Issue http 405 for anything but POST on RPC

Fixes #481

src/PostgREST/ApiRequest.hs

@@ -31,6 +31,7 @@ data Action = ActionCreate | ActionRead
             | ActionUnknown BS.ByteString deriving Eq
 -- | The target db object of a user action
 data Target = TargetIdent QualifiedIdentifier
+            | TargetProc  QualifiedIdentifier
             | TargetRoot
             | TargetUnknown [T.Text]
 -- | How to return the inserted data
@@ -90,7 +91,7 @@ userApiRequest schema req reqBody =
                  []            -> TargetRoot
                  [table]       -> TargetIdent
                                   $ QualifiedIdentifier schema table
-                 ["rpc", proc] -> TargetIdent
+                 ["rpc", proc] -> TargetProc
                                   $ QualifiedIdentifier schema proc
                  other         -> TargetUnknown other
       payload = case pickContentType (lookupHeader "content-type") of

src/PostgREST/App.hs

@@ -155,7 +155,7 @@ app dbStructure conf reqBody req =
           filterCol _ _ _ =  False
       return $ responseLBS status200 [jsonH, allOrigins] $ cs body
 
-    (ActionInvoke, TargetIdent qi,
+    (ActionInvoke, TargetProc qi,
      Just (PayloadJSON (UniformObjects payload))) -> do
       exists <- H.query qi doesProcExist
       if exists
@@ -178,6 +178,8 @@ app dbStructure conf reqBody req =
 
     (ActionUnknown _, _, _) -> return notFound
 
+    (_, TargetProc _, _) -> return $ responseLBS status405 [] ""
+
     (_, TargetUnknown _, _) -> return notFound
 
     (_, _, Just (PayloadParseError e)) ->