Save chat messages from Facebook

facebook_chat_messages.js

var messages = document.getElementsByClassName('_3058 _ui9')
var name = document.getElementsByClassName('_673w')[0].getElementsByClassName('_3oh-')[0].innerText;

[...messages].map( (message) => {
    var out = '';
    out += message.classList.contains('_43by') ? 'Me: ' : name+': '; 
    var text = message.getElementsByClassName('_58nk');
	if (text.length) return out + text[0].innerText;

}).filter(message => !!message).join('\n')