Function TestReasoningOnlyTurnEmitsWarning

pkg/runtime/runtime_test.go:4179–4206

TestReasoningOnlyTurnEmitsWarning is a regression test for https://github.com/docker/docker-agent/issues/3145. A thinking-mode model (e.g. Qwen3 via an openai_chatcompletions provider) can stream only reasoning tokens and then stop with no content and no tool calls. recordAssistantMessage skips that

(t *testing.T)

// runtime must instead surface a Warning explaining that the model produced only
// reasoning, and must still not persist an assistant message.
func TestReasoningOnlyTurnEmitsWarning(t *testing.T) {
	stream := newStreamBuilder().
		AddReasoning("The user wants the file list. ").
		AddReasoning("I should call list_directory.").
		AddStopWithUsage(10, 25).
		Build()

	sess := session.New(session.WithUserMessage("List the files"))
	events := runSession(t, sess, stream)

	var warn *WarningEvent
	assistantPersisted := false
	for _, ev := range events {
		switch e := ev.(type) {
		case *WarningEvent:
			warn = e
		case *MessageAddedEvent:
			if e.Message != nil && e.Message.Message.Role == chat.MessageRoleAssistant {
				assistantPersisted = true
			}
		}
	}

	require.NotNil(t, warn, "expected a Warning event for a reasoning-only turn")
	assert.Contains(t, warn.Message, "only reasoning")
	assert.False(t, assistantPersisted,
		"a reasoning-only turn must not persist an assistant message")
}

// TestEmptyTurnEmitsWarning verifies that a wholly empty turn (no content, no
// reasoning, no tool calls) - e.g. a rate-limited or token-capped provider that