add logger middleware

lib/maxwell/middleware/json.ex

@@ -13,7 +13,7 @@ defmodule Maxwell.Middleware.Json do
   @middleware Maxwell.Middleware.Json
   # or
   @middleware Maxwell.Middleware.Json, [encode_content_type: "application/json", encode_func: &other_json_lib.encode/1,
-                                        decode_content_types: ["yourowntype"],   decode_func: &other_json_lib.encode/1]
+  decode_content_types: ["yourowntype"],   decode_func: &other_json_lib.encode/1]
   ```
   """
   use Maxwell.Middleware
@@ -28,7 +28,7 @@ defmodule Maxwell.Middleware.Json do
 end
 
 defmodule Maxwell.Middleware.EncodeJson do
-@moduledoc  """
+  @moduledoc  """
   Encode request's body to json when request's body is not nil
 
   It will auto add `%{'Content-Type': 'application/json'}` to request's headers
@@ -42,7 +42,7 @@ defmodule Maxwell.Middleware.EncodeJson do
   @middleware Maxwell.Middleware.EncodeJson, [encode_content_type: "application/json", encode_func: &other_json_lib.encode/1]
   ```
   """
-use Maxwell.Middleware
+  use Maxwell.Middleware
 
   def request(env, opts) do
     encode_fun = opts[:encode_func] || &Poison.encode/1
@@ -63,12 +63,12 @@ use Maxwell.Middleware
 end
 
 defmodule Maxwell.Middleware.DecodeJson do
-@moduledoc  """
+  @moduledoc  """
   Decode reponse's body to json when
 
-    1. Reponse header contain `{'Content-Type', "application/json"}` and body is binary
+  1. Reponse header contain `{'Content-Type', "application/json"}` and body is binary
 
-    2. Reponse is list
+  2. Reponse is list
 
   Default json_lib is Poison
   ```ex
@@ -79,7 +79,7 @@ defmodule Maxwell.Middleware.DecodeJson do
   @middleware Maxwell.Middleware.DecodeJson, [decode_content_types: ["text/javascript"], decode_func: &other_json_lib.decode/1]
   ```
   """
-use Maxwell.Middleware
+  use Maxwell.Middleware
 
   def response(response, opts) do
     decode_fun = opts[:decode_func] || &Poison.decode/1
@@ -98,7 +98,7 @@ use Maxwell.Middleware
           end
         _ ->
           {:ok, result}
-        end
+      end
     end
 
   end

lib/maxwell/middleware/log.ex

@@ -0,0 +1,59 @@
+defmodule Maxwell.Middleware.Logger do
+  @moduledoc  """
+  Log the request
+  Log the response
+  ```ex
+  # Client.ex
+  use Maxwell.Builder ~(get)a
+  @middleware Maxwell.Middleware.Log
+
+  def request do
+  "/test" |> url |> get!
+  end
+  ```
+  """
+  use Maxwell.Middleware
+  require Logger
+
+  def request(env, opts) do
+    "REQUEST: "
+    |> Kernel.<>(format_message(env))
+    |> Logger.info
+    env
+  end
+  def response(result, log_fun) do
+    case result do
+      {:error, reason} ->
+        format_reason = :io_lib.format("~p", [reason])
+        Logger.error("RESPONSE ERROR: " <> format_reason)
+      {:ok, env} ->
+        message = "RESPONSE: " <> format_message(env)
+        cond do
+          env.status >= 400 -> Logger.error message
+          env.status >= 300 -> Logger.warn message
+          true              -> Logger.info message
+        end
+    end
+    result
+  end
+
+  defp format_message(env) do
+    method = env.method |> to_string |> String.upcase
+    status = case env.status do
+               nil -> "";
+               200 -> "#{IO.ANSI.green} => 200"
+               status1 -> " => #{status1}"
+             end
+    header = case Map.equal?(env.headers, %{}) do
+               true -> ""
+               false -> :io_lib.format("~p", [env.headers])
+             end
+    options = case env.opts do
+                [] -> ""
+                options -> :io_lib.format("~p", [options])
+              end
+    "#{method} #{env.url} #{header} #{options} #{status}"
+  end
+
+end
+

test/maxwell/middleware/json_test.exs

@@ -5,6 +5,7 @@ defmodule JsonTest do
     use Maxwell.Builder
 
     middleware Maxwell.Middleware.Json, [encode_func: &Poison.encode/1, decode_fun: &Poison.decode/1, decode_content_types: ["text/html"], encode_content_type: "application/json"]
+    middleware Maxwell.Middleware.Logger
 
     adapter fn (env) ->
       case env.url do

test/maxwell/middleware/logger_test.exs

@@ -0,0 +1,16 @@
+defmodule LoggerTest do
+  use ExUnit.Case
+  import Maxwell.TestHelper
+
+  test "Middleware.Logger request" do
+    env = request(Maxwell.Middleware.Logger, %Maxwell{url: "/path"}, [])
+    assert env == %Maxwell{url: "/path"}
+  end
+
+  test "Middleware.Logger response" do
+    {:ok, env} = response(Maxwell.Middleware.Logger, {:ok, %Maxwell{url: "/path"}}, [])
+    assert env == %Maxwell{url: "/path"}
+  end
+
+end
+