[2.1.x] Fixed #29449 -- Reverted "Fixed #28757 -- Allowed using contrib.auth forms without installing contrib.auth."

This reverts commit 3333d935d2914cd80cf31f4803821ad5c0e2a51d due to
a crash if USERNAME_FIELD isn't a CharField.

Backport of f3fa86a89b3b85242f49b2b9acf58b5ea35acc1f from master

1 files changed, 30 insertions, 110 deletions

diff --git a/tests/auth_tests/test_forms.py b/tests/auth_tests/test_forms.py
index 52d61cfe87..825138755d 100644
--- a/tests/auth_tests/test_forms.py
+++ b/tests/auth_tests/test_forms.py
@@ -1,9 +1,7 @@
 import datetime
 import re
-from importlib import reload
 from unittest import mock
 
-import django
 from django import forms
 from django.contrib.auth.forms import (
     AdminPasswordChangeForm, AuthenticationForm, PasswordChangeForm,
@@ -13,7 +11,7 @@ from django.contrib.auth.forms import (
 from django.contrib.auth.models import User
 from django.contrib.auth.signals import user_login_failed
 from django.contrib.sites.models import Site
-from django.core import mail, signals
+from django.core import mail
 from django.core.mail import EmailMultiAlternatives
 from django.forms.fields import CharField, Field, IntegerField
 from django.test import SimpleTestCase, TestCase, override_settings
@@ -29,24 +27,6 @@ from .models.with_integer_username import IntegerUsernameUser
 from .settings import AUTH_TEMPLATES
 
 
-def reload_auth_forms(sender, setting, value, enter, **kwargs):
-    if setting == 'AUTH_USER_MODEL':
-        reload(django.contrib.auth.forms)
-
-
-class ReloadFormsMixin:
-
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-        signals.setting_changed.connect(reload_auth_forms)
-
-    @classmethod
-    def tearDownClass(cls):
-        signals.setting_changed.disconnect(reload_auth_forms)
-        super().tearDownClass()
-
-
 class TestDataMixin:
 
     @classmethod
@@ -57,10 +37,9 @@ class TestDataMixin:
         cls.u4 = User.objects.create(username='empty_password', password='')
         cls.u5 = User.objects.create(username='unmanageable_password', password='$')
         cls.u6 = User.objects.create(username='unknown_password', password='foo$bar')
-        cls.u7 = ExtensionUser.objects.create(username='extension_client', date_of_birth='1998-02-24')
 
 
-class UserCreationFormTest(ReloadFormsMixin, TestDataMixin, TestCase):
+class UserCreationFormTest(TestDataMixin, TestCase):
 
     def test_user_already_exists(self):
         data = {
@@ -196,25 +175,19 @@ class UserCreationFormTest(ReloadFormsMixin, TestDataMixin, TestCase):
         )
 
     def test_custom_form(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.ExtensionUser'):
-            from django.contrib.auth.forms import UserCreationForm
-            self.assertEqual(UserCreationForm.Meta.model, ExtensionUser)
-
-            class CustomUserCreationForm(UserCreationForm):
-                class Meta(UserCreationForm.Meta):
-                    fields = UserCreationForm.Meta.fields + ('date_of_birth',)
+        class CustomUserCreationForm(UserCreationForm):
+            class Meta(UserCreationForm.Meta):
+                model = ExtensionUser
+                fields = UserCreationForm.Meta.fields + ('date_of_birth',)
 
-            data = {
-                'username': 'testclient',
-                'password1': 'testclient',
-                'password2': 'testclient',
-                'date_of_birth': '1988-02-24',
-            }
-            form = CustomUserCreationForm(data)
-            self.assertTrue(form.is_valid())
-        # reload_auth_forms() reloads the form.
-        from django.contrib.auth.forms import UserCreationForm
-        self.assertEqual(UserCreationForm.Meta.model, User)
+        data = {
+            'username': 'testclient',
+            'password1': 'testclient',
+            'password2': 'testclient',
+            'date_of_birth': '1988-02-24',
+        }
+        form = CustomUserCreationForm(data)
+        self.assertTrue(form.is_valid())
 
     def test_custom_form_with_different_username_field(self):
         class CustomUserCreationForm(UserCreationForm):
@@ -288,30 +261,6 @@ class UserCreationFormTest(ReloadFormsMixin, TestDataMixin, TestCase):
             ['The password is too similar to the first name.'],
         )
 
-    def test_with_custom_user_model(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.ExtensionUser'):
-            data = {
-                'username': 'test_username',
-                'password1': 'test_password',
-                'password2': 'test_password',
-            }
-            from django.contrib.auth.forms import UserCreationForm
-            self.assertEqual(UserCreationForm.Meta.model, ExtensionUser)
-            form = UserCreationForm(data)
-            self.assertTrue(form.is_valid())
-
-    def test_customer_user_model_with_different_username_field(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.CustomUser'):
-            from django.contrib.auth.forms import UserCreationForm
-            self.assertEqual(UserCreationForm.Meta.model, CustomUser)
-            data = {
-                'email': 'testchange@test.com',
-                'password1': 'test_password',
-                'password2': 'test_password',
-            }
-            form = UserCreationForm(data)
-            self.assertTrue(form.is_valid())
-
 
 # To verify that the login form rejects inactive users, use an authentication
 # backend that allows them.
@@ -677,7 +626,7 @@ class PasswordChangeFormTest(TestDataMixin, TestCase):
         self.assertEqual(form.cleaned_data['new_password2'], data['new_password2'])
 
 
-class UserChangeFormTest(ReloadFormsMixin, TestDataMixin, TestCase):
+class UserChangeFormTest(TestDataMixin, TestCase):
 
     def test_username_validity(self):
         user = User.objects.get(username='testclient')
@@ -751,51 +700,22 @@ class UserChangeFormTest(ReloadFormsMixin, TestDataMixin, TestCase):
         self.assertEqual(form.initial['password'], form['password'].value())
 
     def test_custom_form(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.ExtensionUser'):
-            from django.contrib.auth.forms import UserChangeForm
-            self.assertEqual(UserChangeForm.Meta.model, ExtensionUser)
-
-            class CustomUserChangeForm(UserChangeForm):
-                class Meta(UserChangeForm.Meta):
-                    fields = ('username', 'password', 'date_of_birth')
-
-            data = {
-                'username': 'testclient',
-                'password': 'testclient',
-                'date_of_birth': '1998-02-24',
-            }
-            form = CustomUserChangeForm(data, instance=self.u7)
-            self.assertTrue(form.is_valid())
-            form.save()
-            self.assertEqual(form.cleaned_data['username'], 'testclient')
-            self.assertEqual(form.cleaned_data['date_of_birth'], datetime.date(1998, 2, 24))
-        # reload_auth_forms() reloads the form.
-        from django.contrib.auth.forms import UserChangeForm
-        self.assertEqual(UserChangeForm.Meta.model, User)
-
-    def test_with_custom_user_model(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.ExtensionUser'):
-            from django.contrib.auth.forms import UserChangeForm
-            self.assertEqual(UserChangeForm.Meta.model, ExtensionUser)
-            data = {
-                'username': 'testclient',
-                'date_joined': '1998-02-24',
-                'date_of_birth': '1998-02-24',
-            }
-            form = UserChangeForm(data, instance=self.u7)
-            self.assertTrue(form.is_valid())
+        class CustomUserChangeForm(UserChangeForm):
+            class Meta(UserChangeForm.Meta):
+                model = ExtensionUser
+                fields = ('username', 'password', 'date_of_birth',)
 
-    def test_customer_user_model_with_different_username_field(self):
-        with override_settings(AUTH_USER_MODEL='auth_tests.CustomUser'):
-            from django.contrib.auth.forms import UserChangeForm
-            self.assertEqual(UserChangeForm.Meta.model, CustomUser)
-            user = CustomUser.custom_objects.create(email='test@test.com', date_of_birth='1998-02-24')
-            data = {
-                'email': 'testchange@test.com',
-                'date_of_birth': '1998-02-24',
-            }
-            form = UserChangeForm(data, instance=user)
-            self.assertTrue(form.is_valid())
+        user = User.objects.get(username='testclient')
+        data = {
+            'username': 'testclient',
+            'password': 'testclient',
+            'date_of_birth': '1998-02-24',
+        }
+        form = CustomUserChangeForm(data, instance=user)
+        self.assertTrue(form.is_valid())
+        form.save()
+        self.assertEqual(form.cleaned_data['username'], 'testclient')
+        self.assertEqual(form.cleaned_data['date_of_birth'], datetime.date(1998, 2, 24))
 
     def test_password_excluded(self):
         class UserChangeFormWithoutPassword(UserChangeForm):