Updated with a few more tests.

restest/mockconn.go

@@ -322,6 +322,10 @@ func (c *MockConn) AssertNoSubscription(subj string) {
 func (c *MockConn) GetMsg() *Msg {
 	select {
 	case r := <-c.rch:
+		// Channel is closed
+		if r == nil {
+			return nil
+		}
 		return &Msg{
 			Msg: r,
 			c:   c,

restest/session.go

@@ -81,6 +81,10 @@ func NewSession(t *testing.T, service *res.Service, opts ...func(*SessionConfig)
 
 	if !s.cfg.NoReset {
 		msg := s.GetMsg()
+		if msg == nil {
+			// The channel is closed
+			t.Fatal("expected a system.reset, but got no message")
+		}
 		if s.cfg.ValidateReset {
 			msg.AssertSystemReset(cfg.ResetResources, cfg.ResetAccess)
 		} else {

test/00service_test.go

@@ -330,3 +330,53 @@ func TestServiceTokenReset(t *testing.T) {
 		})
 	}
 }
+
+// Test ServiceSetWorkerCount panics when called after starting service
+func TestServiceSetWorkerCount_AfterStart_Panics(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.Handle("model", res.Access(res.AccessGranted))
+	}, func(s *restest.Session) {
+		restest.AssertPanic(t, func() {
+			s.Service().SetWorkerCount(5)
+		})
+	})
+}
+
+// Test ServiceSetWorkerCount does not panic when zero
+func TestServiceSetWorkerCount_ZeroWorkerCount_DoesNotPanic(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.SetWorkerCount(0) // Default worker count should be used
+	}, nil, restest.WithoutReset)
+}
+
+// Test ServiceSetWorkerCount does not panic when greater than zero
+func TestServiceSetWorkerCount_GreaterThanZero_DoesNotPanic(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.SetWorkerCount(5)
+	}, nil, restest.WithoutReset)
+}
+
+// Test ServiceSetInChannelSize panics when called after starting service
+func TestServiceSetInChannelSize_AfterStart_Panics(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.Handle("model", res.Access(res.AccessGranted))
+	}, func(s *restest.Session) {
+		restest.AssertPanic(t, func() {
+			s.Service().SetInChannelSize(10)
+		})
+	})
+}
+
+// Test ServiceSetInChannelSize does not panic when zero
+func TestServiceSetInChannelSize_ZeroWorkerCount_DoesNotPanic(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.SetInChannelSize(0) // Default in channel size should be used
+	}, nil, restest.WithoutReset)
+}
+
+// Test ServiceSetInChannelSize does not panic when greater than zero
+func TestServiceSetInChannelSize_GreaterThanZero_DoesNotPanic(t *testing.T) {
+	runTest(t, func(s *res.Service) {
+		s.SetInChannelSize(10)
+	}, nil, restest.WithoutReset)
+}