get(key, callback)

[shaneing]

getData(key) {
  let d;
  this.storage.get(key, (error, data) => {
    if (error) {
      err(`AutoComplete::getData(key) - Error for getting ${key}`);
    }
    d = data;
  });
  return d;
}

the content of storage file:

{}

But, an error occurred

[jviotti]

I believe you figured it out already, but .get() is an async function, and therefore your getData function will return before that completes.