HTTP response freshness testing
$ npm install fresh
var fresh = require('fresh')Check freshness of req and res headers.
When the cache is "fresh" true is returned, otherwise false is returned to indicate that the cache is now stale.
var req = { 'if-none-match': 'tobi' };
var res = { 'etag': 'luna' };
fresh(req, res);
// => false
var req = { 'if-none-match': 'tobi' };
var res = { 'etag': 'tobi' };
fresh(req, res);
// => true