How to test session in flask resource

Question

I'd like to test a resource. The response of that depends on a parameter in session (logged) To test this resource, I've wrote those tests: ``` import app import unittest class Test(unittest.TestCase): def setUp(self): self.app = app.app.test_client() def test_without_session(self): resp = self.app.get('/') self.assertEqual('without session', resp.data) def test_with_session(self): with self.app as c: with c.session_transaction() as sess: sess['logged'] = True resp = c.get('/') self.assertEqual('with session', resp.data) if __name__ == '__main__': unittest.main() ``` My app.py is this: ``` from flask import Flask, session app = Flask(__name__) @app.route('/') def home(): if 'logged' in session: return 'with session' return 'without session' if __name__ == '__main__': app.run(debug=True) ``` When i run the tests I have this error: ``` ERROR: test_pippo_with_session (__main__.Test) ---------------------------------------------------------------------- Traceback (most recent call last):…

Accepted Answer

If you did not set a custom `app.session_interface`, then you forgot to set a secret key:

```
def setUp(self):
    app.config['SECRET_KEY'] = 'sekrit!'
    self.app = app.app.test_client()
```

This just sets a mock secret key for the tests, but for your application to work you'll need to generate a production secret key, see the sessions section in the Quickstart documentation for tips on how to produce a good secret key.

Without a secret key, the default session implementation fails to create a session.

How to test session in flask resource

Solution

Problem