Support no-op error responses (#186)

* support no-op err responses

* changes as oper review

Author: aarshkshah1992

go.sum

@@ -442,6 +442,11 @@ func (m *manager) processRevalidationResult(chid datatransfer.ChannelID, result
 			return nil, err
 		}
 	}
+
+	if resultErr == nil {
+		return vresMessage, nil
+	}
+
 	if resultErr == datatransfer.ErrPause {
 		err := m.pause(chid)
 		if err != nil {
@@ -450,7 +455,7 @@ func (m *manager) processRevalidationResult(chid datatransfer.ChannelID, result
 		return vresMessage, datatransfer.ErrPause
 	}
 
-	if resultErr == nil {
+	if resultErr == datatransfer.ErrResume {
 		err = m.resume(chid)
 		if err != nil {
 			return nil, err

impl/events.go

@@ -1030,7 +1030,7 @@ func TestSimulatedRetrievalFlow(t *testing.T) {
 			srv := &retrievalRevalidator{
 				testutil.NewStubbedRevalidator(), 0, 0, config.pausePoints, finalVoucherResult,
 			}
-			srv.ExpectSuccessRevalidation()
+			srv.ExpectSuccessErrResume()
 			require.NoError(t, dt1.RegisterRevalidator(testutil.NewFakeDTType(), srv))
 
 			require.NoError(t, dt2.RegisterVoucherResultType(testutil.NewFakeDTType()))

impl/integration_test.go

@@ -197,6 +197,10 @@ func TestDataTransferResponding(t *testing.T) {
 				sv.ExpectSuccessPush()
 				sv.StubResult(testutil.NewFakeDTType())
 			},
+			configureRevalidator: func(sv *testutil.StubbedRevalidator) {
+				sv.ExpectSuccessErrResume()
+			},
+
 			verify: func(t *testing.T, h *receiverHarness) {
 				h.network.Delegate.ReceiveRequest(h.ctx, h.peers[1], h.pushRequest)
 				_, err := h.transport.EventHandler.OnRequestReceived(channelID(h.id, h.peers), h.voucherUpdate)
@@ -278,7 +282,7 @@ func TestDataTransferResponding(t *testing.T) {
 			configureRevalidator: func(srv *testutil.StubbedRevalidator) {
 				srv.ExpectPausePushCheck()
 				srv.StubRevalidationResult(testutil.NewFakeDTType())
-				srv.ExpectSuccessRevalidation()
+				srv.ExpectSuccessErrResume()
 				srv.StubCheckResult(testutil.NewFakeDTType())
 			},
 			verify: func(t *testing.T, h *receiverHarness) {
@@ -415,7 +419,7 @@ func TestDataTransferResponding(t *testing.T) {
 			configureRevalidator: func(srv *testutil.StubbedRevalidator) {
 				srv.ExpectPausePullCheck()
 				srv.StubRevalidationResult(testutil.NewFakeDTType())
-				srv.ExpectSuccessRevalidation()
+				srv.ExpectSuccessErrResume()
 				srv.StubCheckResult(testutil.NewFakeDTType())
 			},
 			verify: func(t *testing.T, h *receiverHarness) {
@@ -464,7 +468,7 @@ func TestDataTransferResponding(t *testing.T) {
 			configureRevalidator: func(srv *testutil.StubbedRevalidator) {
 				srv.ExpectPauseComplete()
 				srv.StubRevalidationResult(testutil.NewFakeDTType())
-				srv.ExpectSuccessRevalidation()
+				srv.ExpectSuccessErrResume()
 			},
 			verify: func(t *testing.T, h *receiverHarness) {
 				_, err := h.transport.EventHandler.OnRequestReceived(channelID(h.id, h.peers), h.pullRequest)

impl/responding_test.go

@@ -38,7 +38,7 @@ func (m *manager) newRequest(ctx context.Context, selector ipld.Node, isPull boo
 }
 
 func (m *manager) response(isRestart bool, isNew bool, err error, tid datatransfer.TransferID, voucherResult datatransfer.VoucherResult) (datatransfer.Response, error) {
-	isAccepted := err == nil || err == datatransfer.ErrPause
+	isAccepted := err == nil || err == datatransfer.ErrPause || err == datatransfer.ErrResume
 	isPaused := err == datatransfer.ErrPause
 	resultType := datatransfer.EmptyTypeIdentifier
 	if voucherResult != nil {
@@ -55,7 +55,7 @@ func (m *manager) response(isRestart bool, isNew bool, err error, tid datatransf
 }
 
 func (m *manager) completeResponse(err error, tid datatransfer.TransferID, voucherResult datatransfer.VoucherResult) (datatransfer.Response, error) {
-	isAccepted := err == nil || err == datatransfer.ErrPause
+	isAccepted := err == nil || err == datatransfer.ErrPause || err == datatransfer.ErrResume
 	isPaused := err == datatransfer.ErrPause
 	resultType := datatransfer.EmptyTypeIdentifier
 	if voucherResult != nil {

impl/utils.go

@@ -313,6 +313,13 @@ func (srv *StubbedRevalidator) StubPauseRevalidation() {
 	srv.revalidationError = datatransfer.ErrPause
 }
 
+// ExpectSuccessErrResume configures Revalidate to return an ErrResume
+// and expect a Revalidate call.
+func (srv *StubbedRevalidator) ExpectSuccessErrResume() {
+	srv.expectRevalidate = true
+	srv.revalidationError = datatransfer.ErrResume
+}
+
 // ExpectErrorRevalidation expects Revalidate to error
 func (srv *StubbedRevalidator) ExpectErrorRevalidation() {
 	srv.expectRevalidate = true