Added basic tests for template backends.

tests/requirements/base.txt

 bcrypt
 docutils
+jinja2
 # move to py2.txt when dropping Python 3.2
 mock
 numpy

tests/template_backends/forbidden/template_backends/hello.html

+Hu ho.

tests/template_backends/jinja2/template_backends/csrf.html

+{{ csrf_input }}

tests/template_backends/jinja2/template_backends/hello.html

+Hello {{ name }}!

tests/template_backends/template_strings/template_backends/csrf.html

+$csrf_input

tests/template_backends/template_strings/template_backends/hello.html

+Hello $name!

tests/template_backends/templates/template_backends/csrf.html

+{% csrf_token %}

tests/template_backends/templates/template_backends/hello.html

+Hello {{ name }}!

tests/template_backends/test_django.py

+from django.template.backends.django import DjangoTemplates
+
+from .test_dummy import TemplateStringsTests
+
+
+class DjangoTemplatesTests(TemplateStringsTests):
+
+    engine_class = DjangoTemplates
+    backend_name = 'django'

tests/template_backends/test_dummy.py

+# coding: utf-8
+
+from __future__ import unicode_literals
+
+from django.http import HttpRequest
+from django.middleware.csrf import CsrfViewMiddleware, get_token
+from django.template import TemplateDoesNotExist
+from django.template.backends.dummy import TemplateStrings
+from django.test import SimpleTestCase
+
+
+class TemplateStringsTests(SimpleTestCase):
+
+    engine_class = TemplateStrings
+    backend_name = 'dummy'
+    options = {}
+
+    @classmethod
+    def setUpClass(cls):
+        params = {
+            'DIRS': [],
+            'APP_DIRS': True,
+            'NAME': cls.backend_name,
+            'OPTIONS': cls.options,
+        }
+        cls.engine = cls.engine_class(params)
+
+    def test_from_string(self):
+        template = self.engine.from_string("Hello!\n")
+        content = template.render()
+        self.assertEqual(content, "Hello!\n")
+
+    def test_get_template(self):
+        template = self.engine.get_template('template_backends/hello.html')
+        content = template.render({'name': 'world'})
+        self.assertEqual(content, "Hello world!\n")
+
+    def test_get_template_non_existing(self):
+        with self.assertRaises(TemplateDoesNotExist):
+            self.engine.get_template('template_backends/non_existing.html')
+
+    def test_html_escaping(self):
+        template = self.engine.get_template('template_backends/hello.html')
+        context = {'name': '<script>alert("XSS!");</script>'}
+        content = template.render(context)
+
+        self.assertIn('&lt;script&gt;', content)
+        self.assertNotIn('<script>', content)
+
+    def test_csrf_token(self):
+        request = HttpRequest()
+        CsrfViewMiddleware().process_view(request, lambda r: None, (), {})
+
+        template = self.engine.get_template('template_backends/csrf.html')
+        content = template.render(request=request)
+
+        expected = (
+            '<input type="hidden" name="csrfmiddlewaretoken" '
+            'value="{}" />'.format(get_token(request)))
+
+        self.assertHTMLEqual(content, expected)
+
+    def test_no_directory_traversal(self):
+        with self.assertRaises(TemplateDoesNotExist):
+            self.engine.get_template('../forbidden/template_backends/hello.html')
+
+    def test_non_ascii_characters(self):
+        template = self.engine.get_template('template_backends/hello.html')
+        content = template.render({'name': 'Jérôme'})
+        self.assertEqual(content, "Hello Jérôme!\n")

tests/template_backends/test_jinja2.py

+import sys
+
+from unittest import skipIf
+
+# Jinja2 doesn't run on Python 3.2 because it uses u-prefixed unicode strings.
+if sys.version_info[:2] == (2, 7) or sys.version_info[:2] >= (3, 3):
+    try:
+        import jinja2
+    except ImportError:
+        jinja2 = None
+        Jinja2 = None
+    else:
+        from django.template.backends.jinja2 import Jinja2
+else:
+    jinja2 = None
+    Jinja2 = None
+
+from .test_dummy import TemplateStringsTests
+
+
+@skipIf(jinja2 is None, "this test requires jinja2")
+class Jinja2Tests(TemplateStringsTests):
+
+    engine_class = Jinja2
+    backend_name = 'jinja2'
+    options = {'keep_trailing_newline': True}