add a file read test

test/mindwendel_web/controllers/file_controller_test.exs

@@ -0,0 +1,23 @@
+defmodule MindwendelWeb.FileControllerTest do
+  use MindwendelWeb.ConnCase
+  alias Mindwendel.Services.Vault
+  alias Mindwendel.Factory
+
+  @file_dest Path.join("priv/static/uploads", "encrypted-test.jpg")
+
+  describe "get_file" do
+    setup do
+      {:ok, encrypted_file} = Vault.encrypt("test")
+      File.write(@file_dest, encrypted_file)
+
+      on_exit(fn -> File.rm(@file_dest) end)
+      :ok
+    end
+
+    test "successfully retrieves an existing file", %{conn: conn} do
+      file = Factory.insert!(:file, path: "/uploads/encrypted-test.jpg", name: "test.jpg")
+
+      assert get(conn, ~p"/files/#{file.id}").resp_body == "test"
+    end
+  end
+end