lecutre 07

lectures/07/bcit/test/support/conn_case.ex

@@ -0,0 +1,79 @@
+defmodule BcitWeb.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 BcitWeb.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 BcitWeb.Endpoint
+
+      use BcitWeb, :verified_routes
+
+      # Import conveniences for testing with connections
+      import Plug.Conn
+      import Phoenix.ConnTest
+      import BcitWeb.ConnCase
+    end
+  end
+
+  setup tags do
+    Bcit.DataCase.setup_sandbox(tags)
+    {:ok, conn: Phoenix.ConnTest.build_conn()}
+  end
+
+  @doc """
+  Setup helper that registers and logs in users.
+
+      setup :register_and_log_in_user
+
+  It stores an updated connection and a registered user in the
+  test context.
+  """
+  def register_and_log_in_user(%{conn: conn} = context) do
+    user = Bcit.AccountsFixtures.user_fixture()
+    scope = Bcit.Accounts.Scope.for_user(user)
+
+    opts =
+      context
+      |> Map.take([:token_authenticated_at])
+      |> Enum.into([])
+
+    %{conn: log_in_user(conn, user, opts), user: user, scope: scope}
+  end
+
+  @doc """
+  Logs the given `user` into the `conn`.
+
+  It returns an updated `conn`.
+  """
+  def log_in_user(conn, user, opts \\ []) do
+    token = Bcit.Accounts.generate_user_session_token(user)
+
+    maybe_set_token_authenticated_at(token, opts[:token_authenticated_at])
+
+    conn
+    |> Phoenix.ConnTest.init_test_session(%{})
+    |> Plug.Conn.put_session(:user_token, token)
+  end
+
+  defp maybe_set_token_authenticated_at(_token, nil), do: nil
+
+  defp maybe_set_token_authenticated_at(token, authenticated_at) do
+    Bcit.AccountsFixtures.override_token_authenticated_at(token, authenticated_at)
+  end
+end

lectures/07/bcit/test/support/data_case.ex

@@ -0,0 +1,58 @@
+defmodule Bcit.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 Bcit.DataCase, async: true`, although
+  this option is not recommended for other databases.
+  """
+
+  use ExUnit.CaseTemplate
+
+  using do
+    quote do
+      alias Bcit.Repo
+
+      import Ecto
+      import Ecto.Changeset
+      import Ecto.Query
+      import Bcit.DataCase
+    end
+  end
+
+  setup tags do
+    Bcit.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!(Bcit.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

lectures/07/bcit/test/support/fixtures/accounts_fixtures.ex

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+defmodule Bcit.AccountsFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `Bcit.Accounts` context.
+  """
+
+  import Ecto.Query
+
+  alias Bcit.Accounts
+  alias Bcit.Accounts.Scope
+
+  def unique_user_email, do: "user#{System.unique_integer()}@example.com"
+  def valid_user_password, do: "hello world!"
+
+  def valid_user_attributes(attrs \\ %{}) do
+    Enum.into(attrs, %{
+      email: unique_user_email()
+    })
+  end
+
+  def unconfirmed_user_fixture(attrs \\ %{}) do
+    {:ok, user} =
+      attrs
+      |> valid_user_attributes()
+      |> Accounts.register_user()
+
+    user
+  end
+
+  def user_fixture(attrs \\ %{}) do
+    user = unconfirmed_user_fixture(attrs)
+
+    token =
+      extract_user_token(fn url ->
+        Accounts.deliver_login_instructions(user, url)
+      end)
+
+    {:ok, {user, _expired_tokens}} =
+      Accounts.login_user_by_magic_link(token)
+
+    user
+  end
+
+  def user_scope_fixture do
+    user = user_fixture()
+    user_scope_fixture(user)
+  end
+
+  def user_scope_fixture(user) do
+    Scope.for_user(user)
+  end
+
+  def set_password(user) do
+    {:ok, {user, _expired_tokens}} =
+      Accounts.update_user_password(user, %{password: valid_user_password()})
+
+    user
+  end
+
+  def extract_user_token(fun) do
+    {:ok, captured_email} = fun.(&"[TOKEN]#{&1}[TOKEN]")
+    [_, token | _] = String.split(captured_email.text_body, "[TOKEN]")
+    token
+  end
+
+  def override_token_authenticated_at(token, authenticated_at) when is_binary(token) do
+    Bcit.Repo.update_all(
+      from(t in Accounts.UserToken,
+        where: t.token == ^token
+      ),
+      set: [authenticated_at: authenticated_at]
+    )
+  end
+
+  def generate_user_magic_link_token(user) do
+    {encoded_token, user_token} = Accounts.UserToken.build_email_token(user, "login")
+    Bcit.Repo.insert!(user_token)
+    {encoded_token, user_token.token}
+  end
+
+  def offset_user_token(token, amount_to_add, unit) do
+    dt = DateTime.add(DateTime.utc_now(:second), amount_to_add, unit)
+
+    Bcit.Repo.update_all(
+      from(ut in Accounts.UserToken, where: ut.token == ^token),
+      set: [inserted_at: dt, authenticated_at: dt]
+    )
+  end
+end

lectures/07/bcit/test/support/fixtures/schools_fixtures.ex

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+defmodule Bcit.SchoolsFixtures do
+  @moduledoc """
+  This module defines test helpers for creating
+  entities via the `Bcit.Schools` context.
+  """
+
+  @doc """
+  Generate a unique student sid.
+  """
+  def unique_student_sid do
+    "A" <> (System.unique_integer([:positive]) |> Integer.to_string() |> String.pad_leading(8, "0"))
+  end
+
+  @doc """
+  Generate a student.
+  """
+  def student_fixture(attrs \\ %{}) do
+    {:ok, student} =
+      attrs
+      |> Enum.into(%{
+        firstname: "some firstname",
+        gpa: 85.5,
+        lastname: "some lastname",
+        sid: unique_student_sid()
+      })
+      |> Bcit.Schools.create_student()
+
+    student
+  end
+end