Complete step 3 of the migration plan and clean up the implemented roadmap

engine_test.go

@@ -610,6 +610,8 @@ func TestRunPassesPreparedRequestToInjectedLLMClient(t *testing.T) {
 }
 
 func TestEngineRunPropagatesCallerCancellation(t *testing.T) {
+	const synchronizationTimeout = 5 * time.Second
+
 	started := make(chan struct{})
 	transport := roundTripFunc(func(req *http.Request) (*http.Response, error) {
 		close(started)
@@ -640,10 +642,24 @@ func TestEngineRunPropagatesCallerCancellation(t *testing.T) {
 		result <- err
 	}()
 
-	<-started
+	watchdog := time.NewTimer(synchronizationTimeout)
+	defer watchdog.Stop()
+	select {
+	case <-started:
+	case err := <-result:
+		t.Fatalf("Engine.Run returned before the transport started: %v", err)
+	case <-watchdog.C:
+		t.Fatal("timed out waiting for the transport to start")
+	}
+
 	cancel()
-	if err := <-result; !errors.Is(err, scriptorium.ErrLLMGenerate) {
-		t.Fatalf("expected ErrLLMGenerate after caller cancellation, got %v", err)
+	select {
+	case err := <-result:
+		if !errors.Is(err, scriptorium.ErrLLMGenerate) {
+			t.Fatalf("expected ErrLLMGenerate after caller cancellation, got %v", err)
+		}
+	case <-watchdog.C:
+		t.Fatal("timed out waiting for Engine.Run to return after cancellation")
 	}
 }