Google Sign-In with Passportjs not getting authenticated

I'm using Sails with Passport for authentication. I'm using passport-google-oauth(OAuth2Strategy) and passport-facebook for enabling Google Sign-in.

I'm not too well-versed with Passport, so pardon me if this is a rookie question. I've set up login via Facebook and it works just fine. With Google, I do receive an authorization code after allowing access to the app, but the I'm eventually not authenticated. I'm guessing the same code should work for both Facebook and Google since the strategies are both based on oauth2.

I'm not even sure what code to share, since I'm using the auto-generated code from sails-generate-auth, but do let me know if there's anything else I can share.

Any ideas on why this might be happening? The app is locally hosted but that's unlikely to be the problem since I am getting to the authorization stage anyway.

Solution

Alright, so this ultimately turned out to be a known issue with the API.

TL;DR: Enable the Google+ API and the Contacts API as mentioned here. (The Contacts API isn't required, as @AlexisN-o pointed out in the comments. My setup worked as desired with Contacts API disabled. This obviously depends on what scope you're using.)

I believe it's not a nice way of failing since this was an API error that was prevented from bubbling up. Anyway, I dug into passport.authenticate to figure out what was going wrong. This eventually calls the authenticate method defined in the package corresponding to the strategy (oauth2 in this case). In here (passport-google-oauth/lib/passport-google-oauth/oauth2.js) I found that the accessToken was indeed being fetched from Google, so things should be working. This indicated that there was a problem with the requests being made to the token urls. So I ventured a little further into passport-oauth2/lib/strategy.js and finally managed to log this error:

{ [InternalOAuthError: failed to fetch user profile]
  name: 'InternalOAuthError',
  message: 'failed to fetch user profile',
  oauthError: 
   { statusCode: 403,
     data: '{
        "error": {
            "errors": [{
                  "domain": "usageLimits",
                  "reason": "accessNotConfigured",
                  "message": "Access Not Configured. The API (Google+ API) is not enabled for your project. Please use the Google Developers Console to update your configuration.",
                  "extendedHelp": "https://console.developers.google.com" 
            }],
            "code": 403,
            "message": "Access Not Configured. The API (Google+ API) is not enabled for your project. Please use the Google Developers Console to update your configuration." 
      }
    }'
} }

This was the end of the hunt for me and the first result for the error search led to the correct answer. Weird fix though.