core: implement Neo.InvocationTransaction.GetScript

pkg/core/interop_neo.go

@@ -198,6 +198,24 @@ func (ic *interopContext) txGetWitnesses(v *vm.VM) error {
 	return nil
 }
 
+// invocationTx_GetScript returns invocation script from the current transaction.
+func (ic *interopContext) invocationTxGetScript(v *vm.VM) error {
+	txInterface := v.Estack().Pop().Value()
+	tx, ok := txInterface.(*transaction.Transaction)
+	if !ok {
+		return errors.New("value is not a transaction")
+	}
+	inv, ok := tx.Data.(*transaction.InvocationTX)
+	if tx.Type != transaction.InvocationType || !ok {
+		return errors.New("value is not an invocation transaction")
+	}
+	// It's important not to share inv.Script slice with the code running in VM.
+	script := make([]byte, len(inv.Script))
+	copy(script, inv.Script)
+	v.Estack().PushVal(script)
+	return nil
+}
+
 // bcGetValidators returns validators.
 func (ic *interopContext) bcGetValidators(v *vm.VM) error {
 	validators := ic.dao.GetValidators()

pkg/core/interop_neo_test.go

@@ -13,6 +13,7 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/smartcontract/trigger"
 	"github.com/CityOfZion/neo-go/pkg/util"
 	"github.com/CityOfZion/neo-go/pkg/vm"
+	"github.com/CityOfZion/neo-go/pkg/vm/opcode"
 	"github.com/stretchr/testify/require"
 )
 
@@ -115,6 +116,16 @@ func TestTxGetType(t *testing.T) {
 	require.Equal(t, big.NewInt(int64(tx.Type)), value)
 }
 
+func TestInvocationTxGetScript(t *testing.T) {
+	v, tx, context := createVMAndPushTX(t)
+
+	err := context.invocationTxGetScript(v)
+	require.NoError(t, err)
+	value := v.Estack().Pop().Value().([]byte)
+	inv := tx.Data.(*transaction.InvocationTX)
+	require.Equal(t, inv.Script, value)
+}
+
 func TestPopInputFromVM(t *testing.T) {
 	v, tx, _ := createVMAndTX(t)
 	v.Estack().PushVal(vm.NewInteropItem(&tx.Inputs[0]))
@@ -395,7 +406,8 @@ func createVMAndAccState(t *testing.T) (*vm.VM, *state.Account, *interopContext)
 
 func createVMAndTX(t *testing.T) (*vm.VM, *transaction.Transaction, *interopContext) {
 	v := vm.New()
-	tx := newMinerTX()
+	script := []byte{byte(opcode.PUSH1), byte(opcode.RET)}
+	tx := transaction.NewInvocationTX(script, 0)
 
 	bytes := make([]byte, 1)
 	attributes := append(tx.Attributes, transaction.Attribute{

pkg/core/interops.go

@@ -152,6 +152,7 @@ var neoInterops = []interopedFunction{
 	{Name: "Neo.Header.GetVersion", Func: (*interopContext).headerGetVersion, Price: 1},
 	{Name: "Neo.Input.GetHash", Func: (*interopContext).inputGetHash, Price: 1},
 	{Name: "Neo.Input.GetIndex", Func: (*interopContext).inputGetIndex, Price: 1},
+	{Name: "Neo.InvocationTransaction.GetScript", Func: (*interopContext).invocationTxGetScript, Price: 1},
 	{Name: "Neo.Output.GetAssetId", Func: (*interopContext).outputGetAssetID, Price: 1},
 	{Name: "Neo.Output.GetScriptHash", Func: (*interopContext).outputGetScriptHash, Price: 1},
 	{Name: "Neo.Output.GetValue", Func: (*interopContext).outputGetValue, Price: 1},
@@ -178,7 +179,6 @@ var neoInterops = []interopedFunction{
 	//		{Name: "Neo.Enumerator.Create", Func: (*interopContext).enumeratorCreate, Price: 1},
 	//		{Name: "Neo.Enumerator.Next", Func: (*interopContext).enumeratorNext, Price: 1},
 	//		{Name: "Neo.Enumerator.Value", Func: (*interopContext).enumeratorValue, Price: 1},
-	//		{Name: "Neo.InvocationTransaction.GetScript", {ic.invocationTx_GetScript, 1},
 	//		{Name: "Neo.Iterator.Concat", Func: (*interopContext).iteratorConcat, Price: 1},
 	//		{Name: "Neo.Iterator.Create", Func: (*interopContext).iteratorCreate, Price: 1},
 	//		{Name: "Neo.Iterator.Key", Func: (*interopContext).iteratorKey, Price: 1},