'Invoke the view with an empty field and assert correctness.
The request will be a POST request from the given `user`, with POST
fields taken from `fields`, replacing the entry specified by
`empty_field` with the empty string. The response should have a 400
(bad request) status code and specify the invalid field and an error
message, and the Zendesk API should not have been invoked.'

def _test_bad_request_empty_field(self, user, fields, empty_field, zendesk_mock_class, datadog_mock):

    altered_fields = fields.copy()
    altered_fields[empty_field] = ''
    resp = self._build_and_run_request(user, altered_fields)
    self._assert_bad_request(resp, empty_field, zendesk_mock_class, datadog_mock)
