manifest: add ABI validity check

Some methods must be defined in a valid ABI. Refs. neo-project/neo#2263.

pkg/core/native/management_test.go

@@ -8,6 +8,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/interop"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/storage"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/nef"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -23,6 +24,11 @@ func TestDeployGetUpdateDestroyContract(t *testing.T) {
 	ne, err := nef.NewFile(script)
 	require.NoError(t, err)
 	manif := manifest.NewManifest("Test")
+	manif.ABI.Methods = append(manif.ABI.Methods, manifest.Method{
+		Name:       "dummy",
+		ReturnType: smartcontract.VoidType,
+		Parameters: []manifest.Parameter{},
+	})
 
 	h := state.CreateContractHash(sender, ne.Checksum, manif.Name)
 

pkg/smartcontract/manifest/abi.go

@@ -49,6 +49,14 @@ func (a *ABI) GetEvent(name string) *Event {
 	return nil
 }
 
+// IsValid checks ABI consistency and correctness.
+func (a *ABI) IsValid() error {
+	if len(a.Methods) == 0 {
+		return errors.New("ABI contains no methods")
+	}
+	return nil
+}
+
 // ToStackItem converts ABI to stackitem.Item.
 func (a *ABI) ToStackItem() stackitem.Item {
 	methods := make([]stackitem.Item, len(a.Methods))

pkg/smartcontract/manifest/manifest.go

@@ -70,9 +70,15 @@ func (m *Manifest) CanCall(hash util.Uint160, toCall *Manifest, method string) b
 	return false
 }
 
-// IsValid checks whether the hash given is correct wrt manifest's groups.
+// IsValid checks manifest internal consistency and correctness, one of the
+// checks is for group signature correctness, contract hash is passed for it.
 func (m *Manifest) IsValid(hash util.Uint160) error {
 	var err error
+
+	err = m.ABI.IsValid()
+	if err != nil {
+		return err
+	}
 	for _, g := range m.Groups {
 		err = g.IsValid(hash)
 		if err != nil {

pkg/smartcontract/manifest/manifest_test.go

@@ -111,6 +111,16 @@ func TestIsValid(t *testing.T) {
 	contractHash := util.Uint160{1, 2, 3}
 	m := NewManifest("Test")
 
+	t.Run("invalid, no ABI methods", func(t *testing.T) {
+		require.Error(t, m.IsValid(contractHash))
+	})
+
+	m.ABI.Methods = append(m.ABI.Methods, Method{
+		Name:       "dummy",
+		ReturnType: smartcontract.VoidType,
+		Parameters: []Parameter{},
+	})
+
 	t.Run("valid, no groups", func(t *testing.T) {
 		require.NoError(t, m.IsValid(contractHash))
 	})