add Tesla.put_opt(key,value) helper function

Author: teamon

lib/tesla.ex

@@ -340,6 +340,12 @@ defmodule Tesla do
   def run(env, [{m,f} | rest]),     do: apply(m, f, [env, rest])
   def run(env, [{m,f,a} | rest]),   do: apply(m, f, [env, rest | a])
 
+  # useful helper fuctions
+  def put_opt(env, key, value) do
+    Map.update!(env, :opts, &Keyword.put(&1, key, value))
+  end
+
+
   def default_adapter do
     adapter = Application.get_env(:tesla, :adapter, :httpc) |> Tesla.alias
     {adapter, []}

lib/tesla/middleware/core.ex

@@ -96,7 +96,7 @@ defmodule Tesla.Middleware.DecodeRels do
 
   def parse_rels(env) do
     if link = env.headers["link"] do
-      Map.update!(env, :opts, &Keyword.put(&1, :rels, rels(link)))
+      Tesla.put_opt(env, :rels, rels(link))
     else
       env
     end