Any way to use Firebase google authentication in expo (create-react-native-app) without "eject" project

Question

As the question, for Login with google in firebase need to set google-service but if you create new react-native project with create-react-native-app there will have no "android" or "ios" folder (accept used "eject") so, anyone have a suggestion for me? However I've no idea for how to setting google-service in my project too (even I "eject" the project).

Answer 1

@brentvatne 's answer is a bit out of date. Here's how I got it working on Expo v27

Important bit: you can get your client ids with these instructions.

Just select your firebase app from the project dropdown on the google page.

const _loginWithGoogle = async function() {
  try {
    const result = await Expo.Google.logInAsync({
      androidClientId:"YOUR_ANDROID_CLIENT_ID",
      iosClientId:"YOUR_iOS_CLIENT_ID",
      scopes: ["profile", "email"]
    });

    if (result.type === "success") {
      const { idToken, accessToken } = result;
      const credential = firebase.auth.GoogleAuthProvider.credential(idToken, accessToken);
      firebase
        .auth()
        .signInAndRetrieveDataWithCredential(credential)
        .then(res => {
          // user res, create your user, do whatever you want
        })
        .catch(error => {
          console.log("firebase cred err:", error);
        });
    } else {
      return { cancelled: true };
    }
  } catch (err) {
    console.log("err:", err);
  }
};

Answer 2

It isn't necessary to make any changes to the android or ios folders in order to support Google sign in with firebase on an app built with Expo.

1. Follow the guide for configuring Google auth on the Expo docs
2. Use the approach described in Expo's Using Firebase guide, where it describes how to authenticate with Facebook, and swap out Google where needed.