Skip cache set if given username is invalid

Problem/Motivation

Currently, null data is cached if a wrong username is given.

Steps to reproduce

Enter a wrong username. The field would still save the data and cache the data with null.

Proposed resolution

Set the cache only if the data exists.

  public function getUserInformation(string $doUsername): User {
    $cid = 'do_username:user:' . $doUsername;

    // Check if the data exist. If not, retrieve, save, and return.
    $cachedData = $this->cache->get($cid);
    if ($cachedData) {
      return $cachedData->data;
    }
    $request = new UserCollectionRequest(["name" => $doUsername]);
    $userData = $this->client->getEntity($request);
    if ($userData->valid()) {
      $this->cache->set($cid, $userData->current());
    }
    return $userData->current();
  }

Remaining tasks

User interface changes

API changes

Data model changes