CODEWITHSUNDEEP
pythonunit-testingsessiontestingflask
Nate Brennand
Nate Brennand

Reputation: 1508

Flask unittesting session decorator

I've been trying to test a Flask API, I was able to minimize the boilerplate for each test significantly by inheriting from a template class which covers app and database connections. What I haven't figured out is how to set a session object before each test.

I've seen the example of how to handle test sessions but I'd like to hide it in a decorator or in the unittest class setup if possible.

Unittest class setup:

class TestingTemplate(unittest.TestCase):

    @classmethod
    def setUpClass(self):
        """ Sets up a test database before each set of tests """
        setup_db('localhost', 28015, 'TEST',
            datasets = test_dataset,
            app_tables = test_tables)
        self.rdb = rethinkdb.connect(
                host = 'localhost',
                port = 28015,
                db = 'TEST')
        self.rdb.use('TEST')
        app.config['RDB_DB'] = 'TEST'
        self.app = app.test_client()

Failing test class:

def admin_session(fn):
    def run_test(self):
        with self.app.session_transaction() as sess:
            sess['role'] = 'admin'
        fn(self)
    return run_test


class TestReview(template.TestingTemplate):
    """ Tests the API endpoints associated with handling reviews. """


    @admin_session
    def test_create_success(self):
        """ Tests a successful review creation """
        # creating review
        review = {'company': 'test', 'rating':10}
        resp = self.app.post('/review/create/123', data=json.dumps(review))

        # testing creation
        self.assertEqual(resp.status_code, 201)
        resp_data = json.loads(resp.data)
        self.assertEqual(resp_data['message'], 'review created')

Error thrown:

======================================================================
ERROR: test_create_success (test_reviews.TestReview)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/vagrant/src/server/testing/test_reviews.py", line 11, in run_test
    with self.app.session_transaction() as sess:
  File "/usr/lib/python2.7/contextlib.py", line 17, in __enter__
    return self.gen.next()
  File "/usr/local/lib/python2.7/dist-packages/flask/testing.py", line 74, in session_transaction
    raise RuntimeError('Session backend did not open a session. '
RuntimeError: Session backend did not open a session. Check the configuration

Any ideas on how to set a session cookie before each test without the double with statement boilerplate?

Upvotes: 2

Views: 2365

Answers (1)

DazWorrall
DazWorrall

Reputation: 14210

I tend to do this sort of thing with a helper method to replace the get/post methods:

class MyTestCase(unittest.TestCase):

    def request_with_role(self, path, method='GET', role='admin', *args, **kwargs):
        '''
        Make an http request with the given role in the session
        '''
        with self.app.test_client() as c:
            with c.session_transaction() as sess:
                sess['role'] = role
            kwargs['method'] = method
            kwargs['path'] = path
            return c.open(*args, **kwargs)

    def test_my_thing(self):
        review = {'company': 'test', 'rating':10}
        resp = self.request_with_role(
            '/review/create/123',
            method='POST',
            data=json.dumps(review),
        )
        ....

You could also have something like request_as_user, which takes your user object and sets up the session correctly for that user:

session['_id'] = user.id
session['role'] = user.role

Upvotes: 2

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