Refactor the Links module.

CHANGELOG.org

@@ -32,4 +32,10 @@
     Fix Links.update_one/2.
 ** 0.4.5 <2023-08-01 Tue>
     Fix the route path in LinkController.create/2.
+** 0.4.6 <2023-08-01 Tue>
+    Add the API to update the Link model.
+** 0.4.7 <2023-08-01 Tue>
+    Add tests for the API.
+** 0.4.8 <2023-08-02 Wed>
+    Refactor the Links module.
 

lib/link_shortener/links/links.ex

@@ -1,4 +1,4 @@
-defmodule LinkShortener.Links.Links do
+defmodule LinkShortener.Links do
   use Ecto.Schema
   import Ecto.Changeset
   import Ecto.Query
@@ -6,11 +6,12 @@ defmodule LinkShortener.Links.Links do
   alias LinkShortener.Links.Link
   alias LinkShortener.Generators.SafeString
 
-  def new_one(), do: Link.changeset(%Link{})
+  def new_one(), do: Link.changeset(%Link{}, %{})
 
   def create_one(attrs, length \\ 10, generator \\ SafeString) do
     shorten = generator.generate(length)
-    insert_one(Map.put(attrs, :shorten, shorten))
+    Map.put(attrs, :shorten, shorten)
+    |> insert_one()
   end
 
   def insert_one(attrs) do
@@ -19,25 +20,10 @@ defmodule LinkShortener.Links.Links do
     |> Repo.insert()
   end
 
-  def edit_one(id) do
+  def get_one!(id) do
-    get_one(id)
+    Repo.get!(Link, id)
-    |> Link.changeset()
   end
 
-  def update_one(%Link{} = link, changes) do
-    link
-    |> Link.changeset(changes)
-    |> Repo.update()
-  end
-
-  def insert_one(attrs) do
-    %Link{}
-    |> Link.changeset(attrs)
-    |> Repo.insert()
-  end
-
-  def delete_one(%Link{} = link), do: Repo.delete(link)
-
   def get_one_by(attrs) do
     Repo.get_by(Link, attrs)
   end
@@ -46,12 +32,26 @@ defmodule LinkShortener.Links.Links do
     get_one_by(%{shorten: shorten})
   end
 
-  def get_one(id) do
+  def get_all() do
-    Repo.get!(Link, id)
+    from(Link)
+    |> Repo.all()
   end
 
   def get_all(opts) do
     from(Link)
     |> Repo.all()
   end
+
+  def edit_one(%Link{} = link) do
+    link
+    |> Link.changeset(%{})
+  end
+
+  def update_one(%Link{} = link, changes) do
+    link
+    |> Link.changeset(changes)
+    |> Repo.update()
+  end
+
+  def delete_one(%Link{} = link), do: Repo.delete(link)
 end

lib/link_shortener_web/controllers/api/v1/link_controller.ex

@@ -1,13 +1,13 @@
 defmodule LinkShortenerWeb.Api.V1.LinkController do
   use LinkShortenerWeb, :controller
 
-  alias LinkShortener.Links.Links
+  alias LinkShortener.Links
   alias LinkShortener.Links.Link
 
   action_fallback LinkShortenerWeb.FallbackController
 
   def index(conn, _params) do
-    links = Links.get_all({})
+    links = Links.get_all()
     render(conn, "index.json", links: links)
   end
 
@@ -21,13 +21,20 @@ defmodule LinkShortenerWeb.Api.V1.LinkController do
   end
 
   def show(conn, %{"id" => id}) do
-    link = Links.get_one(id)
+    link = Links.get_one!(id)
     render(conn, "show.json", link: link)
   end
+
+  def update(conn, %{"id" => id, "link" => link_params}) do
+    link = Links.get_one!(id)
+
+    with {:ok, %Link{} = link} <- Links.update_one(link, link_params) do
+      render(conn, "show.json", link: link)
+    end
   end
 
   def delete(conn, %{"id" => id}) do
-    link = Links.get_one(id)
+    link = Links.get_one!(id)
 
     with {:ok, %Link{}} <- Links.delete_one(link) do
       send_resp(conn, :no_content, "")

test/link_shortener_web/controllers/api/v1/link_controller_test.exs

@@ -0,0 +1,97 @@
+defmodule LinkShortenerWeb.Api.V1.LinkControllerTest do
+  use LinkShortenerWeb.ConnCase
+
+  import LinkShortener.LinksFixtures
+
+  alias LinkShortener.Links.Link
+  alias LinkShortener.Links
+
+  @create_attrs %{
+    name: "some link name",
+    url: "https://gitlab.com/KKlochko/link_shortener",
+    shorten: "git_repo",
+  }
+  @update_attrs %{
+    name: "some updated link name",
+    url: "https://gitlab.com/KKlochko/link_shortener2",
+    shorten: "new_git_repo",
+  }
+  @invalid_attrs %{
+    name: nil,
+    url: nil,
+    shorten: nil,
+  }
+
+  setup %{conn: conn} do
+    {:ok, conn: put_req_header(conn, "accept", "application/json")}
+  end
+
+  describe "index" do
+    test "lists all links", %{conn: conn} do
+      conn = get(conn, Routes.v1_link_path(conn, :index))
+      assert json_response(conn, 200)["data"] == []
+    end
+  end
+
+  describe "create link" do
+    test "renders link when data is valid", %{conn: conn} do
+      conn = post(conn, Routes.v1_link_path(conn, :create), link: @create_attrs)
+      assert %{"id" => id} = json_response(conn, 201)["data"]
+
+      conn = get(conn, Routes.v1_link_path(conn, :show, id))
+
+      assert %{
+               "id" => ^id,
+	       "name" => "some link name",
+	       "url" => "https://gitlab.com/KKlochko/link_shortener",
+	       "shorten" => "git_repo",
+             } = json_response(conn, 200)["data"]
+    end
+
+    test "renders errors when data is invalid", %{conn: conn} do
+      conn = post(conn, Routes.v1_link_path(conn, :create), link: @invalid_attrs)
+      assert json_response(conn, 422)["errors"] != %{}
+    end
+  end
+
+  describe "update link" do
+    setup [:create_link]
+
+    test "renders link when data is valid", %{conn: conn, link: %Link{id: id} = link} do
+      conn = put(conn, Routes.v1_link_path(conn, :update, link), link: @update_attrs)
+      assert %{"id" => ^id} = json_response(conn, 200)["data"]
+
+      conn = get(conn, Routes.v1_link_path(conn, :show, id))
+
+      assert %{
+               "id" => ^id,
+	       "name" => "some updated link name",
+	       "url" => "https://gitlab.com/KKlochko/link_shortener2",
+	       "shorten" => "new_git_repo",
+             } = json_response(conn, 200)["data"]
+    end
+
+    test "renders errors when data is invalid", %{conn: conn, link: link} do
+      conn = put(conn, Routes.v1_link_path(conn, :update, link), link: @invalid_attrs)
+      assert json_response(conn, 422)["errors"] != %{}
+    end
+  end
+
+  describe "delete link" do
+    setup [:create_link]
+
+    test "deletes chosen link", %{conn: conn, link: link} do
+      conn = delete(conn, Routes.v1_link_path(conn, :delete, link))
+      assert response(conn, 204)
+
+      assert_error_sent 404, fn ->
+        get(conn, Routes.v1_link_path(conn, :show, link))
+      end
+    end
+  end
+
+  defp create_link(_) do
+    link = link_fixture()
+    %{link: link}
+  end
+end

test/link_shortener_web/controllers/page_controller_test.exs

@@ -0,0 +1,8 @@
+defmodule LinkShortenerWeb.PageControllerTest do
+  use LinkShortenerWeb.ConnCase
+
+  test "GET /", %{conn: conn} do
+    conn = get(conn, "/")
+    assert html_response(conn, 200) =~ "Usage"
+  end
+end

test/link_shortener_web/views/error_view_test.exs

@@ -0,0 +1,14 @@
+defmodule LinkShortenerWeb.ErrorViewTest do
+  use LinkShortenerWeb.ConnCase, async: true
+
+  # Bring render/3 and render_to_string/3 for testing custom views
+  import Phoenix.View
+
+  test "renders 404.html" do
+    assert render_to_string(LinkShortenerWeb.ErrorView, "404.html", []) == "Not Found"
+  end
+
+  test "renders 500.html" do
+    assert render_to_string(LinkShortenerWeb.ErrorView, "500.html", []) == "Internal Server Error"
+  end
+end

test/link_shortener_web/views/layout_view_test.exs

@@ -0,0 +1,8 @@
+defmodule LinkShortenerWeb.LayoutViewTest do
+  use LinkShortenerWeb.ConnCase, async: true
+
+  # When testing helpers, you may want to import Phoenix.HTML and
+  # use functions such as safe_to_string() to convert the helper
+  # result into an HTML string.
+  # import Phoenix.HTML
+end

test/link_shortener_web/views/page_view_test.exs

@@ -0,0 +1,3 @@
+defmodule LinkShortenerWeb.PageViewTest do
+  use LinkShortenerWeb.ConnCase, async: true
+end

test/support/conn_case.ex

@@ -0,0 +1,38 @@
+defmodule LinkShortenerWeb.ConnCase do
+  @moduledoc """
+  This module defines the test case to be used by
+  tests that require setting up a connection.
+
+  Such tests rely on `Phoenix.ConnTest` and also
+  import other functionality to make it easier
+  to build common data structures and query the data layer.
+
+  Finally, if the test case interacts with the database,
+  we enable the SQL sandbox, so changes done to the database
+  are reverted at the end of every test. If you are using
+  PostgreSQL, you can even run database tests asynchronously
+  by setting `use LinkShortenerWeb.ConnCase, async: true`, although
+  this option is not recommended for other databases.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      # Import conveniences for testing with connections
+      import Plug.Conn
+      import Phoenix.ConnTest
+      import LinkShortenerWeb.ConnCase
+
+      alias LinkShortenerWeb.Router.Helpers, as: Routes
+
+      # The default endpoint for testing
+      @endpoint LinkShortenerWeb.Endpoint
+    end
+  end
+
+  setup tags do
+    LinkShortener.DataCase.setup_sandbox(tags)
+    {:ok, conn: Phoenix.ConnTest.build_conn()}
+  end
+end

test/support/data_case.ex

@@ -0,0 +1,58 @@
+defmodule LinkShortener.DataCase do
+  @moduledoc """
+  This module defines the setup for tests requiring
+  access to the application's data layer.
+
+  You may define functions here to be used as helpers in
+  your tests.
+
+  Finally, if the test case interacts with the database,
+  we enable the SQL sandbox, so changes done to the database
+  are reverted at the end of every test. If you are using
+  PostgreSQL, you can even run database tests asynchronously
+  by setting `use LinkShortener.DataCase, async: true`, although
+  this option is not recommended for other databases.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      alias LinkShortener.Repo
+
+      import Ecto
+      import Ecto.Changeset
+      import Ecto.Query
+      import LinkShortener.DataCase
+    end
+  end
+
+  setup tags do
+    LinkShortener.DataCase.setup_sandbox(tags)
+    :ok
+  end
+
+  @doc """
+  Sets up the sandbox based on the test tags.
+  """
+  def setup_sandbox(tags) do
+    pid = Ecto.Adapters.SQL.Sandbox.start_owner!(LinkShortener.Repo, shared: not tags[:async])
+    on_exit(fn -> Ecto.Adapters.SQL.Sandbox.stop_owner(pid) end)
+  end
+
+  @doc """
+  A helper that transforms changeset errors into a map of messages.
+
+      assert {:error, changeset} = Accounts.create_user(%{password: "short"})
+      assert "password is too short" in errors_on(changeset).password
+      assert %{password: ["password is too short"]} = errors_on(changeset)
+
+  """
+  def errors_on(changeset) do
+    Ecto.Changeset.traverse_errors(changeset, fn {message, opts} ->
+      Regex.replace(~r"%{(\w+)}", message, fn _, key ->
+        opts |> Keyword.get(String.to_existing_atom(key), key) |> to_string()
+      end)
+    end)
+  end
+end

test/support/fixtures/links_fixtures.ex

@@ -0,0 +1,24 @@
+defmodule LinkShortener.LinksFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `LinkShortener.Links` context.
+  """
+
+  alias LinkShortener.Links
+
+  @doc """
+  Generate a link.
+  """
+  def link_fixture(attrs \\ %{}) do
+    {:ok, link} =
+      attrs
+      |> Enum.into(%{
+        name: "some name",
+	url: "https://gitlab.com/KKlochko/link_shortener",
+	shorten: "api-article",
+      })
+      |> Links.create_one()
+
+    link
+  end
+end

test/test_helper.exs

@@ -0,0 +1,2 @@
+ExUnit.start()
+Ecto.Adapters.SQL.Sandbox.mode(LinkShortener.Repo, :manual)