Modify converter to allow setting values for object and array (#687)

PR#678 triggers the regression error, so I made corrections and
re-submitted. I've added handling for cases where values are not set
when converting to PbJSONElementSimple. In the bytesToObject function,
It was previously creating a new object with initialTicket when the
bytes were nil. However, this logic became inappropriate after
separating it from bytesToSnapshot, so I removed it.

api/converter/converter_test.go

@@ -36,13 +36,8 @@ import (
 
 func TestConverter(t *testing.T) {
 	t.Run("snapshot simple test", func(t *testing.T) {
-		obj, err := converter.BytesToObject(nil)
-		assert.NoError(t, err)
-		assert.Equal(t, "{}", obj.Marshal())
-
 		doc := document.New("d1")
-
-		err = doc.Update(func(root *json.Object, p *presence.Presence) error {
+		err := doc.Update(func(root *json.Object, p *presence.Presence) error {
 			root.SetNewText("k1").Edit(0, 0, "A")
 			return nil
 		})
@@ -59,7 +54,7 @@ func TestConverter(t *testing.T) {
 		bytes, err := converter.ObjectToBytes(doc.RootObject())
 		assert.NoError(t, err)
 
-		obj, err = converter.BytesToObject(bytes)
+		obj, err := converter.BytesToObject(bytes)
 		assert.NoError(t, err)
 		assert.Equal(t, `{"k1":[{"val":"B"}]}`, obj.Marshal())
 	})
@@ -243,6 +238,28 @@ func TestConverter(t *testing.T) {
 		assert.Equal(t, tree.ToXML(), clone.ToXML())
 	})
 
+	t.Run("array converting to bytes test", func(t *testing.T) {
+		root := helper.TestRoot()
+		ctx := helper.TextChangeContext(root)
+
+		treeList := crdt.NewRGATreeList()
+		arr := crdt.NewArray(treeList, ctx.IssueTimeTicket())
+		primitive, _ := crdt.NewPrimitive("1", ctx.IssueTimeTicket())
+		_ = arr.Add(primitive)
+		primitive, _ = crdt.NewPrimitive("2", ctx.IssueTimeTicket())
+		_ = arr.Add(primitive)
+		primitive, _ = crdt.NewPrimitive("3", ctx.IssueTimeTicket())
+		_ = arr.Add(primitive)
+
+		bytes, err := converter.ArrayToBytes(arr)
+		assert.NoError(t, err)
+		clone, err := converter.BytesToArray(bytes)
+		assert.NoError(t, err)
+
+		assert.Equal(t, `["1","2","3"]`, arr.Marshal())
+		assert.Equal(t, `["1","2","3"]`, clone.Marshal())
+	})
+
 	t.Run("empty presence converting test", func(t *testing.T) {
 		change, err := innerpresence.NewChangeFromJSON(`{"ChangeType":"put","Presence":{}}`)
 		assert.NoError(t, err)

api/converter/from_bytes.go

@@ -51,7 +51,7 @@ func BytesToSnapshot(snapshot []byte) (*crdt.Object, *innerpresence.Map, error)
 // BytesToObject creates an Object from the given byte array.
 func BytesToObject(snapshot []byte) (*crdt.Object, error) {
 	if snapshot == nil {
-		return crdt.NewObject(crdt.NewElementRHT(), time.InitialTicket), nil
+		return nil, errors.New("snapshot should not be nil")
 	}
 
 	pbElem := &api.JSONElement{}
@@ -67,6 +67,25 @@ func BytesToObject(snapshot []byte) (*crdt.Object, error) {
 	return obj, nil
 }
 
+// BytesToArray creates a Array from the given byte array.
+func BytesToArray(snapshot []byte) (*crdt.Array, error) {
+	if snapshot == nil {
+		return nil, errors.New("snapshot should not be nil")
+	}
+
+	pbArray := &api.JSONElement{}
+	if err := proto.Unmarshal(snapshot, pbArray); err != nil {
+		return nil, fmt.Errorf("unmarshal array: %w", err)
+	}
+
+	array, err := fromJSONArray(pbArray.GetJsonArray())
+	if err != nil {
+		return nil, err
+	}
+
+	return array, nil
+}
+
 // BytesToTree creates a Tree from the given byte array.
 func BytesToTree(snapshot []byte) (*crdt.Tree, error) {
 	if snapshot == nil {

api/converter/from_pb.go

@@ -728,21 +728,27 @@ func fromTimeTicket(pbTicket *api.TimeTicket) (*time.Ticket, error) {
 func fromElement(pbElement *api.JSONElementSimple) (crdt.Element, error) {
 	switch pbType := pbElement.Type; pbType {
 	case api.ValueType_VALUE_TYPE_JSON_OBJECT:
-		createdAt, err := fromTimeTicket(pbElement.CreatedAt)
-		if err != nil {
-			return nil, err
+		if pbElement.Value == nil {
+			createdAt, err := fromTimeTicket(pbElement.CreatedAt)
+			if err != nil {
+				return nil, err
+			}
+			return crdt.NewObject(
+				crdt.NewElementRHT(),
+				createdAt,
+			), nil
 		}
-		return crdt.NewObject(
-			crdt.NewElementRHT(),
-			createdAt,
-		), nil
+		return BytesToObject(pbElement.Value)
 	case api.ValueType_VALUE_TYPE_JSON_ARRAY:
-		createdAt, err := fromTimeTicket(pbElement.CreatedAt)
-		if err != nil {
-			return nil, err
+		if pbElement.Value == nil {
+			createdAt, err := fromTimeTicket(pbElement.CreatedAt)
+			if err != nil {
+				return nil, err
+			}
+			elements := crdt.NewRGATreeList()
+			return crdt.NewArray(elements, createdAt), nil
 		}
-		elements := crdt.NewRGATreeList()
-		return crdt.NewArray(elements, createdAt), nil
+		return BytesToArray(pbElement.Value)
 	case api.ValueType_VALUE_TYPE_NULL:
 		fallthrough
 	case api.ValueType_VALUE_TYPE_BOOLEAN:

api/converter/to_bytes.go

@@ -62,6 +62,19 @@ func ObjectToBytes(obj *crdt.Object) ([]byte, error) {
 	return bytes, nil
 }
 
+// ArrayToBytes converts the given array to byte array.
+func ArrayToBytes(array *crdt.Array) ([]byte, error) {
+	pbArray, err := toJSONArray(array)
+	if err != nil {
+		return nil, err
+	}
+	bytes, err := proto.Marshal(pbArray)
+	if err != nil {
+		return nil, fmt.Errorf("marshal Array to bytes: %w", err)
+	}
+	return bytes, nil
+}
+
 // TreeToBytes converts the given tree to byte array.
 func TreeToBytes(tree *crdt.Tree) ([]byte, error) {
 	pbTree := toTree(tree)

api/converter/to_pb.go

@@ -409,14 +409,24 @@ func toTreeStyle(style *operations.TreeStyle) (*api.Operation_TreeStyle_, error)
 func toJSONElementSimple(elem crdt.Element) (*api.JSONElementSimple, error) {
 	switch elem := elem.(type) {
 	case *crdt.Object:
+		bytes, err := ObjectToBytes(elem)
+		if err != nil {
+			return nil, err
+		}
 		return &api.JSONElementSimple{
 			Type:      api.ValueType_VALUE_TYPE_JSON_OBJECT,
 			CreatedAt: ToTimeTicket(elem.CreatedAt()),
+			Value:     bytes,
 		}, nil
 	case *crdt.Array:
+		bytes, err := ArrayToBytes(elem)
+		if err != nil {
+			return nil, err
+		}
 		return &api.JSONElementSimple{
 			Type:      api.ValueType_VALUE_TYPE_JSON_ARRAY,
 			CreatedAt: ToTimeTicket(elem.CreatedAt()),
+			Value:     bytes,
 		}, nil
 	case *crdt.Primitive:
 		pbValueType, err := toValueType(elem.ValueType())