Support async view methods in extend_schema_view.

Author: tbeadle

drf_spectacular/drainage.py

@@ -182,8 +182,12 @@ def get_view_method_names(view, schema=None) -> List[str]:
     return [
         item for item in dir(view) if callable(getattr(view, item)) and (
             item in view.http_method_names
-            or item in schema.method_mapping.values()
-            or item == 'list'
+            or (
+                item in schema.async_method_mapping.values()
+                if view.view_is_async
+                else item in schema.method_mapping.values()
+            )
+            or item == ('alist' if view.view_is_async else 'list')
             or hasattr(getattr(view, item), 'mapping')
         )
     ]
@@ -202,9 +206,14 @@ def isolate_view_method(view, method_name):
     if method_name in view.__dict__ and method.__name__ != 'handler':
         return method
 
-    @functools.wraps(method)
-    def wrapped_method(self, request, *args, **kwargs):
-        return method(self, request, *args, **kwargs)
+    if getattr(view, "view_is_async", False):
+        @functools.wraps(method)
+        async def wrapped_method(self, request, *args, **kwargs):
+            return await method(self, request, *args, **kwargs)
+    else:
+        @functools.wraps(method)
+        def wrapped_method(self, request, *args, **kwargs):
+            return method(self, request, *args, **kwargs)
 
     # wraps() will only create a shallow copy of method.__dict__. Updates to "kwargs"
     # via @extend_schema would leak to the original method. Isolate by creating a copy.

drf_spectacular/openapi.py

@@ -57,6 +57,13 @@ class AutoSchema(ViewInspector):
         'patch': 'partial_update',
         'delete': 'destroy',
     }
+    async_method_mapping = {
+        'get': 'aretrieve',
+        'post': 'acreate',
+        'put': 'aupdate',
+        'patch': 'partial_aupdate',
+        'delete': 'adestroy',
+    }
 
     def get_operation(
             self,