From a5a238d55473f1944658e9d0cf6d81fd0b213d32 Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Thu, 6 Feb 2020 13:18:33 +0300
Subject: [PATCH] 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>
---
 error.go     | 16 ++++++++++------
 grpc_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/error.go b/error.go
index 07a31c7..b625d1d 100644
--- a/error.go
+++ b/error.go
@@ -12,17 +12,21 @@ func microError(err error) error {
 		return nil
 	}
 
-	// micro error
-	if v, ok := err.(*errors.Error); ok {
-		return v
+	if verr, ok := err.(*errors.Error); ok {
+		return verr
 	}
 
 	// grpc error
 	if s, ok := status.FromError(err); ok {
-		if e := errors.Parse(s.Message()); e.Code > 0 {
-			return e // actually a micro error
+		details := s.Details()
+		if len(details) == 0 {
+			if e := errors.Parse(s.Message()); e.Code > 0 {
+				return e // actually a micro error
+			}
+			return errors.InternalServerError("go.micro.client", s.Message())
 		}
-		return errors.InternalServerError("go.micro.client", s.Message())
+		// return first error from details
+		return details[0].(error)
 	}
 
 	// do nothing
diff --git a/grpc_test.go b/grpc_test.go
index 16d34e7..1b37dad 100644
--- a/grpc_test.go
+++ b/grpc_test.go
@@ -7,6 +7,7 @@ import (
 
 	"github.com/micro/go-micro/v2/client"
 	"github.com/micro/go-micro/v2/client/selector"
+	"github.com/micro/go-micro/v2/errors"
 	"github.com/micro/go-micro/v2/registry"
 	"github.com/micro/go-micro/v2/registry/memory"
 	pgrpc "google.golang.org/grpc"
@@ -18,6 +19,9 @@ type greeterServer struct{}
 
 // SayHello implements helloworld.GreeterServer
 func (g *greeterServer) SayHello(ctx context.Context, in *pb.HelloRequest) (*pb.HelloReply, error) {
+	if in.Name == "Error" {
+		return nil, &errors.Error{Id: "1", Code: 99, Detail: "detail"}
+	}
 	return &pb.HelloReply{Message: "Hello " + in.Name}, nil
 }
 
@@ -84,4 +88,25 @@ func TestGRPCClient(t *testing.T) {
 			t.Fatalf("Got unexpected response %v", rsp.Message)
 		}
 	}
+
+	req := c.NewRequest("helloworld", "/helloworld.Greeter/SayHello", &pb.HelloRequest{
+		Name: "Error",
+	})
+
+	rsp := pb.HelloReply{}
+
+	err = c.Call(context.TODO(), req, &rsp)
+	if err == nil {
+		t.Fatal("nil error received")
+	}
+
+	verr, ok := err.(*errors.Error)
+	if !ok {
+		t.Fatalf("invalid error received %#+v\n", err)
+	}
+
+	if verr.Code != 99 && verr.Id != "1" && verr.Detail != "detail" {
+		t.Fatalf("invalid error received %#+v\n", verr)
+	}
+
 }