major refactor

config/config.exs

@@ -1,7 +1,8 @@
 use Mix.Config
 
 config :sugar,
-  router: HexDepsChecker.Router
+  router: HexDepsChecker.Router,
+  show_debugger: true
 
 config :sugar, HexDepsChecker.Router,
   https_only: false,

lib/hex_deps_checker/badge.ex

@@ -0,0 +1,30 @@
+defmodule HexDepsChecker.Badge do
+  @badge_base "https://img.shields.io/badge/"
+
+  def url(code) do
+    @badge_base <> name(code) <> ".svg"
+  end
+
+  defp name(code) do
+    status = statuses[code]
+    msg = status.msg
+      |> String.replace("_", "__")
+      |> String.replace("-", "--")
+      |> String.replace(" ", "_")
+    ["dependencies",
+     msg,
+     status.color]
+      |> Enum.join("-")
+  end
+
+  defp statuses do
+    [
+      ok:        %{color: "green",
+                   msg:   "up to date"},
+      available: %{color: "yellow",
+                   msg:   "update(s) available"},
+      unknown:   %{color: "lightgrey",
+                   msg:   "unknown"}
+    ]
+  end
+end

lib/hex_deps_checker/controllers/api.ex

@@ -0,0 +1,38 @@
+defmodule HexDepsChecker.Controllers.Api do
+  use Sugar.Controller
+  use HexDepsChecker.ErrorHandler
+
+  defmodule UnknownSCMHostError do
+    defexception message: "Unknown SCM host"
+  end
+
+  def lock(conn, loc: loc, org: org, repo: repo) do
+    url = get_url(loc, org, repo)
+    r = url |> HTTPoison.get!
+    eval_opts = [requires: [],
+                 macros: [],
+                 aliases: [],
+                 functions: []]
+    json = r.body
+      |> Code.eval_string([], eval_opts)
+      |> elem(0)
+      |> Enum.map(fn {dep, {:hex, dep, version}} ->
+        %{} |> Map.put(dep, Hex.has_update?(dep, version))
+      end)
+      |> Poison.encode!
+    raw conn |> resp(200, json)
+  end
+
+  defp get_url(loc, org, repo) do
+    case loc do
+      "github"    -> "https://raw.githubusercontent.com/#{org}/#{repo}/master/mix.lock"
+      "bitbucket" -> "https://bitbucket.org/#{org}/#{repo}/raw/master/mix.lock"
+      _           -> raise UnknownSCMHostError
+    end
+  end
+
+  defp handle_errors(conn, assigns) do
+    json conn, %{error: assigns.reason}
+  end
+end
+

lib/hex_deps_checker/controllers/main.ex

@@ -1,90 +1,12 @@
 defmodule HexDepsChecker.Controllers.Main do
   use Sugar.Controller
+  alias HexDepsChecker.Badge
 
-  defmodule UnknownHostError do
-    defexception message: "Unknown SCM host"
-  end
-
-  @badge_base "https://img.shields.io/badge/"
-  @headers [{"User-Agent", "HexDepsChecker (0.0.1) - slogsdon"}]
-
-  def index(conn, []) do
-    conn
-      |> send_resp(200, "Hello World")
-  end
-
-  def lock(conn, loc: loc, org: org, repo: repo) do
-    url = case loc do
-        "github"    -> "https://raw.githubusercontent.com/#{org}/#{repo}/master/mix.lock"
-        "bitbucket" -> "https://bitbucket.org/#{org}/#{repo}/raw/master/mix.lock"
-        _           -> raise UnknownHostError
-    end
-
-    r = url |> HTTPoison.get!
-    eval_opts = [requires: [],
-                 macros: [],
-                 aliases: [],
-                 functions: []]
-    json = r.body
-      |> Code.eval_string([], eval_opts)
-      |> elem(0)
-      |> Enum.map(fn {dep, {:hex, dep, version}} ->
-        %{} |> Map.put(dep, has_update?(dep, version))
-      end)
-      |> Poison.encode!
-    raw conn |> resp(200, json)
+  def index(conn, _) do
+    static conn, "index.html"
   end
 
   def image(conn, _args) do
-    name = get_name(:ok)
-    conn
-      |> put_resp_header("Location", @badge_base <> "#{name}.svg")
-      |> send_resp(302, "Found")
-  end
-
-  def get_name(code) do
-    status = statuses[code]
-    msg = status.msg
-      |> String.replace("_", "__")
-      |> String.replace("-", "--")
-      |> String.replace(" ", "_")
-    ["dependencies",
-     msg,
-     status.color]
-      |> Enum.join("-")
-  end
-
-  def has_update?(dep, version) do
-    latest = HTTPoison.get!("https://hex.pm/api/packages/#{dep}", @headers)
-      |> Map.get(:body)
-      |> Poison.decode!
-      |> Map.get("releases")
-      |> hd
-
-    Version.compare(latest["version"], version) == :gt
-  end
-
-  def get_raw(package) do
-    HTTPoison.get!("https://hex.pm/api/packages/#{package}", @headers)
-      |> Map.get(:body)
-      |> Poison.decode!
-      |> Map.get("releases")
-      |> hd
-      |> Map.get("url")
-      |> HTTPoison.get!
-      |> Map.get(:body)
-      |> Poison.decode!
-      |> Map.get("requirements")
-  end
-
-  defp statuses do
-    [
-      ok:        %{color: "green",
-                   msg:   "up to date"},
-      available: %{color: "yellow",
-                   msg:   "update(s) available"},
-      unknown:   %{color: "lightgrey",
-                   msg:   "unknown"}
-    ]
+    redirect conn, Badge.url(:ok)
   end
 end

lib/hex_deps_checker/error_handler.ex

@@ -0,0 +1,51 @@
+defmodule HexDepsChecker.ErrorHandler do
+  @doc false
+  defmacro __using__(_) do
+    quote location: :keep do
+      @before_compile unquote(__MODULE__)
+
+      defp handle_errors(conn, assigns) do
+        Plug.Conn.send_resp(conn, conn.status, "Something went wrong")
+      end
+
+      defoverridable [handle_errors: 2]
+    end
+  end
+
+  @doc false
+  defmacro __before_compile__(_env) do
+    quote location: :keep do
+      def call(conn, opts) do
+        try do
+          super(conn, opts)
+        catch
+          kind, reason ->
+            unquote(__MODULE__).__catch__(conn, kind, reason, System.stacktrace, &handle_errors/2)
+        end
+      end
+    end
+  end
+
+  @already_sent {:plug_conn, :sent}
+
+  @doc false
+  def __catch__(conn, kind, reason, stack, handle_errors) do
+    receive do
+      @already_sent ->
+        send self(), @already_sent
+    after
+      0 ->
+        reason = Exception.normalize(kind, reason, stack)
+
+        conn
+        |> Plug.Conn.put_status(status(kind, reason))
+        |> handle_errors.(%{kind: kind, reason: reason, stack: stack})
+    end
+
+    :erlang.raise(kind, reason, stack)
+  end
+
+  defp status(:error, error),  do: Plug.Exception.status(error)
+  defp status(:throw, _throw), do: 500
+  defp status(:exit, _exit),   do: 500
+end

lib/hex_deps_checker/hex.ex

@@ -0,0 +1,26 @@
+defmodule HexDepsChecker.Hex do
+  @headers [{"User-Agent", "HexDepsChecker (0.0.1) - slogsdon"}]
+
+  def has_update?(dep, version) do
+    latest = HTTPoison.get!("https://hex.pm/api/packages/#{dep}", @headers)
+      |> Map.get(:body)
+      |> Poison.decode!
+      |> Map.get("releases")
+      |> hd
+
+    Version.compare(latest["version"], version) == :gt
+  end
+
+  def get_raw(package) do
+    HTTPoison.get!("https://hex.pm/api/packages/#{package}", @headers)
+      |> Map.get(:body)
+      |> Poison.decode!
+      |> Map.get("releases")
+      |> hd
+      |> Map.get("url")
+      |> HTTPoison.get!
+      |> Map.get(:body)
+      |> Poison.decode!
+      |> Map.get("requirements")
+  end
+end

lib/hex_deps_checker/router.ex

@@ -1,18 +1,15 @@
 defmodule HexDepsChecker.Router do
   use Sugar.Router
-  plug Sugar.Plugs.HotCodeReload
+  use HexDepsChecker.ErrorHandler
+  alias HexDepsChecker.Controllers.Main
+  alias HexDepsChecker.Controllers.Api
 
-  if Sugar.Config.get(:sugar, :show_debugger, false) do
-    plug Plug.Debugger, otp_app: :hex_deps_checker
-  end
+  plug Plug.Static, at: "/", from: :hex_deps_checker
 
-  plug Plug.Static, at: "/static", from: :hex_deps_checker
+  # Main routes
+  get "/",      Main, :index
+  get "/image", Main, :image
 
-  # Uncomment the following line for session store
-  # plug Plug.Session, store: :ets, key: "sid", secure: true, table: :session
-
-  # Define your routes here
-  get "/", HexDepsChecker.Controllers.Main, :index
-  get "/image", HexDepsChecker.Controller.Main, :image
-  get "/:loc/:org/:repo", HexDepsChecker.Controllers.Main, :lock
+  # Api routes
+  get "/api/:loc/:org/:repo", Api, :lock
 end

lib/hex_deps_checker/views/main/index.html.eex → priv/static/index.html

@@ -1,7 +1,7 @@
 <!doctype html>
 <html lang="en-US">
 <head>
-  <title>main/index - HexDepsChecker</title>
+  <title>HexDepsChecker</title>
 </head>
 <body>
   Hello World