How to detect invalid IndexedDB (in Firefox incognito mode for example) when opening PouchDB?

pouch-init.js

// I am trying to open PouchDB normally, but this fails in Firefox Incognito mode
var db = new PouchDB('test');
// InvalidStateError
// I see the idb error callback being called if the open request fails
exports.idbError = function (callback) {
  return function (event) {
    var message = (event.target && event.target.error &&
      event.target.error.name) || event.target;
    callback(errors.error(errors.IDB_ERROR, message, event.type));
  };
};
// I want to catch this error and maybe switch to using memory provider, but do not see
// a way to attach error handler to the PouchDB function