NodeJS: Google Sign-In for server-side apps - node.js

Question

Following this documentation I succeed to perform Google Sign-In for server-side apps and have access to user's GoogleCalendar using Python on server side. I fail to do that with NodeJS.
Just in a nutshell - with Python I used the auth_code I've sent from the browser and got the credentials just like that:
from oauth2client import client
credentials = client.credentials_from_clientsecrets_and_code(
CLIENT_SECRET_FILE,
['https://www.googleapis.com/auth/drive.appdata', 'profile', 'email'],
auth_code)
Then I could store in DB the value of:
gc_credentials_json = credentials.to_json()
And generate credentials (yes it uses the refresh_token alone when it's needed):
client.Credentials.new_from_json(gc_credentials_json)
So I want to do the same using NodeJS:
easily generate credentials using just: CLIENT_SECRET_FILE, scopes and auth_code (just like I did with Python)
receive credentials using previous credentials value without analysing if the access token is expired - I prefer a ready (well tested by the community) solution
Thank you in advance!

Answer 1

I've implemented it using google-auth-library package.
Here is the function to retrieve the gcClient:
const performAuth = async () => {
const tokens = await parseTokenFromDB();
const auth = new OAuth2Client(
downloadedCredentialsJson.web.client_id,
downloadedCredentialsJson.web.client_secret
);
auth.on('tokens', async (newTokens) => {
updateDBWithNewTokens(newTokens);
});
await auth.setCredentials(tokens);
const gcClient = google.calendar({version: 'v3', auth});
return gcClient;
};
Here is the template for parseTokenFromCurrentDB function just to give the idea of its output:
const parseTokenFromCurrentDB = async () => {
// Put here your code to retrieve from DB the values below
return {
access_token,
token_type,
refresh_token,
expiry_date,
};
};
So using this implementation one can get gcClient:
const gcClient = await gc.getGcClient(org);
and use its methods, e.g.:
const gcInfo = await gc.getInfo(gcClient);
const events = await gc.getEvents(gcClient, calcPeriodInGcFormat());