fbLogin.js

export function loginWithFacebook(accessToken){
  return (dispatch,_,firebaseApp)=>{
    dispatch({ type: LOGGING_IN});
    const credential = firebase.auth.FacebookAuthProvider.credential(accessToken);
    firebaseApp.auth().signInWithCredential(credential).then((user) => {
      dispatch({ type: LOGGED_IN, user });
    }).catch((error) => {
      console.log(error);
    });
  }
}