Merge pull request #3297 from nspcc-dev/sc-convertible

smartcontract: introduce Convertible interface

pkg/rpcclient/nns/record.go

@@ -3,7 +3,9 @@ package nns
 import (
 	"errors"
 	"fmt"
+	"math/big"
 
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
 )
 
@@ -17,6 +19,10 @@ type RecordState struct {
 // RecordType is domain name service record types.
 type RecordType byte
 
+// Ensure RecordType implements smartcontract.Convertible for proper handling as
+// a parameter to invoker.Invoker methods.
+var _ = smartcontract.Convertible(RecordType(0))
+
 // Record types are defined in [RFC 1035](https://tools.ietf.org/html/rfc1035)
 const (
 	// A represents address record type.
@@ -33,6 +39,14 @@ const (
 	AAAA RecordType = 28
 )
 
+// ToSCParameter implements smartcontract.Convertible interface.
+func (r RecordType) ToSCParameter() (smartcontract.Parameter, error) {
+	return smartcontract.Parameter{
+		Type:  smartcontract.IntegerType,
+		Value: big.NewInt(int64(r)),
+	}, nil
+}
+
 // FromStackItem fills RecordState with data from the given stack item if it can
 // be correctly converted to RecordState.
 func (r *RecordState) FromStackItem(itm stackitem.Item) error {

pkg/smartcontract/parameter.go

@@ -25,6 +25,11 @@ type Parameter struct {
 	Value any `json:"value"`
 }
 
+// Convertible is something that can be converted to Parameter.
+type Convertible interface {
+	ToSCParameter() (Parameter, error)
+}
+
 // ParameterPair represents a key-value pair, a slice of which is stored in
 // MapType Parameter.
 type ParameterPair struct {
@@ -307,6 +312,12 @@ func NewParameterFromValue(value any) (Parameter, error) {
 		result = *v
 	case Parameter:
 		result = v
+	case Convertible:
+		var err error
+		result, err = v.ToSCParameter()
+		if err != nil {
+			return result, fmt.Errorf("failed to convert smartcontract.Convertible (%T) to Parameter: %w", v, err)
+		}
 	case util.Uint160:
 		result.Type = Hash160Type
 	case util.Uint256:

pkg/smartcontract/parameter_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"math"
 	"math/big"
 	"strings"
@@ -554,6 +555,25 @@ func TestExpandParameterToEmitableToStackitem(t *testing.T) {
 	}
 }
 
+// testConvertible implements Convertible interface and needed for NewParameterFromValue
+// test.
+type testConvertible struct {
+	i   int
+	err string
+}
+
+var _ = Convertible(testConvertible{})
+
+func (c testConvertible) ToSCParameter() (Parameter, error) {
+	if c.err != "" {
+		return Parameter{}, errors.New(c.err)
+	}
+	return Parameter{
+		Type:  IntegerType,
+		Value: c.i,
+	}, nil
+}
+
 func TestParameterFromValue(t *testing.T) {
 	pk1, _ := keys.NewPrivateKey()
 	pk2, _ := keys.NewPrivateKey()
@@ -561,6 +581,7 @@ func TestParameterFromValue(t *testing.T) {
 		value   any
 		expType ParamType
 		expVal  any
+		err     string // expected error substring
 	}{
 		{
 			value:   []byte{1, 2, 3},
@@ -741,20 +762,52 @@ func TestParameterFromValue(t *testing.T) {
 				Value: []byte{1, 2, 3},
 			}},
 		},
+		{
+			value:   testConvertible{i: 123},
+			expType: IntegerType,
+			expVal:  123,
+		},
+		{
+			value:   []any{1, testConvertible{i: 123}},
+			expType: ArrayType,
+			expVal: []Parameter{
+				{
+					Type:  IntegerType,
+					Value: big.NewInt(1),
+				},
+				{
+					Type:  IntegerType,
+					Value: 123,
+				},
+			},
+		},
+		{
+			value: testConvertible{err: "invalid i value"},
+			err:   "invalid i value",
+		},
+		{
+			value: make(map[string]int),
+			err:   "unsupported parameter map[string]int",
+		},
+		{
+			value: []any{1, 2, make(map[string]int)},
+			err:   "unsupported parameter map[string]int",
+		},
 	}
 
 	for _, item := range items {
 		t.Run(item.expType.String()+" to stack parameter", func(t *testing.T) {
 			res, err := NewParameterFromValue(item.value)
+			if item.err != "" {
+				require.Error(t, err)
+				require.Contains(t, err.Error(), item.err)
+			} else {
 				require.NoError(t, err)
 				require.Equal(t, item.expType, res.Type)
 				require.Equal(t, item.expVal, res.Value)
+			}
 		})
 	}
-	_, err := NewParameterFromValue(make(map[string]int))
-	require.Error(t, err)
-	_, err = NewParameterFromValue([]any{1, 2, make(map[string]int)})
-	require.Error(t, err)
 }
 
 func TestParametersFromValues(t *testing.T) {