Calling super method in Django TestCase causes RecursionError

Question

According to Django's document:

Warning

SimpleTestCase and its subclasses (e.g. TestCase, ...) rely on setUpClass() and tearDownClass() to perform some class-wide initialization (e.g. overriding settings). If you need to override those methods, don’t forget to call the super implementation:

class MyTestCase(TestCase):

    @classmethod
    def setUpClass(cls):
        super(MyTestCase, cls).setUpClass()
        ...

    @classmethod
    def tearDownClass(cls):
        ...
        super(MyTestCase, cls).tearDownClass()

......

I decided to follow this practice when writing tests:

class AuthorListViewTest(TestCase):

    @classmethod
    def setUpTestData(cls):
        number_of_authors = 13
        for author_num in range(number_of_authors):
            Author.objects.create(first_name='Christian %s' % author_num, last_name='Surname %s' % author_num,)
        super(AuthorListViewTest, cls).setUpTestData()

    # testing functions

But I get an RecursionError when running tests:

  <hundreds of identical lines omitted>
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 10, in setUpTestData
    super(AuthorModelTest, cls).setUpClass()
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/test/testcases.py", line 1025, in setUpClass
    cls.setUpTestData()
  File "/Users/sunqingyao/Documents/Projects/locallibrary/catalog/tests/test_models.py", line 9, in setUpTestData
    Author.objects.create(first_name='Big', last_name='Bob')
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/query.py", line 399, in create
    obj.save(force_insert=True, using=self.db)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/base.py", line 796, in save
    force_update=force_update, update_fields=update_fields)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/base.py", line 824, in save_base
    updated = self._save_table(raw, cls, force_insert, force_update, using, update_fields)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/base.py", line 908, in _save_table
    result = self._do_insert(cls._base_manager, using, fields, update_pk, raw)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/base.py", line 947, in _do_insert
    using=using, raw=raw)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/manager.py", line 85, in manager_method
    return getattr(self.get_queryset(), name)(*args, **kwargs)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/query.py", line 1043, in _insert
    query = sql.InsertQuery(self.model)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/sql/subqueries.py", line 177, in __init__
    super(InsertQuery, self).__init__(*args, **kwargs)
  File "/Users/sunqingyao/Envs/django_test/lib/python3.6/site-packages/django/db/models/sql/query.py", line 155, in __init__
    self.where = where()
RecursionError: maximum recursion depth exceeded

This error fixed after removing the super line.

Why is it? Should I stop calling the super implementation, which is suggested by the documentation?

Answer 1

From the traceback, it seems the setUpTestData calls setUpClass in parent class. But your code snippet calls setUpTestData instead, which is correct.