Drop session

lib/plausible_web/plugs/session_timeout_plug.ex

@@ -9,19 +9,16 @@ defmodule PlausibleWeb.SessionTimeoutPlug do
     timeout_at = get_session(conn, :session_timeout_at)
     user_id = get_session(conn, :current_user_id)
 
-    if user_id && timeout_at && now() > timeout_at do
+    cond do
-      logout_user(conn)
+      user_id && timeout_at && now() > timeout_at ->
-    else
+        configure_session(conn, drop: true)
-      put_session(conn, :session_timeout_at, new_session_timeout_at(opts[:timeout_after_seconds]))
+      user_id ->
+        put_session(conn, :session_timeout_at, new_session_timeout_at(opts[:timeout_after_seconds]))
+      true ->
+        conn
     end
   end
 
-  defp logout_user(conn) do
-    conn
-    |> put_session(:current_user_id, nil) # Leave `device_id` in the session for accurate tracking
-    |> assign(:session_timeout, true)
-  end
-
   defp now do
     DateTime.utc_now() |> DateTime.to_unix
   end

test/plausible_web/plugs/session_timeout_plug_test.exs

@@ -0,0 +1,32 @@
+defmodule PlausibleWeb.SessionTimeoutPlugTest do
+  use ExUnit.Case, async: true
+  use Plug.Test
+  alias PlausibleWeb.SessionTimeoutPlug
+  @opts %{timeout_after_seconds: 10}
+
+  test "does nothing if user is not logged in" do
+    conn = conn(:get, "/")
+           |> init_test_session(%{})
+           |> SessionTimeoutPlug.call(@opts)
+
+    refute get_session(conn, :session_timeout_at)
+  end
+
+  test "sets session timeout if user is logged in" do
+    conn = conn(:get, "/")
+           |> init_test_session(%{current_user_id: 1})
+           |> SessionTimeoutPlug.call(@opts)
+
+    timeout = get_session(conn, :session_timeout_at)
+    now = DateTime.utc_now() |> DateTime.to_unix
+    assert timeout > now
+  end
+
+  test "logs user out if timeout passed" do
+    conn = conn(:get, "/")
+           |> init_test_session(%{current_user_id: 1, session_timeout_at: 1})
+           |> SessionTimeoutPlug.call(@opts)
+
+    assert conn.private[:plug_session_info] == :drop
+  end
+end