feat: add Clone() function (#83)

add new `csproto.Clone()` function and associated tests
add `go.work*` to `.gitignore`

.gitignore

@@ -6,3 +6,6 @@ dist/
 
 # editor-related files
 .vscode/
+
+# Go workspace files
+go.work*

clone.go

@@ -0,0 +1,25 @@
+package csproto
+
+import (
+	gogo "github.com/gogo/protobuf/proto"
+	google "github.com/golang/protobuf/proto" //nolint: staticcheck // we're using this deprecated package intentionally
+	googlev2 "google.golang.org/protobuf/proto"
+)
+
+// Clone returns a deep copy of m, delegating to the appropriate underlying Protobuf API based on
+// the concrete type of m.  Since the underlying runtimes return different types, this function returns
+// interface{} and the caller will need to type-assert back to the concrete type of m.
+//
+// If m is not one of the supported message types, this function returns nil.
+func Clone(m interface{}) interface{} {
+	switch MsgType(m) {
+	case MessageTypeGoogle:
+		return googlev2.Clone(m.(googlev2.Message))
+	case MessageTypeGoogleV1:
+		return google.Clone(m.(google.Message))
+	case MessageTypeGogo:
+		return gogo.Clone(m.(gogo.Message))
+	default:
+		return nil
+	}
+}

example/proto2_gogo_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/gogo/protobuf/types"
@@ -251,6 +252,15 @@ func TestProto2GogoEqual(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto2GogoClone(t *testing.T) {
+	m1 := createTestProto2GogoMessage()
+	m2, ok := csproto.Clone(m1).(*gogo.BaseEvent)
+
+	assert.True(t, ok, "type assertion to *gogo.BaseEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto2GogoMessage() *gogo.BaseEvent {
 	now := uint64(time.Now().UTC().Unix())
 	et := gogo.EventType_EVENT_TYPE_ONE

example/proto2_googlev1_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/golang/protobuf/proto"
 	"github.com/stretchr/testify/assert"
@@ -278,6 +279,15 @@ func TestProto2GoogleV1Equal(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto2GoogleV1Clone(t *testing.T) {
+	m1 := createTestProto2GoogleV1Message()
+	m2, ok := csproto.Clone(m1).(*googlev1.BaseEvent)
+
+	assert.True(t, ok, "type assertion to *gogo.BaseEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto2GoogleV1Message() *googlev1.BaseEvent {
 	now := uint64(time.Now().UTC().Unix())
 	et := googlev1.EventType_EVENT_TYPE_ONE

example/proto2_googlev2_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/protobuf/proto"
@@ -278,6 +279,15 @@ func TestProto2GoogleV2Equal(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto2GoogleV2Clone(t *testing.T) {
+	m1 := createTestProto2GoogleV2Message()
+	m2, ok := csproto.Clone(m1).(*googlev2.BaseEvent)
+
+	assert.True(t, ok, "type assertion to *googlev2.BaseEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto2GoogleV2Message() *googlev2.BaseEvent {
 	now := uint64(time.Now().UTC().Unix())
 	et := googlev2.EventType_EVENT_TYPE_ONE

example/proto3_gogo_test.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/gogo/protobuf/proto"
 	"github.com/gogo/protobuf/types"
@@ -248,6 +249,15 @@ func TestProto3GogoEqual(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto3GogoClone(t *testing.T) {
+	m1 := createTestProto3GogoMessage()
+	m2, ok := csproto.Clone(m1).(*gogo.TestEvent)
+
+	assert.True(t, ok, "type assertion to *gogo.TestEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto3GogoMessage() *gogo.TestEvent {
 	event := gogo.TestEvent{
 		Name:   "test",

example/proto3_googlev1_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/golang/protobuf/proto"
 	"github.com/stretchr/testify/assert"
@@ -256,6 +257,15 @@ func TestProto3GoogleV1Equal(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto3GoogleV1Clone(t *testing.T) {
+	m1 := createTestProto3GoogleV1Message()
+	m2, ok := csproto.Clone(m1).(*googlev1.TestEvent)
+
+	assert.True(t, ok, "type assertion to *googlev1.TestEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto3GoogleV1Message() *googlev1.TestEvent {
 	event := googlev1.TestEvent{
 		Name:   "test",

example/proto3_googlev2_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 	"time"
+	"unsafe"
 
 	"github.com/stretchr/testify/assert"
 	"google.golang.org/protobuf/proto"
@@ -256,6 +257,15 @@ func TestProto3GoogleV2Equal(t *testing.T) {
 	assert.True(t, csproto.Equal(m1, m2), "messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
 }
 
+func TestProto3GoogleV2Clone(t *testing.T) {
+	m1 := createTestProto3GoogleV2Message()
+	m2, ok := csproto.Clone(m1).(*googlev2.TestEvent)
+
+	assert.True(t, ok, "type assertion to *googlev2.TestEvent should succeed")
+	assert.True(t, csproto.Equal(m1, m2), "cloned messages should be equal\nm1=%s\nm2=%s", m1.String(), m2.String())
+	assert.NotEqual(t, unsafe.Pointer(m1), unsafe.Pointer(m2))
+}
+
 func createTestProto3GoogleV2Message() *googlev2.TestEvent {
 	event := googlev2.TestEvent{
 		Name:   "test",