Implement HasServer instead of using Raw

src/Yore/Servant.hs

@@ -0,0 +1,31 @@
+{-# LANGUAGE OverloadedRecordDot #-}
+{-# LANGUAGE TypeFamilies #-}
+
+module Yore.Servant (GetSendfile, Sendfile (..)) where
+
+import Network.HTTP.Types (ResponseHeaders, status200)
+import Network.Wai (responseFile)
+import Servant (HasServer (..))
+import Servant.Server.Internal.Delayed (runAction)
+import Servant.Server.Internal.RouteResult (RouteResult (..))
+import Servant.Server.Internal.Router (Router' (..))
+
+-- | Servant route type that responds with a file using @sendfile@.
+data GetSendfile
+
+data Sendfile = Sendfile
+  { headers :: ResponseHeaders
+  -- ^ The headers to send along with the file, e.g. @content-type@ or cache information.
+  , path :: FilePath
+  -- ^ The file to respond with.
+  }
+  deriving (Show)
+
+instance HasServer GetSendfile context where
+  type ServerT GetSendfile m = m Sendfile
+
+  hoistServerWithContext _ _ nt = nt
+
+  route _ _ action = RawRouter $ \env request respond ->
+    runAction action env request respond $ \sendfile ->
+      Route $ responseFile status200 sendfile.headers sendfile.path Nothing