Add grpc methods to errdefs

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

errdefs/grpc.go

@@ -4,7 +4,6 @@ import (
 	"strings"
 
 	"github.com/pkg/errors"
-	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -61,7 +60,7 @@ func FromGRPC(err error) error {
 
 	var cls error // divide these into error classes, becomes the cause
 
-	switch grpc.Code(err) {
+	switch code(err) {
 	case codes.InvalidArgument:
 		cls = ErrInvalidArgument
 	case codes.AlreadyExists:
@@ -94,7 +93,7 @@ func FromGRPC(err error) error {
 // Effectively, we just remove the string of cls from the end of err if it
 // appears there.
 func rebaseMessage(cls error, err error) string {
-	desc := grpc.ErrorDesc(err)
+	desc := errDesc(err)
 	clss := cls.Error()
 	if desc == clss {
 		return ""
@@ -107,3 +106,17 @@ func isGRPCError(err error) bool {
 	_, ok := status.FromError(err)
 	return ok
 }
+
+func code(err error) codes.Code {
+	if s, ok := status.FromError(err); ok {
+		return s.Code()
+	}
+	return codes.Unknown
+}
+
+func errDesc(err error) string {
+	if s, ok := status.FromError(err); ok {
+		return s.Message()
+	}
+	return err.Error()
+}