grpc: revert #8278: Fix cardinality violations in non-server streaming RPCs (#8404)

This reverts commit a64d933.

Author: arjan-bal

stream.go

@@ -1138,10 +1138,6 @@ func (a *csAttempt) recvMsg(m any, payInfo *payloadInfo) (err error) {
 			if statusErr := a.transportStream.Status().Err(); statusErr != nil {
 				return statusErr
 			}
-			// Received no msg and status OK for non-server streaming rpcs.
-			if !cs.desc.ServerStreams {
-				return status.Error(codes.Internal, "cardinality violation: received no response message from non-streaming RPC")
-			}
 			return io.EOF // indicates successful end of stream.
 		}
 
@@ -1175,7 +1171,7 @@ func (a *csAttempt) recvMsg(m any, payInfo *payloadInfo) (err error) {
 	} else if err != nil {
 		return toRPCErr(err)
 	}
-	return status.Error(codes.Internal, "cardinality violation: expected <EOF> for non server-streaming RPCs, but received another message")
+	return status.Errorf(codes.Internal, "cardinality violation: expected <EOF> for non server-streaming RPCs, but received another message")
 }
 
 func (a *csAttempt) finish(err error) {
@@ -1482,10 +1478,6 @@ func (as *addrConnStream) RecvMsg(m any) (err error) {
 			if statusErr := as.transportStream.Status().Err(); statusErr != nil {
 				return statusErr
 			}
-			// Received no msg and status OK for non-server streaming rpcs.
-			if !as.desc.ServerStreams {
-				return status.Error(codes.Internal, "cardinality violation: received no response message from non-streaming RPC")
-			}
 			return io.EOF // indicates successful end of stream.
 		}
 		return toRPCErr(err)
@@ -1503,7 +1495,7 @@ func (as *addrConnStream) RecvMsg(m any) (err error) {
 	} else if err != nil {
 		return toRPCErr(err)
 	}
-	return status.Error(codes.Internal, "cardinality violation: expected <EOF> for non server-streaming RPCs, but received another message")
+	return status.Errorf(codes.Internal, "cardinality violation: expected <EOF> for non server-streaming RPCs, but received another message")
 }
 
 func (as *addrConnStream) finish(err error) {

test/end2end_test.go

@@ -3589,6 +3589,9 @@ func testClientStreamingError(t *testing.T, e env) {
 // Tests that a client receives a cardinality violation error for client-streaming
 // RPCs if the server doesn't send a message before returning status OK.
 func (s) TestClientStreamingCardinalityViolation_ServerHandlerMissingSendAndClose(t *testing.T) {
+	// TODO : https://github.com/grpc/grpc-go/issues/8119 - remove `t.Skip()`
+	// after this is fixed.
+	t.Skip()
 	ss := &stubserver.StubServer{
 		StreamingInputCallF: func(_ testgrpc.TestService_StreamingInputCallServer) error {
 			// Returning status OK without sending a response message.This is a
@@ -3737,113 +3740,8 @@ func (s) TestClientStreaming_ReturnErrorAfterSendAndClose(t *testing.T) {
 	}
 }
 
-// Tests that a client receives a cardinality violation error for unary
-// RPCs if the server doesn't send a message before returning status OK.
-func (s) TestUnaryRPC_ServerSendsOnlyTrailersWithOK(t *testing.T) {
-	lis, err := testutils.LocalTCPListener()
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer lis.Close()
-
-	ss := grpc.UnknownServiceHandler(func(any, grpc.ServerStream) error {
-		return nil
-	})
-
-	s := grpc.NewServer(ss)
-	go s.Serve(lis)
-	defer s.Stop()
-
-	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
-	defer cancel()
-	cc, err := grpc.NewClient(lis.Addr().String(), grpc.WithTransportCredentials(insecure.NewCredentials()))
-	if err != nil {
-		t.Fatalf("grpc.NewClient(%q) failed unexpectedly: %v", lis.Addr(), err)
-	}
-	defer cc.Close()
-
-	client := testgrpc.NewTestServiceClient(cc)
-	if _, err = client.EmptyCall(ctx, &testpb.Empty{}); status.Code(err) != codes.Internal {
-		t.Errorf("stream.RecvMsg() = %v, want error %v", status.Code(err), codes.Internal)
-	}
-}
-
-// Tests that client will receive cardinality violations when calling
-// RecvMsg() multiple times for non-streaming response streams.
-func (s) TestUnaryRPC_ClientCallRecvMsgTwice(t *testing.T) {
-	e := tcpTLSEnv
-	te := newTest(t, e)
-	defer te.tearDown()
-
-	te.startServer(&testServer{security: e.security})
-
-	cc := te.clientConn()
-	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
-	defer cancel()
-
-	desc := &grpc.StreamDesc{
-		StreamName:    "UnaryCall",
-		ServerStreams: false,
-		ClientStreams: false,
-	}
-	stream, err := cc.NewStream(ctx, desc, "/grpc.testing.TestService/UnaryCall")
-	if err != nil {
-		t.Fatalf("cc.NewStream() failed unexpectedly: %v", err)
-	}
-
-	if err := stream.SendMsg(&testpb.SimpleRequest{}); err != nil {
-		t.Fatalf("stream.SendMsg(_) = %v, want <nil>", err)
-	}
-
-	resp := &testpb.SimpleResponse{}
-	if err := stream.RecvMsg(resp); err != nil {
-		t.Fatalf("stream.RecvMsg() = %v , want <nil>", err)
-	}
-
-	if err = stream.RecvMsg(resp); status.Code(err) != codes.Internal {
-		t.Errorf("stream.RecvMsg() = %v, want error %v", status.Code(err), codes.Internal)
-	}
-}
-
-// Tests that client will receive cardinality violations when calling
-// RecvMsg() multiple times for non-streaming response streams.
-func (s) TestClientStreaming_ClientCallRecvMsgTwice(t *testing.T) {
-	ss := stubserver.StubServer{
-		StreamingInputCallF: func(stream testgrpc.TestService_StreamingInputCallServer) error {
-			if err := stream.SendAndClose(&testpb.StreamingInputCallResponse{}); err != nil {
-				t.Errorf("stream.SendAndClose(_) = %v, want <nil>", err)
-			}
-			return nil
-		},
-	}
-	if err := ss.Start(nil); err != nil {
-		t.Fatal("Error starting server:", err)
-	}
-	defer ss.Stop()
-
-	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
-	defer cancel()
-	stream, err := ss.Client.StreamingInputCall(ctx)
-	if err != nil {
-		t.Fatalf(".StreamingInputCall(_) = _, %v, want <nil>", err)
-	}
-	if err := stream.Send(&testpb.StreamingInputCallRequest{}); err != nil {
-		t.Fatalf("stream.Send(_) = %v, want <nil>", err)
-	}
-	if err := stream.CloseSend(); err != nil {
-		t.Fatalf("stream.CloseSend() = %v, want <nil>", err)
-	}
-	resp := new(testpb.StreamingInputCallResponse)
-	if err := stream.RecvMsg(resp); err != nil {
-		t.Fatalf("stream.RecvMsg() = %v , want <nil>", err)
-	}
-	if err = stream.RecvMsg(resp); status.Code(err) != codes.Internal {
-		t.Errorf("stream.RecvMsg() = %v, want error %v", status.Code(err), codes.Internal)
-	}
-}
-
 // Tests that a client receives a cardinality violation error for client-streaming
-// RPCs if the server call SendMsg() multiple times.
+// RPCs if the server call SendMsg multiple times.
 func (s) TestClientStreaming_ServerHandlerSendMsgAfterSendMsg(t *testing.T) {
 	ss := stubserver.StubServer{
 		StreamingInputCallF: func(stream testgrpc.TestService_StreamingInputCallServer) error {