native: add getCommitteeAddress method

Port neo-project/neo#3154.

Close #3334

Signed-off-by: Ekaterina Pavlova <ekt@morphbits.io>

internal/fakechain/fakechain.go

@@ -218,6 +218,11 @@ func (chain *FakeChain) GetCommittee() (keys.PublicKeys, error) {
 	panic("TODO")
 }
 
+// GetCommitteeAddress implements the Blockchainer interface.
+func (chain *FakeChain) GetCommitteeAddress() (util.Uint160, error) {
+	panic("TODO")
+}
+
 // GetContractState implements the Blockchainer interface.
 func (chain *FakeChain) GetContractState(hash util.Uint160) *state.Contract {
 	panic("TODO")

pkg/compiler/native_test.go

@@ -163,6 +163,7 @@ func TestNativeHelpersCompile(t *testing.T) {
 		{"getAllCandidates", nil},
 		{"getCandidateVote", []string{pub}},
 		{"getCommittee", nil},
+		{"getCommitteeAddress", nil},
 		{"getGasPerBlock", nil},
 		{"getNextBlockValidators", nil},
 		{"getRegisterPrice", nil},

pkg/core/native/native_neo.go

@@ -232,6 +232,10 @@ func newNEO(cfg config.ProtocolConfiguration) *NEO {
 	md = newMethodAndPrice(n.getCommittee, 1<<16, callflag.ReadStates)
 	n.AddMethod(md, desc)
 
+	desc = newDescriptor("getCommitteeAddress", smartcontract.Hash160Type)
+	md = newMethodAndPrice(n.getCommitteeAddress, 1<<16, callflag.ReadStates)
+	n.AddMethod(md, desc)
+
 	desc = newDescriptor("getNextBlockValidators", smartcontract.ArrayType)
 	md = newMethodAndPrice(n.getNextBlockValidators, 1<<16, callflag.ReadStates)
 	n.AddMethod(md, desc)
@@ -1071,6 +1075,10 @@ func (n *NEO) getCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackit
 	return stackitem.NewArray(arr)
 }
 
+func (n *NEO) getCommitteeAddress(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
+	return stackitem.NewByteArray(n.GetCommitteeAddress(ic.DAO).BytesBE())
+}
+
 func (n *NEO) getAllCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackitem.Item {
 	ctx, cancel := context.WithCancel(context.Background())
 	prefix := []byte{prefixCandidate}

pkg/core/native/native_test/neo_test.go

@@ -18,10 +18,12 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/native/nativenames"
 	"github.com/nspcc-dev/neo-go/pkg/core/state"
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
+	"github.com/nspcc-dev/neo-go/pkg/crypto/hash"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/io"
 	"github.com/nspcc-dev/neo-go/pkg/neotest"
 	"github.com/nspcc-dev/neo-go/pkg/neotest/chain"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/trigger"
 	"github.com/nspcc-dev/neo-go/pkg/util"
@@ -396,6 +398,19 @@ func TestNEO_RecursiveGASMint(t *testing.T) {
 	neoValidatorInvoker.Invoke(t, true, "transfer", e.Validator.ScriptHash(), c.Hash, int64(1), nil)
 }
 
+func TestNEO_GetCommitteeAddress(t *testing.T) {
+	neoValidatorInvoker := newNeoValidatorsClient(t)
+	e := neoValidatorInvoker.Executor
+	standByCommitteePublicKeys, err := keys.NewPublicKeysFromStrings(e.Chain.GetConfig().StandbyCommittee)
+	require.NoError(t, err)
+	sort.Sort(standByCommitteePublicKeys)
+	expectedCommitteeAddress, err := smartcontract.CreateMajorityMultiSigRedeemScript(standByCommitteePublicKeys)
+	require.NoError(t, err)
+	stack, err := neoValidatorInvoker.TestInvoke(t, "getCommitteeAddress")
+	require.NoError(t, err)
+	require.Equal(t, hash.Hash160(expectedCommitteeAddress).BytesBE(), stack.Pop().Item().Value().([]byte))
+}
+
 func TestNEO_GetAccountState(t *testing.T) {
 	neoValidatorInvoker := newNeoValidatorsClient(t)
 	e := neoValidatorInvoker.Executor

pkg/interop/native/neo/neo.go

@@ -126,3 +126,9 @@ func UnclaimedGAS(addr interop.Hash160, end int) int {
 func GetAccountState(addr interop.Hash160) *AccountState {
 	return neogointernal.CallWithToken(Hash, "getAccountState", int(contract.ReadStates), addr).(*AccountState)
 }
+
+// GetCommitteeAddress represents `getCommitteeAddress` method of NEO native contract.
+func GetCommitteeAddress() interop.Hash160 {
+	return neogointernal.CallWithToken(Hash, "getCommitteeAddress", int(contract.ReadStates)).(interop.Hash160)
+
+}

pkg/rpcclient/neo/neo.go

@@ -233,6 +233,11 @@ func (c *ContractReader) GetCommittee() (keys.PublicKeys, error) {
 	return unwrap.ArrayOfPublicKeys(c.invoker.Call(Hash, "getCommittee"))
 }
 
+// GetCommitteeAddress returns the committee address.
+func (c *ContractReader) GetCommitteeAddress() (util.Uint160, error) {
+	return unwrap.Uint160(c.invoker.Call(Hash, "getCommitteeAddress"))
+}
+
 // GetNextBlockValidators returns the list of validator keys that will sign the
 // next block. This method is mostly useful for historic invocations because the
 // RPC protocol provides direct getnextblockvalidators call that provides more