failing test case for static client

servant-client/src/Servant/Client.hs

@@ -2,7 +2,9 @@
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE FlexibleContexts       #-}
 {-# LANGUAGE FlexibleInstances      #-}
+{-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE InstanceSigs           #-}
+{-# LANGUAGE MultiParamTypeClasses  #-}
 {-# LANGUAGE OverloadedStrings      #-}
 {-# LANGUAGE PolyKinds              #-}
 {-# LANGUAGE ScopedTypeVariables    #-}
@@ -18,6 +20,7 @@ module Servant.Client
   ( AuthClientData
   , AuthenticateReq(..)
   , client
+  , staticClient
   , HasClient(..)
   , ClientM
   , mkAuthenticateReq
@@ -60,6 +63,36 @@ import           Servant.Common.Req
 client :: HasClient layout => Proxy layout -> Client layout
 client p = clientWithRoute p defReq
 
+
+class Foo layout where
+  type StaticClient layout :: *
+  staticClient :: Proxy layout -> BaseUrl -> StaticClient layout
+
+instance (Foo left, Foo right) => Foo (left :<|> right) where
+  type StaticClient (left :<|> right) = StaticClient left :<|> StaticClient right
+  staticClient p url =
+    staticClient pleft url :<|>
+    staticClient pright url
+    where pleft = Proxy :: Proxy left
+          pright = Proxy :: Proxy right
+
+instance OVERLAPPABLE_ (Client (combinator :> api) ~ Client api, Foo api) => Foo (combinator :> api) where
+  type StaticClient (combinator :> api) = StaticClient api
+  staticClient p url = staticClient (Proxy :: Proxy api) url
+
+instance OVERLAPPING_ (MimeRender ct a, Client (ReqBody (ct ': cts) a :> sublayout) ~ (a -> Client sublayout), Foo sublayout)
+      => Foo (ReqBody (ct ': cts) a :> sublayout) where
+  type StaticClient (ReqBody (ct ': cts) a :> sublayout) = a -> Client sublayout
+  staticClient p url = _
+
+instance (Client (Verb method status ctypes result) ~ (Manager -> BaseUrl -> ClientM result), ctypes ~ (c ': ct), MimeUnrender c result, ReflectMethod method) => Foo (Verb method status ctypes result) where
+  type StaticClient (Verb method status ctypes result) = Manager -> ClientM result
+  staticClient p url = \ mgr -> (client p) mgr url
+
+instance Foo Raw where
+  type StaticClient Raw = H.Method -> Manager -> ClientM (Int, ByteString, MediaType, [HTTP.Header], Response ByteString)
+  staticClient p url = \h m -> (client p) h m url
+
 -- | This class lets us define how each API combinator
 -- influences the creation of an HTTP request. It's mostly
 -- an internal class, you can just use 'client'.

servant-client/test/Servant/ClientSpec.hs

@@ -296,6 +296,11 @@ sucessSpec = beforeAll (startWaiApp server) $ afterAll endWaiApp $ do
             return $
               result === Right (cap, num, flag, body)
 
+    describe "staticClient" $ do
+      it "allows to pass in the BaseUrl to staticClient" $ \(_, baseUrl) -> do
+        let getGet' :: C.Manager -> ClientM Person
+            getGet' :<|> _ = staticClient api baseUrl
+        (left show <$> runExceptT (getGet' manager)) `shouldReturn` Right alice
 
 wrappedApiSpec :: Spec
 wrappedApiSpec = describe "error status codes" $ do