From 5131c1f0966401e7074ebe74336ce41aedfee0a6 Mon Sep 17 00:00:00 2001
From: Menghan Li <menghanl@google.com>
Date: Thu, 12 Oct 2017 14:05:19 -0700
Subject: [PATCH] Use proto3 in interop tests and end2end tests (#1574)

---
 interop/grpc_testing/test.pb.go        | 196 +++++++++++-------------
 interop/grpc_testing/test.proto        |  44 +++---
 interop/http2/negative_http2_client.go |   5 +-
 interop/test_utils.go                  |  82 +++++-----
 test/codec_perf/perf.pb.go             |   8 +-
 test/codec_perf/perf.proto             |   4 +-
 test/end2end_test.go                   | 200 ++++++++++++-------------
 test/grpc_testing/test.pb.go           | 172 ++++++++++-----------
 test/grpc_testing/test.proto           |  36 ++---
 9 files changed, 351 insertions(+), 396 deletions(-)

diff --git a/interop/grpc_testing/test.pb.go b/interop/grpc_testing/test.pb.go
index b03c728c..1e7a9abd 100644
--- a/interop/grpc_testing/test.pb.go
+++ b/interop/grpc_testing/test.pb.go
@@ -64,26 +64,12 @@ var PayloadType_value = map[string]int32{
 	"RANDOM":         2,
 }
 
-func (x PayloadType) Enum() *PayloadType {
-	p := new(PayloadType)
-	*p = x
-	return p
-}
 func (x PayloadType) String() string {
 	return proto.EnumName(PayloadType_name, int32(x))
 }
-func (x *PayloadType) UnmarshalJSON(data []byte) error {
-	value, err := proto.UnmarshalJSONEnum(PayloadType_value, data, "PayloadType")
-	if err != nil {
-		return err
-	}
-	*x = PayloadType(value)
-	return nil
-}
 func (PayloadType) EnumDescriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
 
 type Empty struct {
-	XXX_unrecognized []byte `json:"-"`
 }
 
 func (m *Empty) Reset()                    { *m = Empty{} }
@@ -94,10 +80,9 @@ func (*Empty) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
 // A block of data, to simply increase gRPC message size.
 type Payload struct {
 	// The type of data in body.
-	Type *PayloadType `protobuf:"varint,1,opt,name=type,enum=grpc.testing.PayloadType" json:"type,omitempty"`
+	Type PayloadType `protobuf:"varint,1,opt,name=type,enum=grpc.testing.PayloadType" json:"type,omitempty"`
 	// Primary contents of payload.
-	Body             []byte `protobuf:"bytes,2,opt,name=body" json:"body,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	Body []byte `protobuf:"bytes,2,opt,name=body,proto3" json:"body,omitempty"`
 }
 
 func (m *Payload) Reset()                    { *m = Payload{} }
@@ -106,8 +91,8 @@ func (*Payload) ProtoMessage()               {}
 func (*Payload) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
 
 func (m *Payload) GetType() PayloadType {
-	if m != nil && m.Type != nil {
-		return *m.Type
+	if m != nil {
+		return m.Type
 	}
 	return PayloadType_COMPRESSABLE
 }
@@ -122,9 +107,8 @@ func (m *Payload) GetBody() []byte {
 // A protobuf representation for grpc status. This is used by test
 // clients to specify a status that the server should attempt to return.
 type EchoStatus struct {
-	Code             *int32  `protobuf:"varint,1,opt,name=code" json:"code,omitempty"`
-	Message          *string `protobuf:"bytes,2,opt,name=message" json:"message,omitempty"`
-	XXX_unrecognized []byte  `json:"-"`
+	Code    int32  `protobuf:"varint,1,opt,name=code" json:"code,omitempty"`
+	Message string `protobuf:"bytes,2,opt,name=message" json:"message,omitempty"`
 }
 
 func (m *EchoStatus) Reset()                    { *m = EchoStatus{} }
@@ -133,15 +117,15 @@ func (*EchoStatus) ProtoMessage()               {}
 func (*EchoStatus) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{2} }
 
 func (m *EchoStatus) GetCode() int32 {
-	if m != nil && m.Code != nil {
-		return *m.Code
+	if m != nil {
+		return m.Code
 	}
 	return 0
 }
 
 func (m *EchoStatus) GetMessage() string {
-	if m != nil && m.Message != nil {
-		return *m.Message
+	if m != nil {
+		return m.Message
 	}
 	return ""
 }
@@ -150,19 +134,18 @@ func (m *EchoStatus) GetMessage() string {
 type SimpleRequest struct {
 	// Desired payload type in the response from the server.
 	// If response_type is RANDOM, server randomly chooses one from other formats.
-	ResponseType *PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
+	ResponseType PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
 	// Desired payload size in the response from the server.
 	// If response_type is COMPRESSABLE, this denotes the size before compression.
-	ResponseSize *int32 `protobuf:"varint,2,opt,name=response_size,json=responseSize" json:"response_size,omitempty"`
+	ResponseSize int32 `protobuf:"varint,2,opt,name=response_size,json=responseSize" json:"response_size,omitempty"`
 	// Optional input payload sent along with the request.
 	Payload *Payload `protobuf:"bytes,3,opt,name=payload" json:"payload,omitempty"`
 	// Whether SimpleResponse should include username.
-	FillUsername *bool `protobuf:"varint,4,opt,name=fill_username,json=fillUsername" json:"fill_username,omitempty"`
+	FillUsername bool `protobuf:"varint,4,opt,name=fill_username,json=fillUsername" json:"fill_username,omitempty"`
 	// Whether SimpleResponse should include OAuth scope.
-	FillOauthScope *bool `protobuf:"varint,5,opt,name=fill_oauth_scope,json=fillOauthScope" json:"fill_oauth_scope,omitempty"`
+	FillOauthScope bool `protobuf:"varint,5,opt,name=fill_oauth_scope,json=fillOauthScope" json:"fill_oauth_scope,omitempty"`
 	// Whether server should return a given status
-	ResponseStatus   *EchoStatus `protobuf:"bytes,7,opt,name=response_status,json=responseStatus" json:"response_status,omitempty"`
-	XXX_unrecognized []byte      `json:"-"`
+	ResponseStatus *EchoStatus `protobuf:"bytes,7,opt,name=response_status,json=responseStatus" json:"response_status,omitempty"`
 }
 
 func (m *SimpleRequest) Reset()                    { *m = SimpleRequest{} }
@@ -171,15 +154,15 @@ func (*SimpleRequest) ProtoMessage()               {}
 func (*SimpleRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{3} }
 
 func (m *SimpleRequest) GetResponseType() PayloadType {
-	if m != nil && m.ResponseType != nil {
-		return *m.ResponseType
+	if m != nil {
+		return m.ResponseType
 	}
 	return PayloadType_COMPRESSABLE
 }
 
 func (m *SimpleRequest) GetResponseSize() int32 {
-	if m != nil && m.ResponseSize != nil {
-		return *m.ResponseSize
+	if m != nil {
+		return m.ResponseSize
 	}
 	return 0
 }
@@ -192,15 +175,15 @@ func (m *SimpleRequest) GetPayload() *Payload {
 }
 
 func (m *SimpleRequest) GetFillUsername() bool {
-	if m != nil && m.FillUsername != nil {
-		return *m.FillUsername
+	if m != nil {
+		return m.FillUsername
 	}
 	return false
 }
 
 func (m *SimpleRequest) GetFillOauthScope() bool {
-	if m != nil && m.FillOauthScope != nil {
-		return *m.FillOauthScope
+	if m != nil {
+		return m.FillOauthScope
 	}
 	return false
 }
@@ -218,10 +201,9 @@ type SimpleResponse struct {
 	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 	// The user the request came from, for verifying authentication was
 	// successful when the client expected it.
-	Username *string `protobuf:"bytes,2,opt,name=username" json:"username,omitempty"`
+	Username string `protobuf:"bytes,2,opt,name=username" json:"username,omitempty"`
 	// OAuth scope.
-	OauthScope       *string `protobuf:"bytes,3,opt,name=oauth_scope,json=oauthScope" json:"oauth_scope,omitempty"`
-	XXX_unrecognized []byte  `json:"-"`
+	OauthScope string `protobuf:"bytes,3,opt,name=oauth_scope,json=oauthScope" json:"oauth_scope,omitempty"`
 }
 
 func (m *SimpleResponse) Reset()                    { *m = SimpleResponse{} }
@@ -237,15 +219,15 @@ func (m *SimpleResponse) GetPayload() *Payload {
 }
 
 func (m *SimpleResponse) GetUsername() string {
-	if m != nil && m.Username != nil {
-		return *m.Username
+	if m != nil {
+		return m.Username
 	}
 	return ""
 }
 
 func (m *SimpleResponse) GetOauthScope() string {
-	if m != nil && m.OauthScope != nil {
-		return *m.OauthScope
+	if m != nil {
+		return m.OauthScope
 	}
 	return ""
 }
@@ -253,8 +235,7 @@ func (m *SimpleResponse) GetOauthScope() string {
 // Client-streaming request.
 type StreamingInputCallRequest struct {
 	// Optional input payload sent along with the request.
-	Payload          *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
-	XXX_unrecognized []byte   `json:"-"`
+	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 }
 
 func (m *StreamingInputCallRequest) Reset()                    { *m = StreamingInputCallRequest{} }
@@ -272,8 +253,7 @@ func (m *StreamingInputCallRequest) GetPayload() *Payload {
 // Client-streaming response.
 type StreamingInputCallResponse struct {
 	// Aggregated size of payloads received from the client.
-	AggregatedPayloadSize *int32 `protobuf:"varint,1,opt,name=aggregated_payload_size,json=aggregatedPayloadSize" json:"aggregated_payload_size,omitempty"`
-	XXX_unrecognized      []byte `json:"-"`
+	AggregatedPayloadSize int32 `protobuf:"varint,1,opt,name=aggregated_payload_size,json=aggregatedPayloadSize" json:"aggregated_payload_size,omitempty"`
 }
 
 func (m *StreamingInputCallResponse) Reset()                    { *m = StreamingInputCallResponse{} }
@@ -282,8 +262,8 @@ func (*StreamingInputCallResponse) ProtoMessage()               {}
 func (*StreamingInputCallResponse) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{6} }
 
 func (m *StreamingInputCallResponse) GetAggregatedPayloadSize() int32 {
-	if m != nil && m.AggregatedPayloadSize != nil {
-		return *m.AggregatedPayloadSize
+	if m != nil {
+		return m.AggregatedPayloadSize
 	}
 	return 0
 }
@@ -292,11 +272,10 @@ func (m *StreamingInputCallResponse) GetAggregatedPayloadSize() int32 {
 type ResponseParameters struct {
 	// Desired payload sizes in responses from the server.
 	// If response_type is COMPRESSABLE, this denotes the size before compression.
-	Size *int32 `protobuf:"varint,1,opt,name=size" json:"size,omitempty"`
+	Size int32 `protobuf:"varint,1,opt,name=size" json:"size,omitempty"`
 	// Desired interval between consecutive responses in the response stream in
 	// microseconds.
-	IntervalUs       *int32 `protobuf:"varint,2,opt,name=interval_us,json=intervalUs" json:"interval_us,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	IntervalUs int32 `protobuf:"varint,2,opt,name=interval_us,json=intervalUs" json:"interval_us,omitempty"`
 }
 
 func (m *ResponseParameters) Reset()                    { *m = ResponseParameters{} }
@@ -305,15 +284,15 @@ func (*ResponseParameters) ProtoMessage()               {}
 func (*ResponseParameters) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{7} }
 
 func (m *ResponseParameters) GetSize() int32 {
-	if m != nil && m.Size != nil {
-		return *m.Size
+	if m != nil {
+		return m.Size
 	}
 	return 0
 }
 
 func (m *ResponseParameters) GetIntervalUs() int32 {
-	if m != nil && m.IntervalUs != nil {
-		return *m.IntervalUs
+	if m != nil {
+		return m.IntervalUs
 	}
 	return 0
 }
@@ -324,14 +303,13 @@ type StreamingOutputCallRequest struct {
 	// If response_type is RANDOM, the payload from each response in the stream
 	// might be of different types. This is to simulate a mixed type of payload
 	// stream.
-	ResponseType *PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
+	ResponseType PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
 	// Configuration for each expected response message.
 	ResponseParameters []*ResponseParameters `protobuf:"bytes,2,rep,name=response_parameters,json=responseParameters" json:"response_parameters,omitempty"`
 	// Optional input payload sent along with the request.
 	Payload *Payload `protobuf:"bytes,3,opt,name=payload" json:"payload,omitempty"`
 	// Whether server should return a given status
-	ResponseStatus   *EchoStatus `protobuf:"bytes,7,opt,name=response_status,json=responseStatus" json:"response_status,omitempty"`
-	XXX_unrecognized []byte      `json:"-"`
+	ResponseStatus *EchoStatus `protobuf:"bytes,7,opt,name=response_status,json=responseStatus" json:"response_status,omitempty"`
 }
 
 func (m *StreamingOutputCallRequest) Reset()                    { *m = StreamingOutputCallRequest{} }
@@ -340,8 +318,8 @@ func (*StreamingOutputCallRequest) ProtoMessage()               {}
 func (*StreamingOutputCallRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{8} }
 
 func (m *StreamingOutputCallRequest) GetResponseType() PayloadType {
-	if m != nil && m.ResponseType != nil {
-		return *m.ResponseType
+	if m != nil {
+		return m.ResponseType
 	}
 	return PayloadType_COMPRESSABLE
 }
@@ -370,8 +348,7 @@ func (m *StreamingOutputCallRequest) GetResponseStatus() *EchoStatus {
 // Server-streaming response, as configured by the request and parameters.
 type StreamingOutputCallResponse struct {
 	// Payload to increase response size.
-	Payload          *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
-	XXX_unrecognized []byte   `json:"-"`
+	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 }
 
 func (m *StreamingOutputCallResponse) Reset()                    { *m = StreamingOutputCallResponse{} }
@@ -860,46 +837,47 @@ var _UnimplementedService_serviceDesc = grpc.ServiceDesc{
 func init() { proto.RegisterFile("grpc_testing/test.proto", fileDescriptor0) }
 
 var fileDescriptor0 = []byte{
-	// 656 bytes of a gzipped FileDescriptorProto
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+	// 664 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xbc, 0x55, 0xdd, 0x6e, 0xd3, 0x4c,
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+	0x3b, 0x67, 0xe6, 0xd8, 0x81, 0x4d, 0x3b, 0x0a, 0x87, 0x03, 0x8e, 0x8c, 0x3b, 0xbe, 0xbd, 0x23,
+	0x7e, 0xdb, 0x61, 0x14, 0xf0, 0x80, 0xd4, 0x45, 0xa0, 0x9d, 0x06, 0xf4, 0x2a, 0x54, 0xba, 0x5e,
+	0xc8, 0xc7, 0xfa, 0x11, 0x54, 0x4f, 0xe9, 0xd8, 0x0d, 0xe8, 0x88, 0x3c, 0x83, 0x32, 0x1f, 0x87,
+	0xa8, 0x29, 0x2d, 0xc5, 0x50, 0x3b, 0x5b, 0xed, 0x7c, 0x42, 0x3b, 0x25, 0x9d, 0x8d, 0x43, 0x34,
+	0x25, 0x8d, 0x10, 0x28, 0x9f, 0x07, 0xa3, 0xb1, 0x56, 0x6a, 0x29, 0x46, 0xdd, 0x94, 0xcf, 0xfa,
+	0x6b, 0x80, 0xee, 0xf0, 0x32, 0xb0, 0x38, 0xe5, 0x31, 0x13, 0x8c, 0x61, 0x30, 0x4a, 0x0a, 0x56,
+	0x4c, 0xf9, 0x4c, 0x34, 0xa8, 0x7a, 0xc8, 0x18, 0xb5, 0x51, 0x26, 0xae, 0x9a, 0xd9, 0x51, 0xff,
+	0x56, 0x82, 0x35, 0xcb, 0xf1, 0x42, 0x17, 0x4d, 0xfc, 0x14, 0x23, 0xe3, 0xe4, 0x2d, 0xac, 0x45,
+	0xc8, 0xc2, 0xc0, 0x67, 0x38, 0xb8, 0x5b, 0x67, 0xf5, 0x8c, 0x2f, 0x4e, 0xe4, 0x51, 0x2e, 0x9f,
+	0x39, 0xd7, 0xc9, 0x8d, 0x95, 0x29, 0xc9, 0x72, 0xae, 0x91, 0xec, 0x40, 0x35, 0x4c, 0x2a, 0x68,
+	0x4b, 0x2d, 0xc5, 0xa8, 0x75, 0x36, 0x0a, 0xcb, 0x9b, 0x19, 0x4b, 0x54, 0xbd, 0x70, 0x5c, 0x77,
+	0x10, 0x33, 0x8c, 0x7c, 0xea, 0xa1, 0x56, 0x6e, 0x29, 0xc6, 0x8a, 0x59, 0x17, 0x60, 0x3f, 0xc5,
+	0x88, 0x01, 0x0d, 0x49, 0x0a, 0x68, 0xcc, 0x2f, 0x07, 0x6c, 0x18, 0x84, 0xa8, 0x55, 0x24, 0x4f,
+	0x15, 0x78, 0x4f, 0xc0, 0x96, 0x40, 0xc9, 0x2e, 0xfc, 0x3f, 0x6d, 0x52, 0xce, 0x4d, 0xab, 0xca,
+	0x3e, 0xb4, 0xd9, 0x3e, 0xa6, 0x73, 0x35, 0xd5, 0x89, 0x00, 0x79, 0xd6, 0xbf, 0x80, 0x9a, 0x0d,
+	0x2e, 0xc1, 0xf3, 0xa2, 0x94, 0x3b, 0x89, 0x6a, 0xc2, 0xca, 0x44, 0x4f, 0xb2, 0x97, 0xc9, 0x99,
+	0x3c, 0x84, 0x5a, 0x5e, 0xc6, 0x92, 0x0c, 0x43, 0x30, 0x91, 0xa0, 0x1f, 0xc1, 0x96, 0xc5, 0x23,
+	0xa4, 0x9e, 0xe3, 0xdb, 0x87, 0x7e, 0x18, 0xf3, 0x3d, 0xea, 0xba, 0xd9, 0x12, 0x17, 0x6d, 0x45,
+	0x3f, 0x83, 0x66, 0x51, 0xb5, 0x54, 0xd9, 0x2b, 0xd8, 0xa4, 0xb6, 0x1d, 0xa1, 0x4d, 0x39, 0x8e,
+	0x06, 0x69, 0x4e, 0xb2, 0xdd, 0xc4, 0x66, 0x1b, 0xd3, 0x70, 0x5a, 0x5a, 0xac, 0x59, 0x3f, 0x04,
+	0x92, 0xd5, 0x38, 0xa5, 0x11, 0xf5, 0x90, 0x63, 0x24, 0x1d, 0x9a, 0x4b, 0x95, 0xcf, 0x42, 0xae,
+	0xe3, 0x73, 0x8c, 0xae, 0xa8, 0xd8, 0x71, 0xea, 0x19, 0xc8, 0xa0, 0x3e, 0xd3, 0xbf, 0x96, 0x72,
+	0x1d, 0xf6, 0x62, 0x3e, 0x27, 0xf8, 0x77, 0x5d, 0xfb, 0x11, 0xd6, 0x27, 0xf9, 0xe1, 0xa4, 0x55,
+	0xad, 0xd4, 0x5a, 0x32, 0x6a, 0x9d, 0xd6, 0x6c, 0x95, 0x9b, 0x92, 0x4c, 0x12, 0xdd, 0x94, 0xb9,
+	0xb0, 0xc7, 0xff, 0x80, 0x29, 0x4f, 0x60, 0xbb, 0x70, 0x48, 0xbf, 0xe8, 0xd0, 0xa7, 0xef, 0xa0,
+	0x96, 0x9b, 0x19, 0x69, 0x40, 0x7d, 0xaf, 0x77, 0x7c, 0x6a, 0x76, 0x2d, 0x6b, 0xf7, 0xfd, 0x51,
+	0xb7, 0xf1, 0x1f, 0x21, 0xa0, 0xf6, 0x4f, 0x66, 0x30, 0x85, 0x00, 0x2c, 0x9b, 0xbb, 0x27, 0xfb,
+	0xbd, 0xe3, 0x46, 0xa9, 0xf3, 0xbd, 0x0c, 0xb5, 0x33, 0x64, 0xdc, 0xc2, 0xe8, 0xca, 0x19, 0x22,
+	0x79, 0x09, 0xab, 0xf2, 0x13, 0x28, 0xda, 0x22, 0xeb, 0x73, 0xba, 0x44, 0xa0, 0x59, 0x04, 0x92,
+	0x03, 0x58, 0xed, 0xfb, 0x34, 0x4a, 0xd2, 0xb6, 0x67, 0x19, 0x33, 0x9f, 0xaf, 0xe6, 0x83, 0xe2,
+	0x60, 0x3a, 0x00, 0x17, 0xd6, 0x0b, 0xe6, 0x43, 0x8c, 0xb9, 0xa4, 0x5b, 0x7d, 0xd6, 0x7c, 0x72,
+	0x07, 0x66, 0x72, 0xd7, 0x73, 0x85, 0x38, 0x40, 0x6e, 0xbe, 0x54, 0xe4, 0xf1, 0x2d, 0x25, 0xe6,
+	0x5f, 0xe2, 0xa6, 0xf1, 0x73, 0x62, 0x72, 0x95, 0x21, 0xae, 0x52, 0x0f, 0x62, 0xd7, 0xdd, 0x8f,
+	0x43, 0x17, 0x3f, 0xff, 0x35, 0x4d, 0x86, 0x22, 0x55, 0xa9, 0x1f, 0xa8, 0x7b, 0xf1, 0x0f, 0xae,
+	0xea, 0xf4, 0xe1, 0x7e, 0xdf, 0x97, 0x1b, 0xf4, 0xd0, 0xe7, 0x38, 0xca, 0x5c, 0xf4, 0x06, 0xee,
+	0xcd, 0xe0, 0x8b, 0xb9, 0xe9, 0x7c, 0x59, 0xfe, 0x39, 0xbf, 0xf8, 0x11, 0x00, 0x00, 0xff, 0xff,
+	0x87, 0xd4, 0xf3, 0x98, 0xb7, 0x07, 0x00, 0x00,
 }
diff --git a/interop/grpc_testing/test.proto b/interop/grpc_testing/test.proto
index 20d4366b..f9f303db 100644
--- a/interop/grpc_testing/test.proto
+++ b/interop/grpc_testing/test.proto
@@ -14,7 +14,7 @@
 
 // An integration test service that covers all the method signature permutations
 // of unary/streaming requests/responses.
-syntax = "proto2";
+syntax = "proto3";
 
 package grpc.testing;
 
@@ -35,58 +35,58 @@ enum PayloadType {
 // A block of data, to simply increase gRPC message size.
 message Payload {
   // The type of data in body.
-  optional PayloadType type = 1;
+  PayloadType type = 1;
   // Primary contents of payload.
-  optional bytes body = 2;
+  bytes body = 2;
 }
 
 // A protobuf representation for grpc status. This is used by test
 // clients to specify a status that the server should attempt to return.
 message EchoStatus {
-  optional int32 code = 1;
-  optional string message = 2;
+  int32 code = 1;
+  string message = 2;
 }
 
 // Unary request.
 message SimpleRequest {
   // Desired payload type in the response from the server.
   // If response_type is RANDOM, server randomly chooses one from other formats.
-  optional PayloadType response_type = 1;
+  PayloadType response_type = 1;
 
   // Desired payload size in the response from the server.
   // If response_type is COMPRESSABLE, this denotes the size before compression.
-  optional int32 response_size = 2;
+  int32 response_size = 2;
 
   // Optional input payload sent along with the request.
-  optional Payload payload = 3;
+  Payload payload = 3;
 
   // Whether SimpleResponse should include username.
-  optional bool fill_username = 4;
+  bool fill_username = 4;
 
   // Whether SimpleResponse should include OAuth scope.
-  optional bool fill_oauth_scope = 5;
+  bool fill_oauth_scope = 5;
 
   // Whether server should return a given status
-  optional EchoStatus response_status = 7;
+  EchoStatus response_status = 7;
 }
 
 // Unary response, as configured by the request.
 message SimpleResponse {
   // Payload to increase message size.
-  optional Payload payload = 1;
+  Payload payload = 1;
 
   // The user the request came from, for verifying authentication was
   // successful when the client expected it.
-  optional string username = 2;
+  string username = 2;
   
   // OAuth scope.
-  optional string oauth_scope = 3;
+  string oauth_scope = 3;
 }
 
 // Client-streaming request.
 message StreamingInputCallRequest {
   // Optional input payload sent along with the request.
-  optional Payload payload = 1;
+  Payload payload = 1;
 
   // Not expecting any payload from the response.
 }
@@ -94,18 +94,18 @@ message StreamingInputCallRequest {
 // Client-streaming response.
 message StreamingInputCallResponse {
   // Aggregated size of payloads received from the client.
-  optional int32 aggregated_payload_size = 1;
+  int32 aggregated_payload_size = 1;
 }
 
 // Configuration for a particular response.
 message ResponseParameters {
   // Desired payload sizes in responses from the server.
   // If response_type is COMPRESSABLE, this denotes the size before compression.
-  optional int32 size = 1;
+  int32 size = 1;
 
   // Desired interval between consecutive responses in the response stream in
   // microseconds.
-  optional int32 interval_us = 2;
+  int32 interval_us = 2;
 }
 
 // Server-streaming request.
@@ -114,22 +114,22 @@ message StreamingOutputCallRequest {
   // If response_type is RANDOM, the payload from each response in the stream
   // might be of different types. This is to simulate a mixed type of payload
   // stream.
-  optional PayloadType response_type = 1;
+  PayloadType response_type = 1;
 
   // Configuration for each expected response message.
   repeated ResponseParameters response_parameters = 2;
 
   // Optional input payload sent along with the request.
-  optional Payload payload = 3;
+  Payload payload = 3;
 
   // Whether server should return a given status
-  optional EchoStatus response_status = 7;
+  EchoStatus response_status = 7;
 }
 
 // Server-streaming response, as configured by the request and parameters.
 message StreamingOutputCallResponse {
   // Payload to increase response size.
-  optional Payload payload = 1;
+  Payload payload = 1;
 }
 
 // A simple service to test the various types of RPCs and experiment with
diff --git a/interop/http2/negative_http2_client.go b/interop/http2/negative_http2_client.go
index 5b42b76a..8f94edd4 100644
--- a/interop/http2/negative_http2_client.go
+++ b/interop/http2/negative_http2_client.go
@@ -30,7 +30,6 @@ import (
 	"sync"
 	"time"
 
-	"github.com/golang/protobuf/proto"
 	"golang.org/x/net/context"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
@@ -57,8 +56,8 @@ var (
 func largeSimpleRequest() *testpb.SimpleRequest {
 	pl := interop.ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	return &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeRespSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeRespSize),
 		Payload:      pl,
 	}
 }
diff --git a/interop/test_utils.go b/interop/test_utils.go
index 36285d36..119c8721 100644
--- a/interop/test_utils.go
+++ b/interop/test_utils.go
@@ -61,7 +61,7 @@ func ClientNewPayload(t testpb.PayloadType, size int) *testpb.Payload {
 		grpclog.Fatalf("Unsupported payload type: %d", t)
 	}
 	return &testpb.Payload{
-		Type: t.Enum(),
+		Type: t,
 		Body: body,
 	}
 }
@@ -81,8 +81,8 @@ func DoEmptyUnaryCall(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 func DoLargeUnaryCall(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeRespSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeRespSize),
 		Payload:      pl,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req, args...)
@@ -127,11 +127,11 @@ func DoServerStreaming(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 	respParam := make([]*testpb.ResponseParameters, len(respSizes))
 	for i, s := range respSizes {
 		respParam[i] = &testpb.ResponseParameters{
-			Size: proto.Int32(int32(s)),
+			Size: int32(s),
 		}
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 	}
 	stream, err := tc.StreamingOutputCall(context.Background(), req, args...)
@@ -176,12 +176,12 @@ func DoPingPong(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 	for index < len(reqSizes) {
 		respParam := []*testpb.ResponseParameters{
 			{
-				Size: proto.Int32(int32(respSizes[index])),
+				Size: int32(respSizes[index]),
 			},
 		}
 		pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, reqSizes[index])
 		req := &testpb.StreamingOutputCallRequest{
-			ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+			ResponseType:       testpb.PayloadType_COMPRESSABLE,
 			ResponseParameters: respParam,
 			Payload:            pl,
 		}
@@ -237,7 +237,7 @@ func DoTimeoutOnSleepingServer(tc testpb.TestServiceClient, args ...grpc.CallOpt
 	}
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, 27182)
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
 		Payload:      pl,
 	}
 	if err := stream.Send(req); err != nil {
@@ -254,11 +254,11 @@ func DoTimeoutOnSleepingServer(tc testpb.TestServiceClient, args ...grpc.CallOpt
 func DoComputeEngineCreds(tc testpb.TestServiceClient, serviceAccount, oauthScope string) {
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType:   testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize:   proto.Int32(int32(largeRespSize)),
+		ResponseType:   testpb.PayloadType_COMPRESSABLE,
+		ResponseSize:   int32(largeRespSize),
 		Payload:        pl,
-		FillUsername:   proto.Bool(true),
-		FillOauthScope: proto.Bool(true),
+		FillUsername:   true,
+		FillOauthScope: true,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req)
 	if err != nil {
@@ -286,11 +286,11 @@ func getServiceAccountJSONKey(keyFile string) []byte {
 func DoServiceAccountCreds(tc testpb.TestServiceClient, serviceAccountKeyFile, oauthScope string) {
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType:   testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize:   proto.Int32(int32(largeRespSize)),
+		ResponseType:   testpb.PayloadType_COMPRESSABLE,
+		ResponseSize:   int32(largeRespSize),
 		Payload:        pl,
-		FillUsername:   proto.Bool(true),
-		FillOauthScope: proto.Bool(true),
+		FillUsername:   true,
+		FillOauthScope: true,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req)
 	if err != nil {
@@ -311,10 +311,10 @@ func DoServiceAccountCreds(tc testpb.TestServiceClient, serviceAccountKeyFile, o
 func DoJWTTokenCreds(tc testpb.TestServiceClient, serviceAccountKeyFile string) {
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeRespSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeRespSize),
 		Payload:      pl,
-		FillUsername: proto.Bool(true),
+		FillUsername: true,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req)
 	if err != nil {
@@ -345,11 +345,11 @@ func GetToken(serviceAccountKeyFile string, oauthScope string) *oauth2.Token {
 func DoOauth2TokenCreds(tc testpb.TestServiceClient, serviceAccountKeyFile, oauthScope string) {
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType:   testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize:   proto.Int32(int32(largeRespSize)),
+		ResponseType:   testpb.PayloadType_COMPRESSABLE,
+		ResponseSize:   int32(largeRespSize),
 		Payload:        pl,
-		FillUsername:   proto.Bool(true),
-		FillOauthScope: proto.Bool(true),
+		FillUsername:   true,
+		FillOauthScope: true,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req)
 	if err != nil {
@@ -371,11 +371,11 @@ func DoPerRPCCreds(tc testpb.TestServiceClient, serviceAccountKeyFile, oauthScop
 	jsonKey := getServiceAccountJSONKey(serviceAccountKeyFile)
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, largeReqSize)
 	req := &testpb.SimpleRequest{
-		ResponseType:   testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize:   proto.Int32(int32(largeRespSize)),
+		ResponseType:   testpb.PayloadType_COMPRESSABLE,
+		ResponseSize:   int32(largeRespSize),
 		Payload:        pl,
-		FillUsername:   proto.Bool(true),
-		FillOauthScope: proto.Bool(true),
+		FillUsername:   true,
+		FillOauthScope: true,
 	}
 	token := GetToken(serviceAccountKeyFile, oauthScope)
 	kv := map[string]string{"authorization": token.Type() + " " + token.AccessToken}
@@ -424,12 +424,12 @@ func DoCancelAfterFirstResponse(tc testpb.TestServiceClient, args ...grpc.CallOp
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(31415),
+			Size: 31415,
 		},
 	}
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, 27182)
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            pl,
 	}
@@ -474,8 +474,8 @@ func DoCustomMetadata(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 	// Testing with UnaryCall.
 	pl := ClientNewPayload(testpb.PayloadType_COMPRESSABLE, 1)
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(1)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(1),
 		Payload:      pl,
 	}
 	ctx := metadata.NewOutgoingContext(context.Background(), customMetadata)
@@ -503,11 +503,11 @@ func DoCustomMetadata(tc testpb.TestServiceClient, args ...grpc.CallOption) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(1),
+			Size: 1,
 		},
 	}
 	streamReq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            pl,
 	}
@@ -537,8 +537,8 @@ func DoStatusCodeAndMessage(tc testpb.TestServiceClient, args ...grpc.CallOption
 	msg := "test status message"
 	expectedErr := grpc.Errorf(codes.Code(code), msg)
 	respStatus := &testpb.EchoStatus{
-		Code:    proto.Int32(code),
-		Message: proto.String(msg),
+		Code:    code,
+		Message: msg,
 	}
 	// Test UnaryCall.
 	req := &testpb.SimpleRequest{
@@ -607,7 +607,7 @@ func serverNewPayload(t testpb.PayloadType, size int32) (*testpb.Payload, error)
 		return nil, fmt.Errorf("unsupported payload type: %d", t)
 	}
 	return &testpb.Payload{
-		Type: t.Enum(),
+		Type: t,
 		Body: body,
 	}, nil
 }
@@ -624,8 +624,8 @@ func (s *testServer) UnaryCall(ctx context.Context, in *testpb.SimpleRequest) (*
 			grpc.SetTrailer(ctx, trailer)
 		}
 	}
-	if status != nil && *status.Code != 0 {
-		return nil, grpc.Errorf(codes.Code(*status.Code), *status.Message)
+	if status != nil && status.Code != 0 {
+		return nil, grpc.Errorf(codes.Code(status.Code), status.Message)
 	}
 	pl, err := serverNewPayload(in.GetResponseType(), in.GetResponseSize())
 	if err != nil {
@@ -661,7 +661,7 @@ func (s *testServer) StreamingInputCall(stream testpb.TestService_StreamingInput
 		in, err := stream.Recv()
 		if err == io.EOF {
 			return stream.SendAndClose(&testpb.StreamingInputCallResponse{
-				AggregatedPayloadSize: proto.Int32(int32(sum)),
+				AggregatedPayloadSize: int32(sum),
 			})
 		}
 		if err != nil {
@@ -693,8 +693,8 @@ func (s *testServer) FullDuplexCall(stream testpb.TestService_FullDuplexCallServ
 			return err
 		}
 		status := in.GetResponseStatus()
-		if status != nil && *status.Code != 0 {
-			return grpc.Errorf(codes.Code(*status.Code), *status.Message)
+		if status != nil && status.Code != 0 {
+			return grpc.Errorf(codes.Code(status.Code), status.Message)
 		}
 		cs := in.GetResponseParameters()
 		for _, c := range cs {
diff --git a/test/codec_perf/perf.pb.go b/test/codec_perf/perf.pb.go
index 9401b1dd..fb6fc5d9 100644
--- a/test/codec_perf/perf.pb.go
+++ b/test/codec_perf/perf.pb.go
@@ -30,8 +30,7 @@ const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 // Buffer is a message that contains a body of bytes that is used to exercise
 // encoding and decoding overheads.
 type Buffer struct {
-	Body             []byte `protobuf:"bytes,1,opt,name=body" json:"body,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	Body []byte `protobuf:"bytes,1,opt,name=body,proto3" json:"body,omitempty"`
 }
 
 func (m *Buffer) Reset()                    { *m = Buffer{} }
@@ -53,10 +52,11 @@ func init() {
 func init() { proto.RegisterFile("codec_perf/perf.proto", fileDescriptor0) }
 
 var fileDescriptor0 = []byte{
-	// 78 bytes of a gzipped FileDescriptorProto
+	// 83 bytes of a gzipped FileDescriptorProto
 	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0x12, 0x4d, 0xce, 0x4f, 0x49,
 	0x4d, 0x8e, 0x2f, 0x48, 0x2d, 0x4a, 0xd3, 0x07, 0x11, 0x7a, 0x05, 0x45, 0xf9, 0x25, 0xf9, 0x42,
 	0x5c, 0x60, 0x61, 0x3d, 0x90, 0x88, 0x92, 0x0c, 0x17, 0x9b, 0x53, 0x69, 0x5a, 0x5a, 0x6a, 0x91,
 	0x90, 0x10, 0x17, 0x4b, 0x52, 0x7e, 0x4a, 0xa5, 0x04, 0xa3, 0x02, 0xa3, 0x06, 0x4f, 0x10, 0x98,
-	0x0d, 0x08, 0x00, 0x00, 0xff, 0xff, 0xdc, 0x93, 0x4c, 0x5f, 0x41, 0x00, 0x00, 0x00,
+	0x9d, 0xc4, 0x06, 0xd6, 0x60, 0x0c, 0x08, 0x00, 0x00, 0xff, 0xff, 0xa3, 0x5f, 0x4f, 0x3c, 0x49,
+	0x00, 0x00, 0x00,
 }
diff --git a/test/codec_perf/perf.proto b/test/codec_perf/perf.proto
index f42dbcaf..594c6f01 100644
--- a/test/codec_perf/perf.proto
+++ b/test/codec_perf/perf.proto
@@ -14,12 +14,12 @@
 
 // Messages used for performance tests that may not reference grpc directly for
 // reasons of import cycles.
-syntax = "proto2";
+syntax = "proto3";
 
 package codec.perf;
 
 // Buffer is a message that contains a body of bytes that is used to exercise
 // encoding and decoding overheads.
 message Buffer {
-  optional bytes body = 1;
+  bytes body = 1;
 }
diff --git a/test/end2end_test.go b/test/end2end_test.go
index ab151209..a9b83ade 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -143,7 +143,7 @@ func newPayload(t testpb.PayloadType, size int32) (*testpb.Payload, error) {
 		return nil, fmt.Errorf("Unsupported payload type: %d", t)
 	}
 	return &testpb.Payload{
-		Type: t.Enum(),
+		Type: t,
 		Body: body,
 	}, nil
 }
@@ -256,7 +256,7 @@ func (s *testServer) StreamingInputCall(stream testpb.TestService_StreamingInput
 		in, err := stream.Recv()
 		if err == io.EOF {
 			return stream.SendAndClose(&testpb.StreamingInputCallResponse{
-				AggregatedPayloadSize: proto.Int32(int32(sum)),
+				AggregatedPayloadSize: int32(sum),
 			})
 		}
 		if err != nil {
@@ -894,7 +894,7 @@ func testServerGoAwayPendingRPC(t *testing.T, e env) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(1),
+			Size: 1,
 		},
 	}
 	payload, err := newPayload(testpb.PayloadType_COMPRESSABLE, int32(100))
@@ -902,7 +902,7 @@ func testServerGoAwayPendingRPC(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -978,7 +978,7 @@ func testServerMultipleGoAwayPendingRPC(t *testing.T, e env) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(1),
+			Size: 1,
 		},
 	}
 	payload, err := newPayload(testpb.PayloadType_COMPRESSABLE, int32(100))
@@ -986,7 +986,7 @@ func testServerMultipleGoAwayPendingRPC(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -1093,7 +1093,7 @@ func testConcurrentServerStopAndGoAway(t *testing.T, e env) {
 	te.srv.Stop()
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(1),
+			Size: 1,
 		},
 	}
 	payload, err := newPayload(testpb.PayloadType_COMPRESSABLE, int32(100))
@@ -1101,7 +1101,7 @@ func testConcurrentServerStopAndGoAway(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -1456,8 +1456,8 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	tc := testpb.NewTestServiceClient(te1.clientConn())
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(extraLargeSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(extraLargeSize),
 		Payload:      smallPayload,
 	}
 	// Test for unary RPC recv.
@@ -1467,7 +1467,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 
 	// Test for unary RPC send.
 	req.Payload = extraLargePayload
-	req.ResponseSize = proto.Int32(int32(smallSize))
+	req.ResponseSize = int32(smallSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
@@ -1475,11 +1475,11 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	// Test for streaming RPC recv.
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(extraLargeSize)),
+			Size: int32(extraLargeSize),
 		},
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            smallPayload,
 	}
@@ -1495,7 +1495,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	}
 
 	// Test for streaming RPC send.
-	respParam[0].Size = proto.Int32(int32(smallSize))
+	respParam[0].Size = int32(smallSize)
 	sreq.Payload = extraLargePayload
 	stream, err = tc.FullDuplexCall(te1.ctx)
 	if err != nil {
@@ -1516,7 +1516,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 
 	// Test for unary RPC recv.
 	req.Payload = smallPayload
-	req.ResponseSize = proto.Int32(int32(largeSize))
+	req.ResponseSize = int32(largeSize)
 
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
@@ -1524,14 +1524,14 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 
 	// Test for unary RPC send.
 	req.Payload = largePayload
-	req.ResponseSize = proto.Int32(int32(smallSize))
+	req.ResponseSize = int32(smallSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
 
 	// Test for streaming RPC recv.
 	stream, err = tc.FullDuplexCall(te2.ctx)
-	respParam[0].Size = proto.Int32(int32(largeSize))
+	respParam[0].Size = int32(largeSize)
 	sreq.Payload = smallPayload
 	if err != nil {
 		t.Fatalf("%v.FullDuplexCall(_) = _, %v, want <nil>", tc, err)
@@ -1544,7 +1544,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	}
 
 	// Test for streaming RPC send.
-	respParam[0].Size = proto.Int32(int32(smallSize))
+	respParam[0].Size = int32(smallSize)
 	sreq.Payload = largePayload
 	stream, err = tc.FullDuplexCall(te2.ctx)
 	if err != nil {
@@ -1565,20 +1565,20 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 
 	// Test for unary RPC recv.
 	req.Payload = smallPayload
-	req.ResponseSize = proto.Int32(int32(largeSize))
+	req.ResponseSize = int32(largeSize)
 
 	if _, err := tc.UnaryCall(context.Background(), req); err != nil {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want <nil>", err)
 	}
 
-	req.ResponseSize = proto.Int32(int32(extraLargeSize))
+	req.ResponseSize = int32(extraLargeSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
 
 	// Test for unary RPC send.
 	req.Payload = largePayload
-	req.ResponseSize = proto.Int32(int32(smallSize))
+	req.ResponseSize = int32(smallSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err != nil {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want <nil>", err)
 	}
@@ -1593,7 +1593,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	if err != nil {
 		t.Fatalf("%v.FullDuplexCall(_) = _, %v, want <nil>", tc, err)
 	}
-	respParam[0].Size = proto.Int32(int32(largeSize))
+	respParam[0].Size = int32(largeSize)
 	sreq.Payload = smallPayload
 
 	if err := stream.Send(sreq); err != nil {
@@ -1603,7 +1603,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 		t.Fatalf("%v.Recv() = _, %v, want <nil>", stream, err)
 	}
 
-	respParam[0].Size = proto.Int32(int32(extraLargeSize))
+	respParam[0].Size = int32(extraLargeSize)
 
 	if err := stream.Send(sreq); err != nil {
 		t.Fatalf("%v.Send(%v) = %v, want <nil>", stream, sreq, err)
@@ -1613,7 +1613,7 @@ func testServiceConfigMaxMsgSize(t *testing.T, e env) {
 	}
 
 	// Test for streaming RPC send.
-	respParam[0].Size = proto.Int32(int32(smallSize))
+	respParam[0].Size = int32(smallSize)
 	sreq.Payload = largePayload
 	stream, err = tc.FullDuplexCall(te3.ctx)
 	if err != nil {
@@ -1656,8 +1656,8 @@ func testMaxMsgSizeClientDefault(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeSize),
 		Payload:      smallPayload,
 	}
 	// Test for unary RPC recv.
@@ -1667,11 +1667,11 @@ func testMaxMsgSizeClientDefault(t *testing.T, e env) {
 
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(largeSize)),
+			Size: int32(largeSize),
 		},
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            smallPayload,
 	}
@@ -1726,8 +1726,8 @@ func testMaxMsgSizeClientAPI(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeSize),
 		Payload:      smallPayload,
 	}
 	// Test for unary RPC recv.
@@ -1737,18 +1737,18 @@ func testMaxMsgSizeClientAPI(t *testing.T, e env) {
 
 	// Test for unary RPC send.
 	req.Payload = largePayload
-	req.ResponseSize = proto.Int32(int32(smallSize))
+	req.ResponseSize = int32(smallSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
 
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(largeSize)),
+			Size: int32(largeSize),
 		},
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            smallPayload,
 	}
@@ -1766,7 +1766,7 @@ func testMaxMsgSizeClientAPI(t *testing.T, e env) {
 	}
 
 	// Test for streaming RPC send.
-	respParam[0].Size = proto.Int32(int32(smallSize))
+	respParam[0].Size = int32(smallSize)
 	sreq.Payload = largePayload
 	stream, err = tc.FullDuplexCall(te.ctx)
 	if err != nil {
@@ -1812,8 +1812,8 @@ func testMaxMsgSizeServerAPI(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(int32(largeSize)),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: int32(largeSize),
 		Payload:      smallPayload,
 	}
 	// Test for unary RPC send.
@@ -1823,18 +1823,18 @@ func testMaxMsgSizeServerAPI(t *testing.T, e env) {
 
 	// Test for unary RPC recv.
 	req.Payload = largePayload
-	req.ResponseSize = proto.Int32(int32(smallSize))
+	req.ResponseSize = int32(smallSize)
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
 
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(largeSize)),
+			Size: int32(largeSize),
 		},
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            smallPayload,
 	}
@@ -1852,7 +1852,7 @@ func testMaxMsgSizeServerAPI(t *testing.T, e env) {
 	}
 
 	// Test for streaming RPC recv.
-	respParam[0].Size = proto.Int32(int32(smallSize))
+	respParam[0].Size = int32(smallSize)
 	sreq.Payload = largePayload
 	stream, err = tc.FullDuplexCall(te.ctx)
 	if err != nil {
@@ -1919,8 +1919,8 @@ func testTap(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(45),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: 45,
 		Payload:      payload,
 	}
 	if _, err := tc.UnaryCall(context.Background(), req); grpc.Code(err) != codes.Unavailable {
@@ -2173,8 +2173,8 @@ func testLargeUnary(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req)
@@ -2217,15 +2217,15 @@ func testExceedMsgLimit(t *testing.T, e env) {
 
 	// Test on server side for unary RPC.
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(smallSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: smallSize,
 		Payload:      payload,
 	}
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
 	}
 	// Test on client side for unary RPC.
-	req.ResponseSize = proto.Int32(int32(*te.maxMsgSize) + 1)
+	req.ResponseSize = int32(*te.maxMsgSize) + 1
 	req.Payload = smallPayload
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.ResourceExhausted {
 		t.Fatalf("TestService/UnaryCall(_, _) = _, %v, want _, error code: %s", err, codes.ResourceExhausted)
@@ -2238,7 +2238,7 @@ func testExceedMsgLimit(t *testing.T, e env) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(1),
+			Size: 1,
 		},
 	}
 
@@ -2248,7 +2248,7 @@ func testExceedMsgLimit(t *testing.T, e env) {
 	}
 
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            spayload,
 	}
@@ -2264,7 +2264,7 @@ func testExceedMsgLimit(t *testing.T, e env) {
 	if err != nil {
 		t.Fatalf("%v.FullDuplexCall(_) = _, %v, want <nil>", tc, err)
 	}
-	respParam[0].Size = proto.Int32(int32(*te.maxMsgSize) + 1)
+	respParam[0].Size = int32(*te.maxMsgSize) + 1
 	sreq.Payload = smallPayload
 	if err := stream.Send(sreq); err != nil {
 		t.Fatalf("%v.Send(%v) = %v, want <nil>", stream, sreq, err)
@@ -2362,7 +2362,7 @@ func testPeerFailedRPC(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
 		Payload:      largePayload,
 	}
 
@@ -2413,8 +2413,8 @@ func testMetadataUnaryRPC(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	var header, trailer metadata.MD
@@ -2459,8 +2459,8 @@ func testMultipleSetTrailerUnaryRPC(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	var trailer metadata.MD
@@ -2533,8 +2533,8 @@ func testSetAndSendHeaderUnaryRPC(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	var header metadata.MD
@@ -2576,8 +2576,8 @@ func testMultipleSetHeaderUnaryRPC(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 
@@ -2620,8 +2620,8 @@ func testMultipleSetHeaderUnaryRPCError(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	var header metadata.MD
@@ -2713,9 +2713,9 @@ func testMultipleSetHeaderStreamingRPC(t *testing.T, e env) {
 	}
 
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: []*testpb.ResponseParameters{
-			{Size: proto.Int32(respSize)},
+			{Size: respSize},
 		},
 		Payload: payload,
 	}
@@ -2777,9 +2777,9 @@ func testMultipleSetHeaderStreamingRPCError(t *testing.T, e env) {
 	}
 
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: []*testpb.ResponseParameters{
-			{Size: proto.Int32(respSize)},
+			{Size: respSize},
 		},
 		Payload: payload,
 	}
@@ -2831,8 +2831,8 @@ func testMalformedHTTP2Metadata(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(314),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: 314,
 		Payload:      payload,
 	}
 	ctx := metadata.NewOutgoingContext(context.Background(), malformedHTTP2Metadata)
@@ -2853,8 +2853,8 @@ func performOneRPC(t *testing.T, tc testpb.TestServiceClient, wg *sync.WaitGroup
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	reply, err := tc.UnaryCall(context.Background(), req, grpc.FailFast(false))
@@ -2951,8 +2951,8 @@ func testRPCTimeout(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	for i := -1; i <= 10; i++ {
@@ -2989,8 +2989,8 @@ func testCancel(t *testing.T, e env) {
 	}
 
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	ctx, cancel := context.WithCancel(context.Background())
@@ -3115,7 +3115,7 @@ func testPingPong(t *testing.T, e env) {
 	for index < len(reqSizes) {
 		respParam := []*testpb.ResponseParameters{
 			{
-				Size: proto.Int32(int32(respSizes[index])),
+				Size: int32(respSizes[index]),
 			},
 		}
 
@@ -3125,7 +3125,7 @@ func testPingPong(t *testing.T, e env) {
 		}
 
 		req := &testpb.StreamingOutputCallRequest{
-			ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+			ResponseType:       testpb.PayloadType_COMPRESSABLE,
 			ResponseParameters: respParam,
 			Payload:            payload,
 		}
@@ -3193,7 +3193,7 @@ func testMetadataStreamingRPC(t *testing.T, e env) {
 			for index := 0; index < len(reqSizes); index++ {
 				respParam := []*testpb.ResponseParameters{
 					{
-						Size: proto.Int32(int32(respSizes[index])),
+						Size: int32(respSizes[index]),
 					},
 				}
 
@@ -3203,7 +3203,7 @@ func testMetadataStreamingRPC(t *testing.T, e env) {
 				}
 
 				req := &testpb.StreamingOutputCallRequest{
-					ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+					ResponseType:       testpb.PayloadType_COMPRESSABLE,
 					ResponseParameters: respParam,
 					Payload:            payload,
 				}
@@ -3246,11 +3246,11 @@ func testServerStreaming(t *testing.T, e env) {
 	respParam := make([]*testpb.ResponseParameters, len(respSizes))
 	for i, s := range respSizes {
 		respParam[i] = &testpb.ResponseParameters{
-			Size: proto.Int32(int32(s)),
+			Size: int32(s),
 		}
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 	}
 	stream, err := tc.StreamingOutputCall(context.Background(), req)
@@ -3302,11 +3302,11 @@ func testFailedServerStreaming(t *testing.T, e env) {
 	respParam := make([]*testpb.ResponseParameters, len(respSizes))
 	for i, s := range respSizes {
 		respParam[i] = &testpb.ResponseParameters{
-			Size: proto.Int32(int32(s)),
+			Size: int32(s),
 		}
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 	}
 	ctx := metadata.NewOutgoingContext(te.ctx, testMetadata)
@@ -3647,8 +3647,8 @@ func testStreamsQuotaRecovery(t *testing.T, e env) {
 				return
 			}
 			req := &testpb.SimpleRequest{
-				ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-				ResponseSize: proto.Int32(1592),
+				ResponseType: testpb.PayloadType_COMPRESSABLE,
+				ResponseSize: 1592,
 				Payload:      payload,
 			}
 			// No rpc should go through due to the max streams limit.
@@ -3684,8 +3684,8 @@ func testCompressServerHasNoSupport(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	if _, err := tc.UnaryCall(context.Background(), req); err == nil || grpc.Code(err) != codes.Unimplemented {
@@ -3698,7 +3698,7 @@ func testCompressServerHasNoSupport(t *testing.T, e env) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(31415),
+			Size: 31415,
 		},
 	}
 	payload, err = newPayload(testpb.PayloadType_COMPRESSABLE, int32(31415))
@@ -3706,7 +3706,7 @@ func testCompressServerHasNoSupport(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -3741,8 +3741,8 @@ func testCompressOK(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.SimpleRequest{
-		ResponseType: testpb.PayloadType_COMPRESSABLE.Enum(),
-		ResponseSize: proto.Int32(respSize),
+		ResponseType: testpb.PayloadType_COMPRESSABLE,
+		ResponseSize: respSize,
 		Payload:      payload,
 	}
 	ctx := metadata.NewOutgoingContext(context.Background(), metadata.Pairs("something", "something"))
@@ -3758,7 +3758,7 @@ func testCompressOK(t *testing.T, e env) {
 	}
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(31415),
+			Size: 31415,
 		},
 	}
 	payload, err = newPayload(testpb.PayloadType_COMPRESSABLE, int32(31415))
@@ -3766,7 +3766,7 @@ func testCompressOK(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -3830,7 +3830,7 @@ func testStreamClientInterceptor(t *testing.T, e env) {
 	tc := testpb.NewTestServiceClient(te.clientConn())
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(1)),
+			Size: int32(1),
 		},
 	}
 	payload, err := newPayload(testpb.PayloadType_COMPRESSABLE, int32(1))
@@ -3838,7 +3838,7 @@ func testStreamClientInterceptor(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -3898,7 +3898,7 @@ func testStreamServerInterceptor(t *testing.T, e env) {
 	tc := testpb.NewTestServiceClient(te.clientConn())
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(1)),
+			Size: int32(1),
 		},
 	}
 	payload, err := newPayload(testpb.PayloadType_COMPRESSABLE, int32(1))
@@ -3906,7 +3906,7 @@ func testStreamServerInterceptor(t *testing.T, e env) {
 		t.Fatal(err)
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            payload,
 	}
@@ -4753,11 +4753,11 @@ func testConfigurableWindowSize(t *testing.T, e env, wc windowSizeConfig) {
 	}
 	respParams := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(messageSize),
+			Size: messageSize,
 		},
 	}
 	req := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParams,
 		Payload:            payload,
 	}
@@ -4994,11 +4994,11 @@ func testSvrWriteStatusEarlyWrite(t *testing.T, e env) {
 	tc := testpb.NewTestServiceClient(te.clientConn())
 	respParam := []*testpb.ResponseParameters{
 		{
-			Size: proto.Int32(int32(smallSize)),
+			Size: int32(smallSize),
 		},
 	}
 	sreq := &testpb.StreamingOutputCallRequest{
-		ResponseType:       testpb.PayloadType_COMPRESSABLE.Enum(),
+		ResponseType:       testpb.PayloadType_COMPRESSABLE,
 		ResponseParameters: respParam,
 		Payload:            extraLargePayload,
 	}
@@ -5015,7 +5015,7 @@ func testSvrWriteStatusEarlyWrite(t *testing.T, e env) {
 	}
 	// Test send case: server sends a message larger than maxServerSendMsgSize.
 	sreq.Payload = smallPayload
-	respParam[0].Size = proto.Int32(int32(extraLargeSize))
+	respParam[0].Size = int32(extraLargeSize)
 
 	stream, err = tc.FullDuplexCall(te.ctx)
 	if err != nil {
diff --git a/test/grpc_testing/test.pb.go b/test/grpc_testing/test.pb.go
index bb6efbe7..ab48a152 100644
--- a/test/grpc_testing/test.pb.go
+++ b/test/grpc_testing/test.pb.go
@@ -63,26 +63,12 @@ var PayloadType_value = map[string]int32{
 	"RANDOM":         2,
 }
 
-func (x PayloadType) Enum() *PayloadType {
-	p := new(PayloadType)
-	*p = x
-	return p
-}
 func (x PayloadType) String() string {
 	return proto.EnumName(PayloadType_name, int32(x))
 }
-func (x *PayloadType) UnmarshalJSON(data []byte) error {
-	value, err := proto.UnmarshalJSONEnum(PayloadType_value, data, "PayloadType")
-	if err != nil {
-		return err
-	}
-	*x = PayloadType(value)
-	return nil
-}
 func (PayloadType) EnumDescriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
 
 type Empty struct {
-	XXX_unrecognized []byte `json:"-"`
 }
 
 func (m *Empty) Reset()                    { *m = Empty{} }
@@ -93,10 +79,9 @@ func (*Empty) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{0} }
 // A block of data, to simply increase gRPC message size.
 type Payload struct {
 	// The type of data in body.
-	Type *PayloadType `protobuf:"varint,1,opt,name=type,enum=grpc.testing.PayloadType" json:"type,omitempty"`
+	Type PayloadType `protobuf:"varint,1,opt,name=type,enum=grpc.testing.PayloadType" json:"type,omitempty"`
 	// Primary contents of payload.
-	Body             []byte `protobuf:"bytes,2,opt,name=body" json:"body,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	Body []byte `protobuf:"bytes,2,opt,name=body,proto3" json:"body,omitempty"`
 }
 
 func (m *Payload) Reset()                    { *m = Payload{} }
@@ -105,8 +90,8 @@ func (*Payload) ProtoMessage()               {}
 func (*Payload) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{1} }
 
 func (m *Payload) GetType() PayloadType {
-	if m != nil && m.Type != nil {
-		return *m.Type
+	if m != nil {
+		return m.Type
 	}
 	return PayloadType_COMPRESSABLE
 }
@@ -122,17 +107,16 @@ func (m *Payload) GetBody() []byte {
 type SimpleRequest struct {
 	// Desired payload type in the response from the server.
 	// If response_type is RANDOM, server randomly chooses one from other formats.
-	ResponseType *PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
+	ResponseType PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
 	// Desired payload size in the response from the server.
 	// If response_type is COMPRESSABLE, this denotes the size before compression.
-	ResponseSize *int32 `protobuf:"varint,2,opt,name=response_size,json=responseSize" json:"response_size,omitempty"`
+	ResponseSize int32 `protobuf:"varint,2,opt,name=response_size,json=responseSize" json:"response_size,omitempty"`
 	// Optional input payload sent along with the request.
 	Payload *Payload `protobuf:"bytes,3,opt,name=payload" json:"payload,omitempty"`
 	// Whether SimpleResponse should include username.
-	FillUsername *bool `protobuf:"varint,4,opt,name=fill_username,json=fillUsername" json:"fill_username,omitempty"`
+	FillUsername bool `protobuf:"varint,4,opt,name=fill_username,json=fillUsername" json:"fill_username,omitempty"`
 	// Whether SimpleResponse should include OAuth scope.
-	FillOauthScope   *bool  `protobuf:"varint,5,opt,name=fill_oauth_scope,json=fillOauthScope" json:"fill_oauth_scope,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	FillOauthScope bool `protobuf:"varint,5,opt,name=fill_oauth_scope,json=fillOauthScope" json:"fill_oauth_scope,omitempty"`
 }
 
 func (m *SimpleRequest) Reset()                    { *m = SimpleRequest{} }
@@ -141,15 +125,15 @@ func (*SimpleRequest) ProtoMessage()               {}
 func (*SimpleRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{2} }
 
 func (m *SimpleRequest) GetResponseType() PayloadType {
-	if m != nil && m.ResponseType != nil {
-		return *m.ResponseType
+	if m != nil {
+		return m.ResponseType
 	}
 	return PayloadType_COMPRESSABLE
 }
 
 func (m *SimpleRequest) GetResponseSize() int32 {
-	if m != nil && m.ResponseSize != nil {
-		return *m.ResponseSize
+	if m != nil {
+		return m.ResponseSize
 	}
 	return 0
 }
@@ -162,15 +146,15 @@ func (m *SimpleRequest) GetPayload() *Payload {
 }
 
 func (m *SimpleRequest) GetFillUsername() bool {
-	if m != nil && m.FillUsername != nil {
-		return *m.FillUsername
+	if m != nil {
+		return m.FillUsername
 	}
 	return false
 }
 
 func (m *SimpleRequest) GetFillOauthScope() bool {
-	if m != nil && m.FillOauthScope != nil {
-		return *m.FillOauthScope
+	if m != nil {
+		return m.FillOauthScope
 	}
 	return false
 }
@@ -181,10 +165,9 @@ type SimpleResponse struct {
 	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 	// The user the request came from, for verifying authentication was
 	// successful when the client expected it.
-	Username *string `protobuf:"bytes,2,opt,name=username" json:"username,omitempty"`
+	Username string `protobuf:"bytes,2,opt,name=username" json:"username,omitempty"`
 	// OAuth scope.
-	OauthScope       *string `protobuf:"bytes,3,opt,name=oauth_scope,json=oauthScope" json:"oauth_scope,omitempty"`
-	XXX_unrecognized []byte  `json:"-"`
+	OauthScope string `protobuf:"bytes,3,opt,name=oauth_scope,json=oauthScope" json:"oauth_scope,omitempty"`
 }
 
 func (m *SimpleResponse) Reset()                    { *m = SimpleResponse{} }
@@ -200,15 +183,15 @@ func (m *SimpleResponse) GetPayload() *Payload {
 }
 
 func (m *SimpleResponse) GetUsername() string {
-	if m != nil && m.Username != nil {
-		return *m.Username
+	if m != nil {
+		return m.Username
 	}
 	return ""
 }
 
 func (m *SimpleResponse) GetOauthScope() string {
-	if m != nil && m.OauthScope != nil {
-		return *m.OauthScope
+	if m != nil {
+		return m.OauthScope
 	}
 	return ""
 }
@@ -216,8 +199,7 @@ func (m *SimpleResponse) GetOauthScope() string {
 // Client-streaming request.
 type StreamingInputCallRequest struct {
 	// Optional input payload sent along with the request.
-	Payload          *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
-	XXX_unrecognized []byte   `json:"-"`
+	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 }
 
 func (m *StreamingInputCallRequest) Reset()                    { *m = StreamingInputCallRequest{} }
@@ -235,8 +217,7 @@ func (m *StreamingInputCallRequest) GetPayload() *Payload {
 // Client-streaming response.
 type StreamingInputCallResponse struct {
 	// Aggregated size of payloads received from the client.
-	AggregatedPayloadSize *int32 `protobuf:"varint,1,opt,name=aggregated_payload_size,json=aggregatedPayloadSize" json:"aggregated_payload_size,omitempty"`
-	XXX_unrecognized      []byte `json:"-"`
+	AggregatedPayloadSize int32 `protobuf:"varint,1,opt,name=aggregated_payload_size,json=aggregatedPayloadSize" json:"aggregated_payload_size,omitempty"`
 }
 
 func (m *StreamingInputCallResponse) Reset()                    { *m = StreamingInputCallResponse{} }
@@ -245,8 +226,8 @@ func (*StreamingInputCallResponse) ProtoMessage()               {}
 func (*StreamingInputCallResponse) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{5} }
 
 func (m *StreamingInputCallResponse) GetAggregatedPayloadSize() int32 {
-	if m != nil && m.AggregatedPayloadSize != nil {
-		return *m.AggregatedPayloadSize
+	if m != nil {
+		return m.AggregatedPayloadSize
 	}
 	return 0
 }
@@ -255,11 +236,10 @@ func (m *StreamingInputCallResponse) GetAggregatedPayloadSize() int32 {
 type ResponseParameters struct {
 	// Desired payload sizes in responses from the server.
 	// If response_type is COMPRESSABLE, this denotes the size before compression.
-	Size *int32 `protobuf:"varint,1,opt,name=size" json:"size,omitempty"`
+	Size int32 `protobuf:"varint,1,opt,name=size" json:"size,omitempty"`
 	// Desired interval between consecutive responses in the response stream in
 	// microseconds.
-	IntervalUs       *int32 `protobuf:"varint,2,opt,name=interval_us,json=intervalUs" json:"interval_us,omitempty"`
-	XXX_unrecognized []byte `json:"-"`
+	IntervalUs int32 `protobuf:"varint,2,opt,name=interval_us,json=intervalUs" json:"interval_us,omitempty"`
 }
 
 func (m *ResponseParameters) Reset()                    { *m = ResponseParameters{} }
@@ -268,15 +248,15 @@ func (*ResponseParameters) ProtoMessage()               {}
 func (*ResponseParameters) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{6} }
 
 func (m *ResponseParameters) GetSize() int32 {
-	if m != nil && m.Size != nil {
-		return *m.Size
+	if m != nil {
+		return m.Size
 	}
 	return 0
 }
 
 func (m *ResponseParameters) GetIntervalUs() int32 {
-	if m != nil && m.IntervalUs != nil {
-		return *m.IntervalUs
+	if m != nil {
+		return m.IntervalUs
 	}
 	return 0
 }
@@ -287,12 +267,11 @@ type StreamingOutputCallRequest struct {
 	// If response_type is RANDOM, the payload from each response in the stream
 	// might be of different types. This is to simulate a mixed type of payload
 	// stream.
-	ResponseType *PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
+	ResponseType PayloadType `protobuf:"varint,1,opt,name=response_type,json=responseType,enum=grpc.testing.PayloadType" json:"response_type,omitempty"`
 	// Configuration for each expected response message.
 	ResponseParameters []*ResponseParameters `protobuf:"bytes,2,rep,name=response_parameters,json=responseParameters" json:"response_parameters,omitempty"`
 	// Optional input payload sent along with the request.
-	Payload          *Payload `protobuf:"bytes,3,opt,name=payload" json:"payload,omitempty"`
-	XXX_unrecognized []byte   `json:"-"`
+	Payload *Payload `protobuf:"bytes,3,opt,name=payload" json:"payload,omitempty"`
 }
 
 func (m *StreamingOutputCallRequest) Reset()                    { *m = StreamingOutputCallRequest{} }
@@ -301,8 +280,8 @@ func (*StreamingOutputCallRequest) ProtoMessage()               {}
 func (*StreamingOutputCallRequest) Descriptor() ([]byte, []int) { return fileDescriptor0, []int{7} }
 
 func (m *StreamingOutputCallRequest) GetResponseType() PayloadType {
-	if m != nil && m.ResponseType != nil {
-		return *m.ResponseType
+	if m != nil {
+		return m.ResponseType
 	}
 	return PayloadType_COMPRESSABLE
 }
@@ -324,8 +303,7 @@ func (m *StreamingOutputCallRequest) GetPayload() *Payload {
 // Server-streaming response, as configured by the request and parameters.
 type StreamingOutputCallResponse struct {
 	// Payload to increase response size.
-	Payload          *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
-	XXX_unrecognized []byte   `json:"-"`
+	Payload *Payload `protobuf:"bytes,1,opt,name=payload" json:"payload,omitempty"`
 }
 
 func (m *StreamingOutputCallResponse) Reset()                    { *m = StreamingOutputCallResponse{} }
@@ -747,42 +725,42 @@ var _TestService_serviceDesc = grpc.ServiceDesc{
 func init() { proto.RegisterFile("grpc_testing/test.proto", fileDescriptor0) }
 
 var fileDescriptor0 = []byte{
-	// 582 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xbc, 0x54, 0xdd, 0x6e, 0xd3, 0x4c,
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-	0xa3, 0x25, 0xd9, 0x1a, 0x4b, 0x8e, 0xbd, 0xac, 0xd7, 0x15, 0xe9, 0x05, 0x2f, 0xc6, 0xcb, 0xf0,
-	0x10, 0x3c, 0x00, 0x5a, 0xff, 0x24, 0x4e, 0xe2, 0x8a, 0x14, 0x04, 0x57, 0xb6, 0x67, 0xce, 0x9c,
-	0x39, 0xc7, 0x33, 0xbb, 0x70, 0xe4, 0x70, 0x36, 0x9d, 0x08, 0x1a, 0x0a, 0xd7, 0x77, 0x4e, 0xe5,
-	0xb3, 0xcd, 0x78, 0x20, 0x02, 0xdc, 0x90, 0x89, 0x76, 0x9a, 0x30, 0xaa, 0x50, 0xe9, 0xce, 0x99,
-	0x58, 0x18, 0x3d, 0xa8, 0x0e, 0xc9, 0xc2, 0x0b, 0xc8, 0x0c, 0xbf, 0x80, 0xb2, 0x58, 0x30, 0xaa,
-	0x22, 0x1d, 0x99, 0x4a, 0xe7, 0xb8, 0x9d, 0x2f, 0x68, 0xa7, 0xa0, 0xd1, 0x82, 0x51, 0x2b, 0x86,
-	0x61, 0x0c, 0xe5, 0x8f, 0xc1, 0x6c, 0xa1, 0xee, 0xe9, 0xc8, 0x6c, 0x58, 0xf1, 0xbb, 0xf1, 0x03,
-	0xc1, 0x81, 0xed, 0xce, 0x99, 0x47, 0x2d, 0xfa, 0x39, 0xa2, 0xa1, 0xc0, 0x6f, 0xe0, 0x80, 0xd3,
-	0x90, 0x05, 0x7e, 0x48, 0x27, 0xbb, 0xb1, 0x37, 0x32, 0xbc, 0xfc, 0xc2, 0x4f, 0x72, 0xf5, 0xa1,
-	0x7b, 0x47, 0xe3, 0x76, 0x95, 0x15, 0xc8, 0x76, 0xef, 0x28, 0x3e, 0x85, 0x2a, 0x4b, 0x18, 0xd4,
-	0x92, 0x8e, 0xcc, 0x7a, 0xe7, 0xb0, 0x90, 0xde, 0xca, 0x50, 0x92, 0xf5, 0xc6, 0xf5, 0xbc, 0x49,
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-	0x36, 0xa1, 0x19, 0x83, 0x02, 0x12, 0x89, 0x4f, 0x93, 0x70, 0x1a, 0x30, 0xaa, 0x56, 0x62, 0x9c,
-	0x22, 0xe3, 0x03, 0x19, 0xb6, 0x65, 0xd4, 0xf8, 0x0a, 0x4a, 0xe6, 0x3a, 0x51, 0x95, 0x57, 0x84,
-	0x76, 0x52, 0xa4, 0xc1, 0xfe, 0x52, 0x8c, 0xb4, 0x58, 0xb3, 0x96, 0xdf, 0xf8, 0x31, 0xd4, 0xf3,
-	0x1a, 0x4a, 0x71, 0x1a, 0x82, 0x55, 0xff, 0x1e, 0x1c, 0xdb, 0x82, 0x53, 0x32, 0x77, 0x7d, 0xe7,
-	0xca, 0x67, 0x91, 0x38, 0x27, 0x9e, 0x97, 0x4d, 0xe0, 0xa1, 0x52, 0x8c, 0x11, 0x68, 0x45, 0x6c,
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-	0xd6, 0x3b, 0xfa, 0x3a, 0xcb, 0xb6, 0x25, 0x0b, 0xf3, 0x6d, 0x9b, 0x0f, 0x5d, 0x50, 0xa3, 0x0f,
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-	0xe1, 0xd6, 0x7a, 0xf7, 0x38, 0xa1, 0x15, 0x05, 0xf1, 0x25, 0xd4, 0xc6, 0x3e, 0xe1, 0x49, 0xd9,
-	0xc9, 0x3a, 0x62, 0xed, 0xe2, 0xd0, 0x1e, 0x15, 0x27, 0xd3, 0x1f, 0xe0, 0x41, 0xab, 0xe0, 0xff,
-	0x60, 0x73, 0xa3, 0xe8, 0xde, 0x25, 0xd1, 0x9e, 0xed, 0x80, 0x4c, 0x7a, 0xbd, 0x44, 0xd8, 0x05,
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-	0x65, 0x2b, 0xe5, 0x32, 0xf2, 0xbc, 0x8b, 0x88, 0x79, 0xf4, 0xcb, 0x5f, 0xf3, 0x64, 0xa2, 0xd8,
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-	0x30, 0x01, 0x96, 0x06, 0x00, 0x00,
+	// 587 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xbc, 0x55, 0xdb, 0x6e, 0xd3, 0x40,
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+	0x0c, 0xff, 0xed, 0xca, 0x7d, 0x82, 0xbd, 0x69, 0x3d, 0x9b, 0x4a, 0xd5, 0xd7, 0xcc, 0x75, 0xbb,
+	0xda, 0x34, 0xe7, 0x59, 0x96, 0x2d, 0x39, 0x98, 0x2f, 0xdb, 0x7c, 0xe8, 0x82, 0x5a, 0x6d, 0x38,
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+	0xab, 0xae, 0x73, 0xee, 0xba, 0x27, 0x1f, 0x5a, 0xe7, 0xf5, 0x47, 0x18, 0x83, 0xd6, 0x6f, 0xcf,
+	0xc5, 0x10, 0x06, 0xd8, 0x74, 0x4e, 0xda, 0x67, 0x9d, 0xab, 0xfa, 0x5a, 0xf3, 0x7b, 0x05, 0xaa,
+	0x3d, 0x1a, 0x0b, 0x97, 0xf2, 0x5b, 0x7f, 0x48, 0xf1, 0x1b, 0xd8, 0x51, 0x17, 0x88, 0x94, 0x85,
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+	0xe6, 0x11, 0x73, 0x17, 0x87, 0xf1, 0xb8, 0x3c, 0x99, 0x7d, 0x80, 0x00, 0xf6, 0x4a, 0xbe, 0x0f,
+	0xb6, 0x17, 0x8a, 0xee, 0x5d, 0x12, 0xe3, 0xf9, 0x0a, 0xc8, 0xb4, 0xd7, 0x2b, 0x84, 0x7d, 0xc0,
+	0xcb, 0x27, 0x02, 0x3f, 0xbb, 0x87, 0x62, 0xf1, 0x04, 0x1a, 0xf6, 0xef, 0x81, 0x69, 0x2b, 0x5b,
+	0xb6, 0xd2, 0x2e, 0x92, 0x20, 0x38, 0x4b, 0x58, 0x40, 0xbf, 0xfe, 0x33, 0x4f, 0x36, 0x52, 0xae,
+	0xb4, 0x8f, 0x24, 0xb8, 0xf9, 0x0f, 0xad, 0xae, 0x37, 0xd5, 0x7f, 0xd0, 0xeb, 0x5f, 0x01, 0x00,
+	0x00, 0xff, 0xff, 0x07, 0xc7, 0x76, 0x69, 0x9e, 0x06, 0x00, 0x00,
 }
diff --git a/test/grpc_testing/test.proto b/test/grpc_testing/test.proto
index fbd22dec..6f62f3a7 100644
--- a/test/grpc_testing/test.proto
+++ b/test/grpc_testing/test.proto
@@ -14,7 +14,7 @@
 
 // An integration test service that covers all the method signature permutations
 // of unary/streaming requests/responses.
-syntax = "proto2";
+syntax = "proto3";
 
 package grpc.testing;
 
@@ -35,48 +35,48 @@ enum PayloadType {
 // A block of data, to simply increase gRPC message size.
 message Payload {
   // The type of data in body.
-  optional PayloadType type = 1;
+  PayloadType type = 1;
   // Primary contents of payload.
-  optional bytes body = 2;
+  bytes body = 2;
 }
 
 // Unary request.
 message SimpleRequest {
   // Desired payload type in the response from the server.
   // If response_type is RANDOM, server randomly chooses one from other formats.
-  optional PayloadType response_type = 1;
+  PayloadType response_type = 1;
 
   // Desired payload size in the response from the server.
   // If response_type is COMPRESSABLE, this denotes the size before compression.
-  optional int32 response_size = 2;
+  int32 response_size = 2;
 
   // Optional input payload sent along with the request.
-  optional Payload payload = 3;
+  Payload payload = 3;
 
   // Whether SimpleResponse should include username.
-  optional bool fill_username = 4;
+  bool fill_username = 4;
 
   // Whether SimpleResponse should include OAuth scope.
-  optional bool fill_oauth_scope = 5;
+  bool fill_oauth_scope = 5;
 }
 
 // Unary response, as configured by the request.
 message SimpleResponse {
   // Payload to increase message size.
-  optional Payload payload = 1;
+  Payload payload = 1;
 
   // The user the request came from, for verifying authentication was
   // successful when the client expected it.
-  optional string username = 2;
+  string username = 2;
   
   // OAuth scope.
-  optional string oauth_scope = 3;
+  string oauth_scope = 3;
 }
 
 // Client-streaming request.
 message StreamingInputCallRequest {
   // Optional input payload sent along with the request.
-  optional Payload payload = 1;
+  Payload payload = 1;
 
   // Not expecting any payload from the response.
 }
@@ -84,18 +84,18 @@ message StreamingInputCallRequest {
 // Client-streaming response.
 message StreamingInputCallResponse {
   // Aggregated size of payloads received from the client.
-  optional int32 aggregated_payload_size = 1;
+  int32 aggregated_payload_size = 1;
 }
 
 // Configuration for a particular response.
 message ResponseParameters {
   // Desired payload sizes in responses from the server.
   // If response_type is COMPRESSABLE, this denotes the size before compression.
-  optional int32 size = 1;
+  int32 size = 1;
 
   // Desired interval between consecutive responses in the response stream in
   // microseconds.
-  optional int32 interval_us = 2;
+  int32 interval_us = 2;
 }
 
 // Server-streaming request.
@@ -104,19 +104,19 @@ message StreamingOutputCallRequest {
   // If response_type is RANDOM, the payload from each response in the stream
   // might be of different types. This is to simulate a mixed type of payload
   // stream.
-  optional PayloadType response_type = 1;
+  PayloadType response_type = 1;
 
   // Configuration for each expected response message.
   repeated ResponseParameters response_parameters = 2;
 
   // Optional input payload sent along with the request.
-  optional Payload payload = 3;
+  Payload payload = 3;
 }
 
 // Server-streaming response, as configured by the request and parameters.
 message StreamingOutputCallResponse {
   // Payload to increase response size.
-  optional Payload payload = 1;
+  Payload payload = 1;
 }
 
 // A simple service to test the various types of RPCs and experiment with