Simplify get/1 return

lib/nabo/post.ex

@@ -59,7 +59,9 @@ defmodule Nabo.Post do
     :reading_time
   ]
 
-  @type t :: %__MODULE__{
+  @type slug() :: String.t()
+
+  @type t() :: %__MODULE__{
     body: String.t,
     body_html: String.t,
     datetime: DateTime.t,
@@ -68,7 +70,7 @@ defmodule Nabo.Post do
     excerpt: String.t,
     excerpt_html: String.t,
     metadata: Map.t,
-    slug: String.t,
+    slug: slug(),
     title: String.t,
   }
 

lib/nabo/repo.ex

@@ -83,21 +83,19 @@ defmodule Nabo.Repo do
 
       for %{slug: slug} = post <- @posts do
         def get(unquote(slug)) do
-          {:ok, unquote(Macro.escape(post))}
+          unquote(Macro.escape(post))
         end
       end
 
-      def get(slug) do
-        {:error, "cannot find post #{slug}, availables: #{inspect(availables())}"}
-      end
+      def get(slug), do: nil
 
-      def get!(name) when is_binary(name) do
-        case get(name) do
-          {:ok, post} ->
-            post
+      def get!(slug) when is_binary(slug) do
+        case get(slug) do
+          nil ->
+            raise "could not find post with #{inspect(slug)}, availables: #{inspect(availables())}"
 
-          {:error, reason} ->
-            raise(reason)
+          post ->
+            post
         end
       end
 
@@ -144,20 +142,20 @@ defmodule Nabo.Repo do
 
   ## Example
 
-      {:ok, post} = MyRepo.get("my-slug")
+      MyRepo.get("my-slug")
 
   """
-  @callback get(name :: String.t()) :: {:ok, Nabo.Post.t()} | {:error, any}
+  @callback get(slug :: Nabo.Post.slug()) :: Nabo.Post.t() | nil
 
   @doc """
-  Similar to `get/1` but raises error when no post was found.
+  Similar to `get/1` but raises error when no post is found.
 
   ## Example
 
       post = MyRepo.get!("my-slug")
 
   """
-  @callback get!(name :: String.t()) :: Nabo.Post.t()
+  @callback get!(slug :: Nabo.Post.slug()) :: Nabo.Post.t()
 
   @doc """
   Fetches all available posts in the repo.
@@ -209,5 +207,5 @@ defmodule Nabo.Repo do
       availables = MyRepo.availables()
 
   """
-  @callback availables() :: List.t()
+  @callback availables() :: [Nabo.Post.slug()]
 end

test/integration_test.exs

@@ -4,7 +4,7 @@ defmodule Nabo.IntegrationTest do
   alias Nabo.TestRepos
 
   test "get/1 with a short markdown" do
-    assert {:ok, post} = TestRepos.Default.get("this-year-0202")
+    assert post = TestRepos.Default.get("this-year-0202")
 
     assert post.title == "This year 02-02"
     assert post.slug == "this-year-0202"
@@ -15,11 +15,11 @@ defmodule Nabo.IntegrationTest do
     assert post.body == "### Welcome!\n\nThis is your first blog post built with *Nabo blog engine*\n"
     assert post.body_html == "<h3>Welcome!</h3>\n<p>This is your first blog post built with <em>Nabo blog engine</em></p>\n"
 
-    assert {:error, _} = TestRepos.Default.get("something-that-does-not-exist")
+    assert TestRepos.Default.get("something-that-does-not-exist") == nil
   end
 
   test "get/1 with a long markdown" do
-    assert {:ok, post} = TestRepos.Default.get("this-year-0101")
+    assert post = TestRepos.Default.get("this-year-0101")
 
     assert post.title == "This year 01-01"
     assert post.slug == "this-year-0101"
@@ -28,11 +28,11 @@ defmodule Nabo.IntegrationTest do
     assert post.excerpt == "This is the post for 01-01"
     assert post.excerpt_html == "<p>This is the post for 01-01</p>\n"
 
-    assert {:error, _} = TestRepos.Default.get("something-that-does-not-exist")
+    assert TestRepos.Default.get("something-that-does-not-exist") == nil
   end
 
   test "get/1 with customized compiler" do
-    assert {:ok, post} = TestRepos.Customized.get("this-year-0303")
+    assert post = TestRepos.Customized.get("this-year-0303")
 
     assert post.body == "### Welcome!\n\n```elixir\na = 1\n```\n"
     assert post.body_html == "<h3>Welcome!</h3>\n<pre><code class=\"elixir nabo-elixir\">a = 1</code></pre>\n"