protovalidate: Add custom ErrorConverter

interceptors/protovalidate/example_stream_test.go

@@ -10,6 +10,8 @@ import (
 	protovalidate_middleware "github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/protovalidate"
 	testvalidatev1 "github.com/grpc-ecosystem/go-grpc-middleware/v2/testing/testvalidate/v1"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 type StreamService struct {
@@ -32,7 +34,13 @@ func ExampleStreamServerInterceptor() {
 				protovalidate_middleware.StreamServerInterceptor(validator,
 					protovalidate_middleware.WithIgnoreMessages(
 						(&testvalidatev1.SendStreamRequest{}).ProtoReflect().Type(),
-					)),
+					),
+					protovalidate_middleware.WithErrorConverter(
+						func(err error) error {
+							return status.Error(codes.InvalidArgument, err.Error())
+						},
+					),
+				),
 			),
 		)
 		svc = &StreamService{}

interceptors/protovalidate/example_unary_test.go

@@ -11,6 +11,8 @@ import (
 	protovalidate_middleware "github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/protovalidate"
 	testvalidatev1 "github.com/grpc-ecosystem/go-grpc-middleware/v2/testing/testvalidate/v1"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 type UnaryService struct {
@@ -34,6 +36,11 @@ func ExampleUnaryServerInterceptor() {
 					protovalidate_middleware.WithIgnoreMessages(
 						(&testvalidatev1.SendRequest{}).ProtoReflect().Type(),
 					),
+					protovalidate_middleware.WithErrorConverter(
+						func(err error) error {
+							return status.Error(codes.InvalidArgument, err.Error())
+						},
+					),
 				),
 			),
 		)

interceptors/protovalidate/options.go

@@ -8,18 +8,33 @@ package protovalidate
 
 import (
 	"golang.org/x/exp/slices"
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
+// DefaultErrorConverter returns InvalidArgument status with error message from validator.
+func DefaultErrorConverter(err error) error {
+	return status.Error(codes.InvalidArgument, err.Error())
+}
+
+var (
+	defaultOptions = &options{
+		errorConverter: DefaultErrorConverter,
+	}
+)
+
 type options struct {
 	ignoreMessages []protoreflect.MessageType
+	errorConverter ErrorConverter
 }
 
 // An Option lets you add options to protovalidate interceptors using With* funcs.
 type Option func(*options)
 
 func evaluateOpts(opts []Option) *options {
 	optCopy := &options{}
+	*optCopy = *defaultOptions
 	for _, o := range opts {
 		o(optCopy)
 	}
@@ -39,3 +54,15 @@ func (o *options) shouldIgnoreMessage(m protoreflect.MessageType) bool {
 		return m == t
 	})
 }
+
+// ErrorConverter function customize the error returned by protovalidate.Validator.
+type ErrorConverter = func(err error) error
+
+// WithErrorConverter customizes the function for mapping errors.
+//
+// By default, DefaultErrorConverter used.
+func WithErrorConverter(errorConverter ErrorConverter) Option {
+	return func(o *options) {
+		o.errorConverter = errorConverter
+	}
+}

interceptors/protovalidate/protovalidate.go

@@ -5,34 +5,38 @@ package protovalidate
 
 import (
 	"context"
-	"errors"
 
 	"github.com/bufbuild/protovalidate-go"
 	"google.golang.org/grpc"
-	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/status"
 	"google.golang.org/protobuf/proto"
 )
 
+func validateMessage(validator *protovalidate.Validator, o *options, req any) error {
+	msg := req.(proto.Message)
+
+	if o.shouldIgnoreMessage(msg.ProtoReflect().Type()) {
+		return nil
+	}
+
+	if err := validator.Validate(msg); err != nil {
+		return o.errorConverter(err)
+	}
+
+	return nil
+}
+
 // UnaryServerInterceptor returns a new unary server interceptor that validates incoming messages.
 func UnaryServerInterceptor(validator *protovalidate.Validator, opts ...Option) grpc.UnaryServerInterceptor {
+	o := evaluateOpts(opts)
+
 	return func(
 		ctx context.Context,
 		req interface{},
 		info *grpc.UnaryServerInfo,
 		handler grpc.UnaryHandler,
 	) (resp interface{}, err error) {
-		o := evaluateOpts(opts)
-		switch msg := req.(type) {
-		case proto.Message:
-			if o.shouldIgnoreMessage(msg.ProtoReflect().Type()) {
-				break
-			}
-			if err = validator.Validate(msg); err != nil {
-				return nil, status.Error(codes.InvalidArgument, err.Error())
-			}
-		default:
-			return nil, errors.New("unsupported message type")
+		if err := validateMessage(validator, o, req); err != nil {
+			return nil, err
 		}
 
 		return handler(ctx, req)
@@ -41,55 +45,40 @@ func UnaryServerInterceptor(validator *protovalidate.Validator, opts ...Option)
 
 // StreamServerInterceptor returns a new streaming server interceptor that validates incoming messages.
 func StreamServerInterceptor(validator *protovalidate.Validator, opts ...Option) grpc.StreamServerInterceptor {
+	o := evaluateOpts(opts)
+
 	return func(
 		srv interface{},
 		stream grpc.ServerStream,
 		info *grpc.StreamServerInfo,
 		handler grpc.StreamHandler,
 	) error {
-		ctx := stream.Context()
-
-		wrapped := wrapServerStream(stream)
-		wrapped.wrappedContext = ctx
-		wrapped.validator = validator
-		wrapped.options = evaluateOpts(opts)
+		wrapped := wrapServerStream(stream, validator, o)
 
 		return handler(srv, wrapped)
 	}
 }
 
 func (w *wrappedServerStream) RecvMsg(m interface{}) error {
-	if err := w.ServerStream.RecvMsg(m); err != nil {
+	if err := validateMessage(w.validator, w.options, m); err != nil {
 		return err
 	}
 
-	msg := m.(proto.Message)
-	if w.options.shouldIgnoreMessage(msg.ProtoReflect().Type()) {
-		return nil
-	}
-	if err := w.validator.Validate(msg); err != nil {
-		return status.Error(codes.InvalidArgument, err.Error())
-	}
-
-	return nil
+	return w.ServerStream.RecvMsg(m)
 }
 
-// wrappedServerStream is a thin wrapper around grpc.ServerStream that allows modifying context.
+// wrappedServerStream is a thin wrapper around grpc.ServerStream that allows to validate messages.
 type wrappedServerStream struct {
 	grpc.ServerStream
-	// wrappedContext is the wrapper's own Context. You can assign it.
-	wrappedContext context.Context
-
 	validator *protovalidate.Validator
 	options   *options
 }
 
-// Context returns the wrapper's WrappedContext, overwriting the nested grpc.ServerStream.Context()
-func (w *wrappedServerStream) Context() context.Context {
-	return w.wrappedContext
-}
-
-// wrapServerStream returns a ServerStream that has the ability to overwrite context.
-func wrapServerStream(stream grpc.ServerStream) *wrappedServerStream {
-	return &wrappedServerStream{ServerStream: stream, wrappedContext: stream.Context()}
+// wrapServerStream returns a ServerStream that has the ability to validate messages.
+func wrapServerStream(
+	stream grpc.ServerStream,
+	validator *protovalidate.Validator,
+	options *options,
+) *wrappedServerStream {
+	return &wrappedServerStream{ServerStream: stream, validator: validator, options: options}
 }

interceptors/protovalidate/protovalidate_test.go

@@ -5,6 +5,7 @@ package protovalidate_test
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"net"
 	"testing"
@@ -19,12 +20,15 @@ import (
 	"google.golang.org/grpc/credentials/insecure"
 	"google.golang.org/grpc/status"
 	"google.golang.org/grpc/test/bufconn"
-	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
+func customErrorConverter(err error) error {
+	return fmt.Errorf("my custom wrapper: %w", err)
+}
+
 func TestUnaryServerInterceptor(t *testing.T) {
 	validator, err := protovalidate.New()
-	assert.Nil(t, err)
+	assert.NoError(t, err)
 
 	interceptor := protovalidate_middleware.UnaryServerInterceptor(validator)
 
@@ -38,7 +42,7 @@ func TestUnaryServerInterceptor(t *testing.T) {
 		}
 
 		resp, err := interceptor(context.TODO(), testvalidate.GoodUnaryRequest, info, handler)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 		assert.Equal(t, resp, "good")
 	})
 
@@ -62,9 +66,24 @@ func TestUnaryServerInterceptor(t *testing.T) {
 		}
 
 		resp, err := interceptor(context.TODO(), testvalidate.BadUnaryRequest, info, handler)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 		assert.Equal(t, resp, "good")
 	})
+
+	interceptor = protovalidate_middleware.UnaryServerInterceptor(validator,
+		protovalidate_middleware.WithErrorConverter(customErrorConverter),
+	)
+
+	t.Run("custom_error_converter", func(t *testing.T) {
+		info := &grpc.UnaryServerInfo{
+			FullMethod: "FakeMethod",
+		}
+
+		_, err = interceptor(context.TODO(), testvalidate.BadUnaryRequest, info, handler)
+		assert.Error(t, err)
+		assert.Equal(t, codes.Unknown, status.Code(err))
+		assert.EqualError(t, err, "my custom wrapper: validation error:\n - message: value must be a valid email address [string.email]")
+	})
 }
 
 type server struct {
@@ -84,17 +103,15 @@ func (g *server) SendStream(
 
 const bufSize = 1024 * 1024
 
-func startGrpcServer(t *testing.T, ignoreMessages ...protoreflect.MessageType) *grpc.ClientConn {
+func startGrpcServer(t *testing.T, opts ...protovalidate_middleware.Option) *grpc.ClientConn {
 	lis := bufconn.Listen(bufSize)
 
 	validator, err := protovalidate.New()
 	assert.Nil(t, err)
 
 	s := grpc.NewServer(
 		grpc.StreamInterceptor(
-			protovalidate_middleware.StreamServerInterceptor(validator,
-				protovalidate_middleware.WithIgnoreMessages(ignoreMessages...),
-			),
+			protovalidate_middleware.StreamServerInterceptor(validator, opts...),
 		),
 	)
 	testvalidatev1.RegisterTestValidateServiceServer(s, &server{})
@@ -133,7 +150,7 @@ func TestStreamServerInterceptor(t *testing.T) {
 		)
 
 		_, err := client.SendStream(context.Background(), testvalidate.GoodStreamRequest)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 	})
 
 	t.Run("invalid_email", func(t *testing.T) {
@@ -151,13 +168,31 @@ func TestStreamServerInterceptor(t *testing.T) {
 
 	t.Run("invalid_email_ignored", func(t *testing.T) {
 		client := testvalidatev1.NewTestValidateServiceClient(
-			startGrpcServer(t, testvalidate.BadStreamRequest.ProtoReflect().Type()),
+			startGrpcServer(
+				t,
+				protovalidate_middleware.WithIgnoreMessages(testvalidate.BadStreamRequest.ProtoReflect().Type()),
+			),
 		)
 
 		out, err := client.SendStream(context.Background(), testvalidate.BadStreamRequest)
-		assert.Nil(t, err)
+		assert.NoError(t, err)
 
 		_, err = out.Recv()
-		assert.Nil(t, err)
+		assert.NoError(t, err)
+	})
+
+	t.Run("custom_error_converter", func(t *testing.T) {
+		client := testvalidatev1.NewTestValidateServiceClient(
+			startGrpcServer(t, protovalidate_middleware.WithErrorConverter(customErrorConverter)),
+		)
+
+		out, err := client.SendStream(context.Background(), testvalidate.BadStreamRequest)
+		assert.NoError(t, err)
+
+		_, err = out.Recv()
+		assert.Error(t, err)
+		st, _ := status.FromError(err)
+		assert.Equal(t, codes.Unknown, st.Code())
+		assert.Equal(t, "my custom wrapper: validation error:\n - message: value must be a valid email address [string.email]", st.Message())
 	})
 }