archive.js

var Zip = require('node-7z');
var async = require('async');
var fs = require('fs');

var archive = new Zip();

// Polyfill String.prototype.endsWith
if (!String.prototype.endsWith) {
	Object.defineProperty(String.prototype, 'endsWith', {
		enumerable: false,
		configurable: false,
		writable: false,
		value: function (searchString, position) {
			position = position || this.length;
			position = position - searchString.length;
			return this.lastIndexOf(searchString) === position;
		}
	});
}

var now = new Date();
// set threshold to the beginning of the month
var threshold = new Date(now.getFullYear(), now.getMonth(), 1);

var pending = {};

var filenames = fs.readdirSync('.');
filenames.forEach(function(filename) {
	if (filename.endsWith('.log')) {
		var params = filename.split('-');
		var timestamp = new Date(params[1], params[2] - 1, params[3]);

		if (timestamp < threshold) {
			var archivename = params[1] + '-' + params[2] + '.7z';
			if (!pending[archivename]) pending[archivename] = [];
			pending[archivename].push(filename);
		}
	}
});

for (var archivename in pending) if (pending.hasOwnProperty(archivename)) {
	var filenames = pending[archivename];
	archive.add(archivename, filenames).catch(function (error) {
		console.error(error);
	}).then(function () {
		filenames.forEach(function (filename) {
			fs.unlink(filename);
		});
	});
}