Convert from the retired ExFSWatch to FileSystem

Initial working commit. Use the new GenServer only API.

lib/elixir_koans.ex

@@ -8,7 +8,7 @@ defmodule ElixirKoans do
       worker(Display, []),
       worker(Tracker, []),
       worker(Runner, []),
-      worker(Watcher, [])
+      worker(Watcher, [[]])
     ]
 
     opts = [strategy: :one_for_one, name: ElixirKoans.Supervisor]

lib/watcher.ex

@@ -1,14 +1,21 @@
 defmodule Watcher do
-  use ExFSWatch, dirs: ["lib/koans"]
+  use GenServer
 
-  def start_link do
-    start()
+  def start_link(args) do
+    GenServer.start_link(__MODULE__, args)
   end
 
-  def callback(file, events)  do
+  def init(args) do
+    {:ok, watcher_pid} = FileSystem.start_link(dirs: ["lib/koans"])
+    FileSystem.subscribe(watcher_pid)
+    {:ok, %{watcher_pid: watcher_pid}}
+  end
+
+  def handle_info({:file_event, watcher_pid, {path, events}}, %{watcher_pid: watcher_pid}=state) do
     if Enum.member?(events, :modified) do
-      file |> normalize |> reload
+      path |> normalize |> reload
     end
+    {:noreply, state}
   end
 
   defp reload(file) do

mix.exs

@@ -11,11 +11,11 @@ defmodule Koans.Mixfile do
 
   def application do
     [mod: {ElixirKoans, []},
-     applications: [:exfswatch, :logger]]
+     applications: [:file_system, :logger]]
   end
 
   defp deps do
-    [{:exfswatch, "~> 0.3"}]
+    [{:file_system, "~> 0.2"}]
   end
 
   defp elixirc_path(:test), do: ["lib/", "test/support"]

mix.lock

@@ -1,2 +1 @@
-%{"exfswatch": {:hex, :exfswatch, "0.4.1", "008db817f6096eec69d17c7ca562c572fb4409728a09f465dea7e31190fb983c", [:mix], []},
-  "fs": {:hex, :fs, "2.12.0", "ad631efacc9a5683c8eaa1b274e24fa64a1b8eb30747e9595b93bec7e492e25e", [:rebar3], []}}
+%{"file_system": {:hex, :file_system, "0.2.2", "7f1e9de4746f4eb8a4ca8f2fbab582d84a4e40fa394cce7bfcb068b988625b06", [], [], "hexpm"}}