Handle partial bodies

lib/reverse_proxy/runner.ex

@@ -36,7 +36,30 @@ defmodule ReverseProxy.Runner do
     method = conn.method |> String.downcase |> String.to_atom
     url = "#{conn.scheme}://#{server}#{conn.request_path}?#{conn.query_string}"
     headers = conn.req_headers
-    {:ok, body, _conn} = Plug.Conn.read_body(conn)
+    body = case Plug.Conn.read_body(conn) do
+      {:ok, body, _conn} ->
+        body
+      {:more, body, conn} ->
+        {:stream,
+          Stream.resource(
+            fn -> {body, conn} end,
+            fn
+              {body, conn} ->
+                {[body], conn}
+              nil ->
+                {:halt, nil}
+              conn ->
+                case Plug.Conn.read_body(conn) do
+                  {:ok, body, _conn} ->
+                    {[body], nil}
+                  {:more, body, conn} ->
+                    {[body], conn}
+                end
+            end,
+            fn _ -> end
+          )
+        }
+    end
 
     {method, url, body, headers}
   end

test/fixtures/body_length.exs

@@ -0,0 +1,19 @@
+defmodule ReverseProxyTest.BodyLength do
+  def request(_method, _url, body, _headers, _opts \\ []) do
+    body_length = case body do
+      {:stream, body} ->
+        body
+        |> Enum.join("")
+        |> byte_size
+      body ->
+        body
+        |> byte_size
+    end
+
+    {:ok, %{
+      :headers => [],
+      :status_code => 200,
+      :body => "#{body_length}"
+    }}
+  end
+end

test/reverse_proxy/runner_test.exs

@@ -57,6 +57,18 @@ defmodule ReverseProxy.RunnerTest do
     assert conn.resp_body == "success"
   end
 
+  test "retrieve/3 - partial body" do
+    conn =
+      conn(:post, "/", String.duplicate("_", 8_000_000 + 1))
+      |> put_req_header("content-type", "application/json")
+      |> ReverseProxy.Runner.retreive(
+           ["localhost"],
+           ReverseProxyTest.BodyLength
+         )
+
+    assert conn.resp_body == "8000001"
+  end
+
   test "retreive/3 - http - success with response headers" do
     conn = conn(:get, "/")
     headers = ReverseProxyTest.SuccessHTTP.headers