How to tell which access token was refreshed

Question

Using the following event, my backend is notified when an access token is refreshed.

oauth2client.on('tokens', (tokens) => {
  if (tokens.refresh_token) {
    // store the refresh_token in my database!
    console.log(tokens.refresh_token);
  }
  console.log(tokens.access_token);
});

But is there a way to know the predecessor of new access token? I store multiple couples of the access token and refresh token in DB(multiple users/accounts), where all of them are used to get data in parallel.

How can I update expired access token, stored in my DB, with the newer one? I could, of course, keep using the old access token and never update it, as the library is able to get a new one on every request, but this will make too many unnecessary requests.

Answer 1

I've figured it out. The oauth2Client object contains credentials property which has the old access_token. So I just check it like this:

if (oauth2Client.credentials.access_token) {
    // update it in DB
}