Testing flask_wtf/wtforms with pytest - python-3.x

Question

I'd like to test a POST route that processes a non-trivial form (by working with flask.request.form). I didn't really find a good tutorial for this somehow as most pass json data rather than form (or is it the same?).
I tried to write the code in the following way:
import pytest
import app #app.app is the Flask app
#pytest.fixture
def client():
app.app.config['TESTING'] = True
with app.app.test_client() as client:
with app.app.app_context():
yield client
def test_route_webapp_post(client):
form = app.forms.ImputeForm.make_form(data_dict=app.data_dictionary.data_dict,
numeric_fields=app.binaries_dict['numeric_mappers'].keys(),
recordname2description=app.binaries_dict['recordname2description'])
rv = client.post('/web_app',form=form)
assert rv.status_code==200
The form is generated dynamically and I don't always know ahead of time what are the fields:
from flask_wtf import FlaskForm
from wtforms import SelectField, DecimalField, BooleanField
class ImputeForm(FlaskForm):
#classmethod
def make_form(cls, data_dict, numeric_fields, recordname2description, request_form=None):
for key in numeric_fields:
setattr(cls, key, DecimalField(id=key, label=recordname2description[key].split('(')[0]))
setattr(cls, 'mask_' + key, BooleanField(label='mask_' + key))
for key in data_dict:
setattr(cls, key, SelectField(id=key, label=recordname2description[key],
choices=[(-1, 'None selected')]+list(data_dict[key].items())))
setattr(cls, 'mask_' + key, BooleanField(label='mask_' + key))
instance = cls(request_form)
return instance
But this doesn't really work as I can't make a form inside the test case and get
E RuntimeError: Working outside of request context.
E
E This typically means that you attempted to use functionality that needed
E an active HTTP request. Consult the documentation on testing for
E information about how to avoid this problem.
So what is the proper approach to testing my form (in particular I am ok with sending an empty one)?

Answer 1

The correct way is to create a python dictionary and pass it as "data", not to try to create a form.
In particular case this involved making a new function:
def make_from_data( data_dict, numeric_fields):
data = dict()
for key in numeric_fields:
data[key]='234'
data['mask_' + key]='y'
for key in data_dict:
data[key]=-1
data['mask_' + key]='y'
return data
and passing it as follows:
def test_route_webapp_post(client):
data = make_from_data(data_dict=app.data_dictionary.data_dict,
numeric_fields=app.binaries_dict['numeric_mappers'].keys())
rv = client.post('/web_app',data=data)
assert rv.status_code==200