workaround fix for an issue in aiohttp.Client

sanic/exceptions.py

@@ -156,6 +156,8 @@ class MethodNotSupported(SanicException):
         super().__init__(message)
         self.headers = dict()
         self.headers["Allow"] = ", ".join(allowed_methods)
+        if method in ['HEAD', 'PATCH', 'PUT', 'DELETE']:
+            self.headers['Content-Length'] = 0
 
 
 @add_status_code(500)

sanic/testing.py

@@ -1,6 +1,8 @@
 import traceback
 from json import JSONDecodeError
 from sanic.log import logger
+from sanic.exceptions import MethodNotSupported
+from sanic.response import text
 
 
 HOST = '127.0.0.1'
@@ -54,6 +56,13 @@ class SanicTestClient:
                     results[0] = request
             self.app.request_middleware.appendleft(_collect_request)
 
+        @self.app.exception(MethodNotSupported)
+        async def error_handler(request, exception):
+            if request.method in ['HEAD', 'PATCH', 'PUT', 'DELETE']:
+                return text('', exception.status_code, headers=exception.headers)
+            else:
+                return self.app.error_handler.default(request, exception)
+
         @self.app.listener('after_server_start')
         async def _collect_response(sanic, loop):
             try: