Unit testing of OAuth on Flask

I'm new to coding and I feel really stuck. I decided to unit test my micro Flask app. I use "Google sign in" to authenticate my users, but I'm not able to get through the Google authentication and assert what is really on the page. I have no idea if I need to mock, play with the session or application context.

Here is the code for authentication process:

def login_required(f):
    @wraps(f)
    def decorated_function(*args, **kwargs):
        user = dict(session).get('profile', None)
        if user is not None:
            email = session['profile']['email']
        else:
            email = None
        if user:
            return f(*args, **kwargs)

        return render_template('login.html', email=email)

    return decorated_function

@app.route('/login/')
def login():
    google = oauth.create_client('google')  # create the google oauth client
    redirect_uri = url_for('authorize', _external=True)
    return google.authorize_redirect(redirect_uri)

@app.route('/authorize')
    def authorize():
        google = oauth.create_client('google')  # create the google oauth client
        token = google.authorize_access_token()  # Access token from google (needed to get user info)
        resp = google.get('userinfo')  # userinfo specificed in the scrope
        user_info = resp.json()
        # Loading and cleaning all user emails
        auth_users = db.session.query(users.email).all()
        auth_users = [str(i).strip("(),'") for i in auth_users]
        # Checking if user is in the list
        if user_info['email'] in auth_users:
            flash("Boli ste úspešne prihlásený.", category="success")
        else:
            flash("Nemáte práva na prístup.", category="primary")
            return redirect('/')
        session['profile'] = user_info
        # make the session pernament so it keeps existing after broweser gets closed
        session.permanent = True
        return redirect('/')

The test structure look like this:

class Uvo_page(unittest.TestCase):

    def setUp(self):
        self.client = app.test_client(self)
        self.user_info = {'email': 'xxx'}
        self.auth_users = ['xxx', 'yyy']

   # UVO page shows results
    def test_uvo_page_show_results(self):
        response = self.client.get('/show/1',
                                   content_type='html/text',
                                   follow_redirects=True)
        test_string = bytes('Sledované stránky', 'utf-8')
        self.assertTrue(test_string in response.data)

I thought that by defining the "user_info" it will be used for authentication evaluation. Instead of it it does not continue to "/authorize" and authentication, but stays on the login page.