Bootstrap the /api namespace

lib/music_library_web/controllers/collection_controller.ex

@@ -0,0 +1,11 @@
+defmodule MusicLibraryWeb.CollectionController do
+  use MusicLibraryWeb, :controller
+
+  alias MusicLibrary.Collection
+
+  def latest(conn, _params) do
+    latest_record = Collection.get_latest_record!()
+
+    render(conn, :show, record: latest_record)
+  end
+end

lib/music_library_web/controllers/collection_json.ex

@@ -0,0 +1,5 @@
+defmodule MusicLibraryWeb.CollectionJSON do
+  def show(%{record: record}) do
+    Map.take(record, [:title])
+  end
+end

lib/music_library_web/router.ex

@@ -50,6 +50,12 @@ defmodule MusicLibraryWeb.Router do
     end
   end
 
+  scope "/api", MusicLibraryWeb do
+    pipe_through :api
+
+    get "/collection/latest", CollectionController, :latest
+  end
+
   # Other scopes may use custom stacks.
   # scope "/api", MusicLibraryWeb do
   #   pipe_through :api

test/music_library_web/controllers/collection_controller_test.exs

@@ -0,0 +1,18 @@
+defmodule MusicLibraryWeb.CollectionControllerTest do
+  use MusicLibraryWeb.ConnCase
+
+  import MusicLibrary.RecordsFixtures
+
+  defp create_record(_) do
+    %{record: record_fixture()}
+  end
+
+  describe "GET /api/collection/latest" do
+    setup [:create_record]
+
+    test "it returns the latest record", %{conn: conn, record: record} do
+      conn = get(conn, ~p"/api/collection/latest")
+      assert json_response(conn, 200) == %{"title" => record.title}
+    end
+  end
+end