How to send requests with JSONs in unit tests

Question

I have code within a Flask application that uses JSONs in the request, and I can get the JSON object like so:

Request = request.get_json()

Answer 1

Changing the post to

response=self.app.post('/test_function', 
                       data=json.dumps(dict(foo='bar')),
                       content_type='application/json')

fixed it.

Thanks to user3012759.