From 79ce07ba9b0d46cb7c0c592ef47e7f834f651df4 Mon Sep 17 00:00:00 2001
From: enrico <enrico.massa@heveaconnect.com>
Date: Fri, 19 Aug 2022 17:03:22 +0800
Subject: [PATCH] Tentative async implementation

---
 rest_framework/views.py |  7 +++-
 tests/test_views.py     | 79 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 81 insertions(+), 5 deletions(-)

diff --git a/rest_framework/views.py b/rest_framework/views.py
index 5b0622069..a90b4d3c0 100644
--- a/rest_framework/views.py
+++ b/rest_framework/views.py
@@ -1,6 +1,8 @@
 """
 Provides an APIView class that is the base of all views in REST framework.
 """
+import asyncio
+from asgiref.sync import async_to_sync
 from django.conf import settings
 from django.core.exceptions import PermissionDenied
 from django.db import connections, models
@@ -503,7 +505,10 @@ class APIView(View):
             else:
                 handler = self.http_method_not_allowed
 
-            response = handler(request, *args, **kwargs)
+            if asyncio.iscoroutinefunction(handler):
+                response = async_to_sync(handler)(request, *args, **kwargs)
+            else:
+                response = handler(request, *args, **kwargs)
 
         except Exception as exc:
             response = self.handle_exception(exc)
diff --git a/tests/test_views.py b/tests/test_views.py
index 2648c9fb3..da6271d2c 100644
--- a/tests/test_views.py
+++ b/tests/test_views.py
@@ -22,16 +22,24 @@ class BasicView(APIView):
         return Response({'method': 'POST', 'data': request.data})
 
 
+class BasicAsyncView(APIView):
+    async def get(self, request, *args, **kwargs):
+        return Response({'method': 'GET'})
+
+    async def post(self, request, *args, **kwargs):
+        return Response({'method': 'POST', 'data': request.data})
+
+
 @api_view(['GET', 'POST', 'PUT', 'PATCH'])
 def basic_view(request):
     if request.method == 'GET':
-        return {'method': 'GET'}
+        return Response({'method': 'GET'})
     elif request.method == 'POST':
-        return {'method': 'POST', 'data': request.data}
+        return Response({'method': 'POST', 'data': request.data})
     elif request.method == 'PUT':
-        return {'method': 'PUT', 'data': request.data}
+        return Response({'method': 'PUT', 'data': request.data})
     elif request.method == 'PATCH':
-        return {'method': 'PATCH', 'data': request.data}
+        return Response({'method': 'PATCH', 'data': request.data})
 
 
 class ErrorView(APIView):
@@ -72,6 +80,23 @@ class ClassBasedViewIntegrationTests(TestCase):
     def setUp(self):
         self.view = BasicView.as_view()
 
+    def test_get_succeeds(self):
+        request = factory.get('/', content_type='application/json')
+        response = self.view(request)
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data == {'method': 'GET'}
+
+    # def test_post_succeeds(self):
+    #     request = factory.post('/', {"test": "foo"}, content_type='application/json')
+    #     response = self.view(request)
+    #     import pdb; pdb.set_trace()
+    #     expected = {
+    #         'method': 'POST',
+    #         'data': {'test': 'foo'}
+    #     }
+    #     assert response.status_code == status.HTTP_200_OK
+    #     assert response.data == expected
+
     def test_400_parse_error(self):
         request = factory.post('/', 'f00bar', content_type='application/json')
         response = self.view(request)
@@ -86,6 +111,52 @@ class FunctionBasedViewIntegrationTests(TestCase):
     def setUp(self):
         self.view = basic_view
 
+    def test_get_succeeds(self):
+        request = factory.get('/', content_type='application/json')
+        response = self.view(request)
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data == {'method': 'GET'}
+
+    # def test_post_succeeds(self):
+    #     request = factory.post('/', {'test': 'foo'}, content_type='application/json')
+    #     response = self.view(request)
+    #     expected = {
+    #         'method': 'POST',
+    #         'data': {'test': 'foo'}
+    #     }
+    #     assert response.status_code == status.HTTP_200_OK
+    #     assert response.data == expected
+
+    def test_400_parse_error(self):
+        request = factory.post('/', 'f00bar', content_type='application/json')
+        response = self.view(request)
+        expected = {
+            'detail': JSON_ERROR
+        }
+        assert response.status_code == status.HTTP_400_BAD_REQUEST
+        assert sanitise_json_error(response.data) == expected
+
+
+class ClassBasedAsyncViewIntegrationTests(TestCase):
+    def setUp(self):
+        self.view = BasicAsyncView.as_view()
+
+    def test_get_succeeds(self):
+        request = factory.get('/', content_type='application/json')
+        response = self.view(request)
+        assert response.status_code == status.HTTP_200_OK
+        assert response.data == {'method': 'GET'}
+
+#     def test_post_succeeds(self):
+#         request = factory.post('/', {'test': 'foo'}, content_type='application/json')
+#         response = self.view(request)
+#         expected = {
+#             'method': 'POST',
+#             'data': {'test': 'foo'}
+#         }
+#         assert response.status_code == status.HTTP_200_OK
+#         assert response.data == expected
+
     def test_400_parse_error(self):
         request = factory.post('/', 'f00bar', content_type='application/json')
         response = self.view(request)