How to Catch Rate Limit errors?

Hi,

we use your great nodejs library to integrate with Google Drive. We wrap your library basically in https://github.com/simatec/ioBroker.backitup/blob/master/lib/googleDriveLib.js

Now we have some users that alw<ys get Rate Limiting errors and in fact these are ok, but something seems to be wrong because they are thrown as unhandled promise rejections in the end and are not catchable. I also did a dive through your code and basically yes it should work, but we still get these reports and also our Sentry instance shows them:

One case: https://sentry.iobroker.net/share/issue/cdcb2ff3d08042f7829bb551e73a7043/

Error: User Rate Limit Exceeded. Rate of requests for user exceed configured project quota. You may consider re-evaluating expected per-user traffic to the API and adjust project quota limits accordingly. You may monitor aggregate quota usage and adjust lim...
  File "/opt/iobroker/node_modules/gaxios/src/gaxios.ts", line 117, col 15, in Gaxios._request
  ?, in runMicrotasks
  File "internal/process/task_queues.js", line 97, col 5, in processTicksAndRejections
  File "/opt/iobroker/node_modules/google-auth-library/build/src/auth/oauth2client.js", line 343, col 18, in OAuth2Client.requestAsync
    r2 = await this.transporter.request(opts);

Second case: https://sentry.iobroker.net/share/issue/a325278331b14b81ac79337e65a6be86/

Error: Rate Limit Exceeded
  File "/opt/iobroker/node_modules/iobroker.backitup/node_modules/gaxios/src/gaxios.ts", line 117, col 15, in Gaxios._request
  File "internal/process/next_tick.js", line 68, col 7, in process._tickCallback

We use the most current version of googleaps here: 59.0.0

In fact yes we need to optimize the timing when (as it seems) we delete many files (https://github.com/simatec/ioBroker.backitup/blob/master/lib/scripts/75-googledrive.js#L43 …) but in fact the error should come to the callback as expected and should not be uncatchable thrown …

[sweetanalytics]

@Apollon77 https://github.com/googleapis/google-api-nodejs-client/issues/2495

[JustinBeckwith]

Greetings! I took a look at your code, and it has a few issues that could be leading to the problem here. Your code is mixing promises and call backs in some confusing ways. This code:

 deleteFile(folderOrFileId, fileName) {
        return new Promise((resolve, reject) => {
            if (folderOrFileId && !fileName) {
                this._getDrive()
                    .then(drive => drive.files.delete({fileId: folderOrFileId}, err => {
                        if (err) {
                            // Handle error
                            reject(err);
                        } else {
                            resolve();
                        }
                    }));
            } else {
                this.getFileOrFolderId(fileName, folderOrFileId)
                    .then(fileId => {
                        this._getDrive()
                            .then(drive => drive.files.delete({fileId}, err => {
                                if (err) {
                                    // Handle error
                                    reject(err);
                                } else {
                                    resolve();
                                }
                            }));
                    });
            }
        });

Could be simplified to:

async function deleteFile(folderOrFileId, fileName) {
  const drive = await this._getDrive()
  if (folderOrFileId && !fileName) {
    await drive.files.delete({fileId: folderOrFileId});
  } else {
    const fileId = await this.getFileOrFolderId(fileName, folderOrFileId);
    await drive.files.delete({fileId});
  }
}

When you call one of these methods as a promise, whether with .then chaining or async functions, it’s going to throw if you hit an exception. If you want to handle specific cases, you can always wrap this in a try/catch, and then look for err.response.status, which should tell you what caused this specific problem.