Function TestUserMessageOrdinalToItemIndex

pkg/server/session_manager_test.go:524–558

TestUserMessageOrdinalToItemIndex covers the ordinal translation helper: only user-role messages count; system and assistant items are skipped; out-of-range ordinals are rejected.

(t *testing.T)

// helper: only user-role messages count; system and assistant items
// are skipped; out-of-range ordinals are rejected.
func TestUserMessageOrdinalToItemIndex(t *testing.T) {
	t.Parallel()

	sess := session.New()
	// Items 0..3: user, system, assistant, user. Ordinal 0 → item 0,
	// ordinal 1 → item 3.
	sess.Messages = []session.Item{
		session.NewMessageItem(session.UserMessage("u1")),
		session.NewMessageItem(&session.Message{
			Message: chat.Message{Role: chat.MessageRoleSystem, Content: "sys"},
		}),
		session.NewMessageItem(session.NewAgentMessage("root", &chat.Message{
			Role:    chat.MessageRoleAssistant,
			Content: "a1",
		})),
		session.NewMessageItem(session.UserMessage("u2")),
	}

	idx, err := userMessageOrdinalToItemIndex(sess, 0)
	require.NoError(t, err)
	assert.Equal(t, 0, idx)

	idx, err = userMessageOrdinalToItemIndex(sess, 1)
	require.NoError(t, err)
	assert.Equal(t, 3, idx, "ordinal 1 must skip past the system and assistant items")

	_, err = userMessageOrdinalToItemIndex(sess, 2)
	require.ErrorIs(t, err, ErrForkOutOfRange)

	_, err = userMessageOrdinalToItemIndex(sess, -1)
	require.ErrorIs(t, err, ErrForkOutOfRange)

	_, err = userMessageOrdinalToItemIndex(sess, 99)
	require.ErrorIs(t, err, ErrForkOutOfRange)
}