How do I test a Firebase Cloud Function that expects a user ID? [duplicate] - firebase

Question

I want to test a a cloud function that creates users.
In normal cases, inside the browser i generate an idToken and i send it to server via headers: Authorization : Bearer etcIdToken
But I want to test this function without the browser. In my mocha tests i have:
before(done => {
firebase = require firebase.. -- this is suppose to be like the browser lib.
admin = require admin..
idToken = null;
uid = "AY8HrgYIeuQswolbLl53pjdJw8b2";
admin.auth()
.createCustomToken(uid) -- admin creates a customToken
.then(customToken => {
return firebase.auth() -- this is like browser code. customToken get's passed to the browser.
.signInWithCustomToken(customToken) -- browser signs in.
.then(signedInUser => firebase.auth() -- now i want to get an idToken. But this gives me an error.
.currentUser.getIdToken())
})
.then(idToken_ => {
idToken = idToken_
done();
})
.catch(err => done(err));
})
The error i'm getting is:
firebase.auth(...).currentUser.getIdToken is not a function - getting the idToken like this works on client - and is documented here.
I tried directly with signedInUser.getIdToken(). Same problem:
signedInUser.getIdToken is not a function - not documented. just a test.
I think this is because firebase object is not intended for node.js use like i'm doing here. When signing in - stuff get's saved in browser local storage - and maybe this is why.
But the question still remains. How can i get an idToken inside node.js in order to be able to test:
return chai.request(myFunctions.manageUsers)
.post("/create")
.set("Authorization", "Bearer " + idToken) --- i need the idToken here - like would be if i'm getting it from the browser.
.send({
displayName: "jony",
email: "jony#gmail.com",
password: "123456"
})
am I approaching this wrong? I know that if i can get the idToken it will work. Do i rely need the browser for this? Thanks :)

Answer 1

From Exchange custom token for an ID and refresh token, you can transform a custom token to an id token with the api. Hence, you just have to generate a custom token first from the uid, then transform it in a custom token. Here is my sample:
const admin = require('firebase-admin');
const config = require('config');
const rp = require('request-promise');
module.exports.getIdToken = async uid => {
const customToken = await admin.auth().createCustomToken(uid)
const res = await rp({
url: `https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyCustomToken?key=${config.get('firebase.apiKey')}`,
method: 'POST',
body: {
token: customToken,
returnSecureToken: true
},
json: true,
});
return res.idToken;
};

Answer 2

L. Meyer's Answer Worked for me.
But, the rp npm package is deprecated and is no longer used.
Here is the modified working code using axios.
const axios = require('axios').default;
const admin = require('firebase-admin');
const FIREBASE_API_KEY = 'YOUR_API_KEY_FROM_FIREBASE_CONSOLE';
const createIdTokenfromCustomToken = async uid => {
try {
const customToken = await admin.auth().createCustomToken(uid);
const res = await axios({
url: `https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyCustomToken?key=${FIREBASE_API_KEY}`,
method: 'post',
data: {
token: customToken,
returnSecureToken: true
},
json: true,
});
return res.data.idToken;
} catch (e) {
console.log(e);
}
}

Answer 3

curl 'https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyPassword?key=<FIREBASE_KEY>' -H 'Content-Type: application/json'--data-binary '{"email": "test#test.com","password":"test","returnSecureToken":true}'
If this curl doesn't run, try running the same thing on Postman. It works!