[#168] sdk/accounting: Refactor Decimal type

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>

pkg/accounting/decimal.go

@@ -4,6 +4,39 @@ import (
 	"github.com/nspcc-dev/neofs-api-go/v2/accounting"
 )
 
-type Decimal struct {
-	accounting.Decimal
+// Decimal represents v2-compatible decimal number.
+type Decimal accounting.Decimal
+
+// NewDecimal creates, initializes and returns blank Decimal instance.
+func NewDecimal() *Decimal {
+	return NewDecimalFromV2(new(accounting.Decimal))
+}
+
+// NewDecimalFromV2 converts v2 Decimal to Decimal.
+func NewDecimalFromV2(d *accounting.Decimal) *Decimal {
+	return (*Decimal)(d)
+}
+
+// Value returns value of the decimal number.
+func (d *Decimal) Value() int64 {
+	return (*accounting.Decimal)(d).
+		GetValue()
+}
+
+// SetValue sets value of the decimal number.
+func (d *Decimal) SetValue(v int64) {
+	(*accounting.Decimal)(d).
+		SetValue(v)
+}
+
+// Precision returns precision of the decimal number.
+func (d *Decimal) Precision() uint32 {
+	return (*accounting.Decimal)(d).
+		GetPrecision()
+}
+
+// SetPrecision sets precision of the decimal number.
+func (d *Decimal) SetPrecision(p uint32) {
+	(*accounting.Decimal)(d).
+		SetPrecision(p)
 }

pkg/accounting/decimal_test.go

@@ -0,0 +1,25 @@
+package accounting
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestDecimal_Value(t *testing.T) {
+	d := NewDecimal()
+
+	v := int64(3)
+	d.SetValue(v)
+
+	require.Equal(t, v, d.Value())
+}
+
+func TestDecimal_Precision(t *testing.T) {
+	d := NewDecimal()
+
+	p := uint32(3)
+	d.SetPrecision(p)
+
+	require.Equal(t, p, d.Precision())
+}

pkg/client/accounting.go

@@ -69,9 +69,7 @@ func (c Client) getBalanceV2(ctx context.Context, owner *owner.ID, opts ...CallO
 			return nil, errors.Wrap(err, "can't verify response message")
 		}
 
-		return &accounting.Decimal{
-			Decimal: *resp.GetBody().GetBalance(),
-		}, nil
+		return accounting.NewDecimalFromV2(resp.GetBody().GetBalance()), nil
 	default:
 		return nil, unsupportedProtocolErr
 	}

pkg/client/client_test.go

@@ -27,7 +27,7 @@ func TestExample(t *testing.T) {
 	resp, err := cli.GetSelfBalance(context.Background())
 	require.NoError(t, err)
 
-	fmt.Println(resp.GetValue(), resp.GetPrecision())
+	fmt.Println(resp.Value(), resp.Precision())
 
 	// create client from grpc connection
 	conn, err := grpc.DialContext(context.Background(), target, grpc.WithBlock(), grpc.WithInsecure())