Use an empty object as default value of options for Google Sign in (#6844)

* Use an empty object as default value of options for Google Sign in

* add test case

* Update test case to specifically  for google auth

spec/index.spec.js

@@ -531,4 +531,27 @@ describe('server', () => {
       })
       .catch(done.fail);
   });
+
+  it('should not fail when Google signin is introduced without the optional clientId', done => {
+    const jwt = require('jsonwebtoken');
+
+    reconfigureServer({
+      auth: { google: {} }
+    })
+      .then(() => {
+        const fakeClaim = {
+          iss: 'https://accounts.google.com',
+          aud: 'secret',
+          exp: Date.now(),
+          sub: 'the_user_id',
+        };
+        const fakeDecodedToken = { header: { kid: '123', alg: 'RS256' } };
+        spyOn(jwt, 'decode').and.callFake(() => fakeDecodedToken);
+        spyOn(jwt, 'verify').and.callFake(() => fakeClaim);
+        const user = new Parse.User();
+        user.linkWith('google', { authData: { id: 'the_user_id', id_token: 'the_token' }})
+          .then(done);
+      })
+      .catch(done.fail);
+  });
 });

src/Adapters/Auth/google.js

@@ -113,7 +113,7 @@ async function verifyIdToken({ id_token: token, id }, { clientId }) {
 }
 
 // Returns a promise that fulfills if this user id is valid.
-function validateAuthData(authData, options) {
+function validateAuthData(authData, options = {}) {
   return verifyIdToken(authData, options);
 }