Expose Http.Encoder constructor

Author: rizo

src/helix/Helix.mli

@@ -141,6 +141,7 @@ module Http : sig
   module Encoder : sig
     type 'a t
 
+    val make : ?content_type:string -> ('a -> Stdweb.Fetch.Body.t) -> 'a t
     val empty : unit t
     val text : string t
     val form_data : Stdweb.Form_data.t t

src/helix/Http.ml

@@ -20,6 +20,8 @@ type body = Stdweb.Fetch.Body.t
 module Encoder = struct
   type 'a t = string option * ('a -> Fetch.Body.t)
 
+  let make ?(content_type) f = content_type, f
+
   let to_undefined_body _ = Fetch.Body.unsafe_of_js Jx.undefined
   let empty = (None, to_undefined_body)
   let ignore = (None, to_undefined_body)