Fix incorrect nil handling in workflowTaskPoller

internal/internal_task_pollers.go

@@ -290,14 +290,22 @@ func newWorkflowTaskPoller(
 	domain string,
 	params workerExecutionParameters,
 ) *workflowTaskPoller {
+	/*
+	Explicit nil handling is needed here. Otherwise, poller.ldaTunnel would not return a nil result
+	*/
+	var ldaTunnelInterface localDispatcher
+	if ldaTunnel != nil {
+		ldaTunnelInterface = ldaTunnel
+	}
+
 	return &workflowTaskPoller{
 		basePoller:                   basePoller{shutdownC: params.WorkerStopChannel},
 		service:                      service,
 		domain:                       domain,
 		taskListName:                 params.TaskList,
 		identity:                     params.Identity,
 		taskHandler:                  taskHandler,
-		ldaTunnel:                    ldaTunnel,
+		ldaTunnel:                    ldaTunnelInterface,
 		metricsScope:                 metrics.NewTaggedScope(params.MetricsScope),
 		logger:                       params.Logger,
 		stickyUUID:                   uuid.New(),

internal/internal_task_pollers_test.go

@@ -46,6 +46,21 @@ const (
 	_testIdentity   = "test-worker"
 )
 
+func Test_newWorkflowTaskPoller(t *testing.T) {
+	t.Run("success with nil ldaTunnel", func(t *testing.T) {
+		poller := newWorkflowTaskPoller(
+			nil,
+			nil,
+			nil,
+			_testDomainName,
+			workerExecutionParameters{})
+		assert.NotNil(t, poller)
+		if poller.ldaTunnel != nil {
+			t.Error("unexpected not nil ldaTunnel")
+		}
+	})
+}
+
 func TestLocalActivityPanic(t *testing.T) {
 	// regression: panics in local activities should not terminate the process
 	s := WorkflowTestSuite{logger: testlogger.NewZap(t)}