Checking flash messages in flask application nose tests

Question

On different input values posted to a url of my flask application, it flashes different messages, e.g. 'no data entered', 'invalid input', 'no record found', '3 records found'.

Can someone guide how can I write a nose test to check if the proper flash message is displayed? I guess the flash messages first goto the session ... how can we check session variables in nose-tests?

Thanks

Answer 1

The method of testing flashes with session['_flashes'] didn't work for me, because session object simply doesn't have '_flashes' attribute in my case:

with client.session_transaction() as session:
    flash_message = dict(session['_flashes']).get('warning')

KeyError: '_flashes'

It might be because most recent version of flask and other packages I use with Python 3.6.4 may work differently, I honestly don't know...

What worked for me is a simple and straightforward:

def test_flash(self):
    # attempt login with wrong credentials
    response = self.client.post('/authenticate/', data={
        'email': '[email protected]',
        'password': '1234'
    }, follow_redirects=True)
    self.assertTrue(re.search('Invalid username or password',
                    response.get_data(as_text=True)))

In my case the flash message was 'Invalid user name or password'.

I think it's also easier to read. Hope it helps those who encountered a similar issue