pass micro errors from grpc server to grpc client (#1167)

* pass micro errors from grpc server to grpc client

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

* wrap micro errors.Error to grpc status

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

grpc.go

@@ -14,6 +14,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/golang/protobuf/proto"
 	"github.com/micro/go-micro/v2/broker"
 	"github.com/micro/go-micro/v2/codec"
 	"github.com/micro/go-micro/v2/errors"
@@ -375,20 +376,38 @@ func (g *grpcServer) processRequest(stream grpc.ServerStream, service *service,
 
 		statusCode := codes.OK
 		statusDesc := ""
-
 		// execute the handler
 		if appErr := fn(ctx, r, replyv.Interface()); appErr != nil {
-			if err, ok := appErr.(*rpcError); ok {
-				statusCode = err.code
-				statusDesc = err.desc
-			} else if err, ok := appErr.(*errors.Error); ok {
-				statusCode = microError(err)
-				statusDesc = appErr.Error()
-			} else {
+			var errStatus *status.Status
+			switch verr := appErr.(type) {
+			case *errors.Error:
+				// micro.Error now proto based and we can attach it to grpc status
+				statusCode = microError(verr)
+				statusDesc = verr.Error()
+				errStatus, err = status.New(statusCode, statusDesc).WithDetails(verr)
+				if err != nil {
+					return err
+				}
+			case proto.Message:
+				// user defined error that proto based we can attach it to grpc status
 				statusCode = convertCode(appErr)
 				statusDesc = appErr.Error()
+				errStatus, err = status.New(statusCode, statusDesc).WithDetails(verr)
+				if err != nil {
+					return err
+				}
+			case *rpcError:
+				// rpcError handling may be we have ability to attach it to details?
+				statusCode = verr.code
+				statusDesc = verr.desc
+				errStatus = status.New(statusCode, statusDesc)
+			default:
+				// default case user pass own error type that not proto based
+				statusCode = convertCode(verr)
+				statusDesc = verr.Error()
+				errStatus = status.New(statusCode, statusDesc)
 			}
-			return status.New(statusCode, statusDesc).Err()
+			return errStatus.Err()
 		}
 
 		if err := stream.SendMsg(replyv.Interface()); err != nil {
@@ -436,16 +455,37 @@ func (g *grpcServer) processStream(stream grpc.ServerStream, service *service, m
 
 	appErr := fn(ctx, r, ss)
 	if appErr != nil {
-		if err, ok := appErr.(*rpcError); ok {
-			statusCode = err.code
-			statusDesc = err.desc
-		} else if err, ok := appErr.(*errors.Error); ok {
-			statusCode = microError(err)
-			statusDesc = appErr.Error()
-		} else {
+		var err error
+		var errStatus *status.Status
+		switch verr := appErr.(type) {
+		case *errors.Error:
+			// micro.Error now proto based and we can attach it to grpc status
+			statusCode = microError(verr)
+			statusDesc = verr.Error()
+			errStatus, err = status.New(statusCode, statusDesc).WithDetails(verr)
+			if err != nil {
+				return err
+			}
+		case proto.Message:
+			// user defined error that proto based we can attach it to grpc status
 			statusCode = convertCode(appErr)
 			statusDesc = appErr.Error()
+			errStatus, err = status.New(statusCode, statusDesc).WithDetails(verr)
+			if err != nil {
+				return err
+			}
+		case *rpcError:
+			// rpcError handling may be we have ability to attach it to details?
+			statusCode = verr.code
+			statusDesc = verr.desc
+			errStatus = status.New(statusCode, statusDesc)
+		default:
+			// default case user pass own error type that not proto based
+			statusCode = convertCode(verr)
+			statusDesc = verr.Error()
+			errStatus = status.New(statusCode, statusDesc)
 		}
+		return errStatus.Err()
 	}
 
 	return status.New(statusCode, statusDesc).Err()

grpc_test.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"testing"
 
+	"github.com/micro/go-micro/v2/errors"
 	"github.com/micro/go-micro/v2/registry/memory"
 	"github.com/micro/go-micro/v2/server"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/status"
 
 	pb "github.com/micro/go-micro/v2/server/grpc/proto"
 )
@@ -16,6 +18,10 @@ type testServer struct{}
 
 // TestHello implements helloworld.GreeterServer
 func (s *testServer) Call(ctx context.Context, req *pb.Request, rsp *pb.Response) error {
+	if req.Name == "Error" {
+		return &errors.Error{Id: "1", Code: 99, Detail: "detail"}
+	}
+
 	rsp.Msg = "Hello " + req.Name
 	return nil
 }
@@ -63,4 +69,21 @@ func TestGRPCServer(t *testing.T) {
 			t.Fatalf("Got unexpected response %v", rsp.Msg)
 		}
 	}
+
+	// Test grpc error
+	rsp := pb.Response{}
+
+	if err := cc.Invoke(context.Background(), "/test.Test/Call", &pb.Request{Name: "Error"}, &rsp); err != nil {
+		st, ok := status.FromError(err)
+		if !ok {
+			t.Fatalf("invalid error received %#+v\n", err)
+		}
+		verr, ok := st.Details()[0].(*errors.Error)
+		if !ok {
+			t.Fatalf("invalid error received %#+v\n", st.Details()[0])
+		}
+		if verr.Code != 99 && verr.Id != "1" && verr.Detail != "detail" {
+			t.Fatalf("invalid error received %#+v\n", verr)
+		}
+	}
 }