Init the project.

test/decentralised_book_index_web/controllers/error_html_test.exs

@@ -0,0 +1,15 @@
+defmodule DecentralisedBookIndexWeb.ErrorHTMLTest do
+  use DecentralisedBookIndexWeb.ConnCase, async: true
+
+  # Bring render_to_string/4 for testing custom views
+  import Phoenix.Template
+
+  test "renders 404.html" do
+    assert render_to_string(DecentralisedBookIndexWeb.ErrorHTML, "404", "html", []) == "Not Found"
+  end
+
+  test "renders 500.html" do
+    assert render_to_string(DecentralisedBookIndexWeb.ErrorHTML, "500", "html", []) ==
+             "Internal Server Error"
+  end
+end

test/decentralised_book_index_web/controllers/error_json_test.exs

@@ -0,0 +1,14 @@
+defmodule DecentralisedBookIndexWeb.ErrorJSONTest do
+  use DecentralisedBookIndexWeb.ConnCase, async: true
+
+  test "renders 404" do
+    assert DecentralisedBookIndexWeb.ErrorJSON.render("404.json", %{}) == %{
+             errors: %{detail: "Not Found"}
+           }
+  end
+
+  test "renders 500" do
+    assert DecentralisedBookIndexWeb.ErrorJSON.render("500.json", %{}) ==
+             %{errors: %{detail: "Internal Server Error"}}
+  end
+end

test/decentralised_book_index_web/controllers/page_controller_test.exs

@@ -0,0 +1,8 @@
+defmodule DecentralisedBookIndexWeb.PageControllerTest do
+  use DecentralisedBookIndexWeb.ConnCase
+
+  test "GET /", %{conn: conn} do
+    conn = get(conn, ~p"/")
+    assert html_response(conn, 200) =~ "Peace of mind from prototype to production"
+  end
+end

test/support/conn_case.ex

@@ -0,0 +1,38 @@
+defmodule DecentralisedBookIndexWeb.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 DecentralisedBookIndexWeb.ConnCase, async: true`, although
+  this option is not recommended for other databases.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      # The default endpoint for testing
+      @endpoint DecentralisedBookIndexWeb.Endpoint
+
+      use DecentralisedBookIndexWeb, :verified_routes
+
+      # Import conveniences for testing with connections
+      import Plug.Conn
+      import Phoenix.ConnTest
+      import DecentralisedBookIndexWeb.ConnCase
+    end
+  end
+
+  setup tags do
+    DecentralisedBookIndex.DataCase.setup_sandbox(tags)
+    {:ok, conn: Phoenix.ConnTest.build_conn()}
+  end
+end

test/support/data_case.ex

@@ -0,0 +1,62 @@
+defmodule DecentralisedBookIndex.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 DecentralisedBookIndex.DataCase, async: true`, although
+  this option is not recommended for other databases.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      alias DecentralisedBookIndex.Repo
+
+      import Ecto
+      import Ecto.Changeset
+      import Ecto.Query
+      import DecentralisedBookIndex.DataCase
+    end
+  end
+
+  setup tags do
+    DecentralisedBookIndex.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!(DecentralisedBookIndex.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/test_helper.exs

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