KeepRequest middleware #156

README.md

@@ -93,6 +93,7 @@ This is very similar to how [Plug Router](https://github.com/elixir-plug/plug#th
 - [`Tesla.Middleware.FollowRedirects`](https://hexdocs.pm/tesla/Tesla.Middleware.FollowRedirects.html) - follow 3xx redirects
 - [`Tesla.Middleware.MethodOverride`](https://hexdocs.pm/tesla/Tesla.Middleware.MethodOverride.html) - set X-Http-Method-Override
 - [`Tesla.Middleware.Logger`](https://hexdocs.pm/tesla/Tesla.Middleware.Logger.html) - log requests (method, url, status, time)
+- [`Tesla.Middleware.KeepRequest`](https://hexdocs.pm/tesla/Tesla.Middleware.KeepRequest.html) - keep request body & headers
 
 #### Formats
 - [`Tesla.Middleware.FormUrlencoded`](https://hexdocs.pm/tesla/Tesla.Middleware.FormUrlencoded.html) - urlencode POST body parameter, useful for POSTing a map/keyword list

lib/tesla/middleware/keep_request.ex

@@ -0,0 +1,26 @@
+defmodule Tesla.Middleware.KeepRequest do
+  @behaviour Tesla.Middleware
+
+  @moduledoc """
+  Store request body & headers into opts.
+
+  ### Example
+  ```
+  defmodule MyClient do
+    use Tesla
+
+    plug Tesla.Middleware.KeepRequest
+  end
+
+  {:ok, env} = MyClient.post("/", "request-data")
+  env.body # => "response-data"
+  env.opts[:req_body] # => "request-data"
+  ```
+  """
+  def call(env, next, _opts) do
+    env
+    |> Tesla.put_opt(:req_body, env.body)
+    |> Tesla.put_opt(:req_headers, env.headers)
+    |> Tesla.run(next)
+  end
+end

test/tesla/middleware/keep_request_test.exs

@@ -0,0 +1,12 @@
+defmodule Tesla.Middleware.KeepRequestTest do
+  use ExUnit.Case
+
+  @middleware Tesla.Middleware.KeepRequest
+
+  test "put request body & headers into opts" do
+    env = %Tesla.Env{body: "reqbody", headers: [{"x-request", "header"}]}
+    assert {:ok, env} = @middleware.call(env, [], [])
+    assert env.opts[:req_body] == "reqbody"
+    assert env.opts[:req_headers] == [{"x-request", "header"}]
+  end
+end