Implement child_spec/1 for DynamicSupervisor

Author: José Valim

lib/elixir/lib/dynamic_supervisor.ex

@@ -165,6 +165,15 @@ defmodule DynamicSupervisor do
     restarts: []
   ]
 
+  @doc false
+  def child_spec(arg) do
+    %{
+      id: DynamicSupervisor,
+      start: {DynamicSupervisor, :start_link, [arg]},
+      type: :supervisor
+    }
+  end
+
   @doc false
   defmacro __using__(opts) do
     quote location: :keep, bind_quoted: [opts: opts] do

lib/elixir/test/elixir/dynamic_supervisor_test.exs

@@ -9,6 +9,12 @@ defmodule DynamicSupervisorTest do
     def init(args), do: args
   end
 
+  test "can be supervised directly" do
+    children = [{DynamicSupervisor, strategy: :one_for_one, name: :dyn_sup_spec_test}]
+    assert {:ok, _} = Supervisor.start_link(children, strategy: :one_for_one)
+    assert DynamicSupervisor.which_children(:dyn_sup_spec_test) == []
+  end
+
   describe "use/2" do
     test "generates child_spec/1" do
       assert Simple.child_spec([:hello]) == %{