CODEWITHSUNDEEP
djangotestingtransactions
r_zelazny
r_zelazny

Reputation: 557

How to test a Django view which has transaction.atomic(using=myDb)?

I am trying to test a django view that includes a transaction; in particular, I specify which db I want to use by transaction.atomic(using=myDb). However, when I run my test I get django.db.utils.ConnectionDoesNotExist: The connection myDb doesn't exist.

Is there any way to test the view given that I'm not hitting myDb in the test? Thanks for your help!

Trackeback:

    Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\django\db\utils.py", line 176, in ensure_defaults
    conn = self.databases[alias]
KeyError: 'myDb'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "Z:\web-django-2\web-django\src\revisorsite\track\tests.py", line 92, in test_redirect_on_edit
    response = Add.as_view()(request)
  File "C:\Python34\lib\site-packages\django\views\generic\base.py", line 68, in view
    return self.dispatch(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\django\utils\decorators.py", line 67, in _wrapper
    return bound_func(*args, **kwargs)
  File "Z:\web-django-2\web-django\src\revisorsite\login\decorators.py", line 8, in wrap
    return function(request, *args, **kwargs)
  File "C:\Python34\lib\site-packages\django\utils\decorators.py", line 63, in bound_func
    return func.__get__(self, type(self))(*args2, **kwargs2)
  File "C:\Python34\lib\site-packages\django\views\generic\base.py", line 88, in dispatch
    return handler(request, *args, **kwargs)
  File "Z:\web-django-2\web-django\src\revisorsite\track\views.py", line 47, in post
    transaction.set_autocommit(False, using='myDb')
  File "C:\Python34\lib\site-packages\django\db\transaction.py", line 35, in set_autocommit
    return get_connection(using).set_autocommit(autocommit)
  File "C:\Python34\lib\site-packages\django\db\transaction.py", line 21, in get_connection
    return connections[using]
  File "C:\Python34\lib\site-packages\django\db\utils.py", line 208, in __getitem__
    self.ensure_defaults(alias)
  File "C:\Python34\lib\site-packages\django\db\utils.py", line 178, in ensure_defaults
    raise ConnectionDoesNotExist("The connection %s doesn't exist" % alias)
django.db.utils.ConnectionDoesNotExist: The connection myDb doesn't exist

Upvotes: 1

Views: 2777

Answers (2)

U V
U V

Reputation: 11

Below solution is working fine for me

from unittest.mock import MagicMock, patch
patch('django.db.transaction.atomic', return_value = MagicMock())

Upvotes: 1

r_zelazny
r_zelazny

Reputation: 557

Figured it out, guys. The trick is to specify the db being used with a variable. The DATABASES key returns a different list depending on whether the code is running as a test or normally.

from django.conf import settings
if 'myDb' in settings.DATABASES:
    db = 'myDb'
else:
    db = 'default'
with transaction.atomic(using=db):
    ...

Upvotes: 3

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