`Service_.prototype.hasAccess` doesn't set `this.lastError_` if `canGetToken` is `false`

[jonnybolton16]

After attempting to obtain an access token using service.getAccessToken(), I am accessing service.lastError_ in the catch block. However, this is undefined. Having looked at the source code, I see service.lastError_ is only assigned if canGetToken is true.

I believe in this case canGetToken is false because I haven't authenticated yet. Actually, I have, but my userProperties got cleared which has lost the stored token information; I need my catch block to re-run the authentication.

Is it possible for the source code to be amended, so that service.lastError_ gets assigned if canGetToken is false?

For context, this is my current code

function getAccessToken_() {
  try {
    return monzoService.getAccessToken();
  } catch {
    const msg = monzoService.lastError_.message;
    if (msg.includes('Client not found')) {
      ...obtain correct Client ID from user...
      monzoService = getMonzoService_();
      return getAccessToken_()
    } else if (msg.includes('Could not authenticate with provided credentials')) {
      ...obtain correct Client secret from user...
      monzoService = getMonzoService_();
      return getAccessToken_()
    } else if (msg.includes('Bad refresh token')) {
      reauthorise_();
    } else {
      throw new Error(msg);
    }
  }
}

Ideally msg will have some flag that will tell me I need to run reauthorise_, when canGetToken is false.

[jonnybolton16]

To add further to this issue, is there a way to check that the stored ID/secret are correct, before asking to reauth?

I'm finding that reauthorisation is required, but the stored client ID (which presumably has been edited) does not match a valid account - you only discover this after clicking the authorisation link. It would be neat if this could be verified before presenting the user with the authorisation link.

One way to test this would be to send an API request in the same manner as when refreshing an expired access token - then service.lastError_ could be used to identify an invalid client ID.