added testcases

tests/browsable_api/multiple_template_engines.py

@@ -0,0 +1,16 @@
+TEMPLATES = [
+    {
+        "BACKEND": "django_jinja.backend.Jinja2",
+        "APP_DIRS": True,
+        "OPTIONS": {
+            "match_extension": ".html",
+        }
+    },
+    {
+        'BACKEND': 'django.template.backends.django.DjangoTemplates',
+        'APP_DIRS': True,
+        'OPTIONS': {
+            "debug": True,  # We want template errors to raise
+        }
+    },
+]

tests/browsable_api/test_browsable_api.py

@@ -1,8 +1,11 @@
 from django.contrib.auth.models import User
-from django.test import TestCase, override_settings
+from django.test import Client, TestCase, override_settings
+from jinja2.exceptions import TemplateSyntaxError
 
 from rest_framework.test import APIClient
 
+from .multiple_template_engines import TEMPLATES
+
 
 @override_settings(ROOT_URLCONF='tests.browsable_api.auth_urls')
 class DropdownWithAuthTests(TestCase):
@@ -72,3 +75,29 @@ class NoDropdownWithoutAuthTests(TestCase):
         response = self.client.get('/')
         content = response.content.decode()
         assert '<li class="dropdown">' not in content
+
+
+@override_settings(ROOT_URLCONF='tests.browsable_api.auth_urls')
+@override_settings(TEMPLATES=TEMPLATES)
+class CustomTemplateEngineTests(TestCase):
+    """
+    Within django multiple template engines can be configured.
+    Some configurations will break the rest_framework used templates to render.
+    Usually the first template engine that finds a template by name will be used.
+    While using django_jinja2 and search extension configured to '*.html'
+    all the django common tags like `load` won't work anymore.
+    """
+
+    def setUp(self):
+        self.client = Client()
+
+    def test_TemplateSyntaxError(self):
+        with self.assertRaises(TemplateSyntaxError):
+            self.client.get('/')
+
+    def test_default_template_engine_setting(self):
+        # FIXME: when I set this in rest_framework/settings.py
+        # it's working...
+        # no idea how to properly change this setting for this testcase?
+        with override_settings(REST_FRAMEWORK={'DEFAULT_TEMPLATE_ENGINE': 'django'}):
+            self.client.get('/')