status: handle wrapped errors

status/status.go

@@ -88,9 +88,8 @@ func FromError(err error) (s *Status, ok bool) {
 	if err == nil {
 		return nil, true
 	}
-	if se, ok := err.(interface {
-		GRPCStatus() *Status
-	}); ok {
+	var se interface{ GRPCStatus() *Status }
+	if errors.As(err, &se) {
 		return se.GRPCStatus(), true
 	}
 	return New(codes.Unknown, err.Error()), false
@@ -110,12 +109,8 @@ func Code(err error) codes.Code {
 	if err == nil {
 		return codes.OK
 	}
-	if se, ok := err.(interface {
-		GRPCStatus() *Status
-	}); ok {
-		return se.GRPCStatus().Code()
-	}
-	return codes.Unknown
+
+	return Convert(err).Code()
 }
 
 // FromContextError converts a context error or wrapped context error into a

status/status_test.go

@@ -32,6 +32,7 @@ import (
 	cpb "google.golang.org/genproto/googleapis/rpc/code"
 	epb "google.golang.org/genproto/googleapis/rpc/errdetails"
 	spb "google.golang.org/genproto/googleapis/rpc/status"
+
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/internal/grpctest"
 	"google.golang.org/grpc/internal/status"
@@ -144,6 +145,37 @@ func (s) TestFromErrorOK(t *testing.T) {
 	}
 }
 
+func (s) TestFromErrorWrapped(t *testing.T) {
+	code, message := codes.Internal, "test description"
+	err := fmt.Errorf("wrapped error: %w", Error(code, message))
+	s, ok := FromError(err)
+	if !ok || s.Code() != code || s.Message() != message || s.Err() == nil {
+		t.Fatalf("FromError(%v) = %v, %v; want <Code()=%s, Message()=%q, Err()!=nil>, true", err, s, ok, code, message)
+	}
+}
+
+func (s) TestCode(t *testing.T) {
+	code, message := codes.Internal, "test description"
+	err := Error(code, message)
+	if s := Code(err); s != code {
+		t.Fatalf("Code(%v) = %v; want <Code()=%s>", err, s, code)
+	}
+}
+
+func (s) TestCodeOK(t *testing.T) {
+	if s, code := Code(nil), codes.OK; s != code {
+		t.Fatalf("Code(%v) = %v; want <Code()=%s>", nil, s, code)
+	}
+}
+
+func (s) TestCodeWrapped(t *testing.T) {
+	code, message := codes.Internal, "test description"
+	err := fmt.Errorf("wrapped: %w", Error(code, message))
+	if s := Code(err); s != code {
+		t.Fatalf("Code(%v) = %v; want <Code()=%s>", err, s, code)
+	}
+}
+
 type customError struct {
 	Code    codes.Code
 	Message string