Function TestSteer_EmptySessionBootstrap

pkg/runtime/runtime_test.go:3469–3560

TestSteer_EmptySessionBootstrap verifies that when RunStream is started with zero messages in the session but one or more messages already queued via Steer, the model receives those messages as its initial context — i.e. the run completes normally rather than erroring or producing a vacuous response

(t *testing.T)

// response. The behaviour must be identical to a session where those messages
// were added directly via session.WithUserMessage before the call.
func TestSteer_EmptySessionBootstrap(t *testing.T) {
	t.Parallel()

	stream := newStreamBuilder().
		AddContent("Hello from the model").
		AddStopWithUsage(5, 3).
		Build()

	prov := &messageRecordingProvider{
		id:      "test/mock-model",
		streams: []*mockStream{stream},
	}

	root := agent.New("root", "You are a test agent", agent.WithModel(prov))
	tm := team.New(team.WithAgents(root))

	rt, err := NewLocalRuntime(t.Context(), tm, WithSessionCompaction(false), WithModelStore(mockModelStore{}))
	require.NoError(t, err)

	// Enqueue before RunStream — zero messages in the session.
	err = rt.Steer(t.Context(), QueuedMessage{Content: "bootstrap message"})
	require.NoError(t, err)

	// Fresh session with NO messages (SendUserMessage defaults to true but
	// there is nothing to send yet).
	sess := session.New()
	sess.Title = "steer bootstrap test"

	evCh := rt.RunStream(t.Context(), sess)
	var events []Event
	for ev := range evCh {
		events = append(events, ev)
	}

	// The run must complete normally.
	require.NotEmpty(t, events)
	assert.IsType(t, &StreamStoppedEvent{}, events[len(events)-1],
		"expected StreamStopped as the final event; got %T", events[len(events)-1])

	// A UserMessageEvent must have been emitted for the steer message.
	var steerEventFound bool
	for _, ev := range events {
		if ue, ok := ev.(*UserMessageEvent); ok && strings.Contains(ue.Message, "bootstrap message") {
			steerEventFound = true
			break
		}
	}
	assert.True(t, steerEventFound,
		"expected a UserMessageEvent for the bootstrap steer message")

	// --- Session-message assertions ---
	// The stored session message must be plain — no system-reminder envelope.
	var bootstrapMsg *session.Message
	for _, item := range sess.Messages {
		if item.IsMessage() &&
			item.Message.Message.Role == chat.MessageRoleUser &&
			strings.Contains(item.Message.Message.Content, "bootstrap message") {
			bootstrapMsg = item.Message