[1.4.x] Fixed #19645 -- Added tests for TransactionMiddleware

Backpatch of f556df90be995a83b979cf875705d98521ab4dc7. Backpatching
these tests so that it will be easier to backpatch the fix for #19707.

tests/regressiontests/middleware/models.py

@@ -1 +1,11 @@
-# models.py file for tests to run.
+from django.db import models
+
+
+class Band(models.Model):
+    name = models.CharField(max_length=100)
+
+    class Meta:
+        ordering = ('name',)
+
+    def __unicode__(self):
+        return self.name

tests/regressiontests/middleware/tests.py

@@ -1,4 +1,5 @@
 # -*- coding: utf-8 -*-
+from __future__ import absolute_import, with_statement
 
 import gzip
 import re
@@ -7,15 +8,19 @@ import StringIO
 
 from django.conf import settings
 from django.core import mail
+from django.db import transaction
 from django.http import HttpRequest
 from django.http import HttpResponse
 from django.middleware.clickjacking import XFrameOptionsMiddleware
 from django.middleware.common import CommonMiddleware
 from django.middleware.http import ConditionalGetMiddleware
 from django.middleware.gzip import GZipMiddleware
-from django.test import TestCase, RequestFactory
+from django.middleware.transaction import TransactionMiddleware
+from django.test import TransactionTestCase, TestCase, RequestFactory
 from django.test.utils import override_settings
 
+from .models import Band
+
 class CommonMiddlewareTest(TestCase):
     def setUp(self):
         self.append_slash = settings.APPEND_SLASH
@@ -613,3 +618,45 @@ class ETagGZipMiddlewareTest(TestCase):
 ETagGZipMiddlewareTest = override_settings(
     USE_ETAGS=True,
 )(ETagGZipMiddlewareTest)
+
+class TransactionMiddlewareTest(TransactionTestCase):
+    """
+    Test the transaction middleware.
+    """
+    def setUp(self):
+        self.request = HttpRequest()
+        self.request.META = {
+            'SERVER_NAME': 'testserver',
+            'SERVER_PORT': 80,
+        }
+        self.request.path = self.request.path_info = "/"
+        self.response = HttpResponse()
+        self.response.status_code = 200
+
+    def test_request(self):
+        TransactionMiddleware().process_request(self.request)
+        self.assertTrue(transaction.is_managed())
+
+    def test_managed_response(self):
+        transaction.enter_transaction_management()
+        transaction.managed(True)
+        Band.objects.create(name='The Beatles')
+        self.assertTrue(transaction.is_dirty())
+        TransactionMiddleware().process_response(self.request, self.response)
+        self.assertFalse(transaction.is_dirty())
+        self.assertEqual(Band.objects.count(), 1)
+
+    def test_unmanaged_response(self):
+        transaction.managed(False)
+        TransactionMiddleware().process_response(self.request, self.response)
+        self.assertFalse(transaction.is_managed())
+        self.assertFalse(transaction.is_dirty())
+
+    def test_exception(self):
+        transaction.enter_transaction_management()
+        transaction.managed(True)
+        Band.objects.create(name='The Beatles')
+        self.assertTrue(transaction.is_dirty())
+        TransactionMiddleware().process_exception(self.request, None)
+        self.assertEqual(Band.objects.count(), 0)
+        self.assertFalse(transaction.is_dirty())