become a foolproof way to flash ESP8266 with Espruino. I rarely if ever use the esptool.py now. Your mileage may vary but I'd recommend trying it, especially if just starting out.