How to check JS errors on remote sites via CasperJS.
casper.on('resource.received', function(resource) {
var status = resource.status;
if(status >= 400) {
casper.log('Resource ' + resource.url + ' failed to load (' + status + ')', 'error');
resourceErrors.push({
url: resource.url,
status: resource.status
});
}
});