Impl. config based dep. injection for ets;

- Check for extant url ids
- Various minor refactors

lib/url/repo/dets.ex

@@ -1,29 +0,0 @@
-defmodule Shortnr.URL.Repo.DETS do
-  @behaviour Shortnr.URL.Repo
-
-  @impl true
-  def get(key) do
-    case :dets.lookup(:urls, key) |> List.first() do
-      {_, url} -> {:ok, url}
-      nil -> {:ok, nil}
-    end
-  end
-
-  @impl true
-  def put(url) do
-    :ok = :dets.insert(:urls, {url.id, url})
-    :ok
-  end
-
-  @impl true
-  def list() do
-    resp = :dets.select(:urls, [{:"$1", [], [:"$1"]}])
-    {:ok, resp |> Enum.map(&elem(&1, 1))}
-  end
-
-  @impl true
-  def delete(key) do
-    :ok = :dets.delete(:urls, key)
-    :ok
-  end
-end

lib/url/repo/ets.ex

@@ -0,0 +1,36 @@
+defmodule Shortnr.URL.Repo.ETS do
+  @behaviour Shortnr.URL.Repo
+
+  @impl true
+  def get(key) do
+    case ets().lookup(:urls, key) |> List.first() do
+      {_, url} -> {:ok, url}
+      nil -> {:ok, nil}
+    end
+  end
+
+  @impl true
+  def put(url) do
+    :ok = ets().insert(:urls, {url.id, url})
+    :ok
+  end
+
+  @impl true
+  def list() do
+    resp = ets().select(:urls, [{:"$1", [], [:"$1"]}])
+    {:ok, resp |> Enum.map(&elem(&1, 1))}
+  end
+
+  @impl true
+  def delete(key) do
+    :ok = ets().delete(:urls, key)
+    :ok
+  end
+
+  @impl true
+  def reset do
+    :ok = ets().delete_all_objects(:urls)
+  end
+
+  defp ets, do: Application.fetch_env!(:shortnr, :ets_implementation)
+end

lib/url/repo/repo.ex

@@ -6,4 +6,5 @@ defmodule Shortnr.URL.Repo do
   @callback get(String.t()) :: {:ok, URL.t()} | Transport.error()
   @callback delete(String.t()) :: :ok | Transport.error()
   @callback list() :: {:ok, list(URL.t())} | Transport.error()
+  @callback reset() :: :ok | Transport.error()
 end

lib/url/url.ex

@@ -10,16 +10,23 @@ defmodule Shortnr.URL do
 
   @type t :: %__MODULE__{
           id: String.t(),
-          url: URI.t(),
           created_at: DateTime.t(),
-          updated_at: DateTime.t()
+          updated_at: DateTime.t(),
+          url: URI.t()
         }
 
   @spec create(String.t(), module()) :: {:ok, String.t()} | Transport.error()
   def create(url, repo) do
     url_struct = %URL{id: Util.gen_id(), url: URI.parse(url)}
-    :ok = repo.put(url_struct)
-    {:ok, url_struct.id}
+
+    {:ok, extant_url} = repo.get(url_struct.id)
+
+    if is_nil(extant_url) do
+      :ok = repo.put(url_struct)
+      {:ok, url_struct.id}
+    else
+      create(url, repo)
+    end
   end
 
   @spec get(String.t(), module()) :: {:ok, URL.t()} | Transport.error()