added stop all spiders

lib/crawly/engine.ex

@@ -36,6 +36,20 @@ defmodule Crawly.Engine do
     GenServer.call(__MODULE__, {:stop_spider, spider_name})
   end
 
+  @spec stop_all_spiders() :: :ok
+  @doc "Stops all spiders, regardless of their current state. Runs :on_spider_closed_callback if available"
+  def stop_all_spiders() do
+    Crawly.Utils.list_spiders()
+    |> Enum.each(fn name ->
+      case Crawly.Utils.get_settings(:on_spider_closed_callback, name) do
+        nil -> :ignore
+        fun -> apply(fun, [:stop_all])
+      end
+
+      GenServer.call(__MODULE__, {:stop_spider, name})
+    end)
+  end
+
   @spec list_spiders() :: list_spiders()
   def list_spiders() do
     GenServer.call(__MODULE__, :list_spiders)

test/engine_test.exs

@@ -18,4 +18,20 @@ defmodule EngineTest do
     assert started_status.state == :started
     assert started_status.pid
   end
+
+  test "stop_all_spiders/0 stops all spiders" do
+    Crawly.Engine.list_spiders()
+    |> Enum.each(fn %{name: name} ->
+      Crawly.Engine.start_spider(name)
+    end)
+
+    Crawly.Engine.stop_all_spiders()
+
+    statuses = Crawly.Engine.list_spiders()
+
+    assert Enum.all?(statuses, fn status ->
+             assert status.state == :stopped
+             assert status.pid == nil
+           end)
+  end
 end