Make Horde.Supervisor child_spec overridable

Fixes #107

lib/horde/supervisor.ex

@@ -45,23 +45,27 @@ defmodule Horde.Supervisor do
   Then you can use `MySupervisor.child_spec/1` and `MySupervisor.start_link/1` in the same way as you'd use `Horde.Supervisor.child_spec/1` and `Horde.Supervisor.start_link/1`.
   """
 
-  defmacro __using__(_opts) do
+  defmacro __using__(opts) do
     quote do
       @behaviour Horde.Supervisor
 
       def child_spec(options) do
         options = Keyword.put_new(options, :id, __MODULE__)
 
-        %{
+        default = %{
           id: Keyword.get(options, :id, __MODULE__),
           start: {__MODULE__, :start_link, [options]},
           type: :supervisor
         }
+
+        Supervisor.child_spec(default, unquote(Macro.escape(opts)))
       end
 
       def start_link(options) do
         Horde.Supervisor.start_link(Keyword.put(options, :init_module, __MODULE__))
       end
+
+      defoverridable child_spec: 1
     end
   end
 

test/supervisor_test.exs

@@ -89,6 +89,28 @@ defmodule SupervisorTest do
       {:ok, members} = Horde.Cluster.members(:init_sup_test_1)
       assert 2 = Enum.count(members)
     end
+
+    test "can use `child_spec` function to override defaults from Horde.Supervisor" do
+      spec = %{
+        id: 123,
+        start:
+          {TestSupervisor3, :start_link,
+           [
+             custom_id: 123,
+             name: :init_sup_test_3,
+             strategy: :one_for_one
+           ]},
+        restart: :transient,
+        type: :supervisor
+      }
+
+      assert spec =
+               TestSupervisor3.child_spec(
+                 custom_id: 123,
+                 name: :init_sup_test_3,
+                 strategy: :one_for_one
+               )
+    end
   end
 
   describe ".start_child/2" do

test/support/module_based_supervisor.ex

@@ -13,3 +13,20 @@ defmodule TestSupervisor2 do
     {:ok, Keyword.put(options, :members, [:init_sup_test_1, :init_sup_test_2])}
   end
 end
+
+defmodule TestSupervisor3 do
+  use Horde.Supervisor
+
+  def init(options) do
+    {:ok, Keyword.put(options, :members, [:init_sup_test_3, :init_sup_test_3])}
+  end
+
+  def child_spec(args) do
+    %{
+      id: args[:custom_id],
+      start: {__MODULE__, :start_link, [args]},
+      restart: :transient,
+      type: :supervisor
+    }
+  end
+end