profile.ts

getUserProfile(): Promise<firebase.database.Reference> {
  return new Promise((resolve, reject) => {
    firebase.auth().onAuthStateChanged(user => {
      if (user) {
        const userProfile = firebase.database().ref(`/userProfile/${user.uid}`);
        resolve(userProfile)
      } else {
        reject(false)
      }
    });
  });
}