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/blockchain.go

@@ -2758,6 +2758,11 @@ func (bc *Blockchain) GetCommittee() (keys.PublicKeys, error) {
 	return pubs, nil
 }
 
+// GetCommitteeAddress returns the script hash of the committee multi-sig contract.
+func (bc *Blockchain) GetCommitteeAddress() (util.Uint160, error) {
+	return bc.contracts.NEO.GetCommitteeAddress(bc.dao), nil
+}
+
 // ComputeNextBlockValidators returns current validators. Validators list
 // returned from this method is updated once per CommitteeSize number of blocks.
 // For the last block in the dBFT epoch this method returns the list of validators

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.ArrayType)
+	md = newMethodAndPrice(n.GetCommitteeAddressCall, 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)
@@ -1051,6 +1055,9 @@ func (n *NEO) getCandidatesCall(ic *interop.Context, _ []stackitem.Item) stackit
 	return stackitem.NewArray(arr)
 }
 
+func (n *NEO) GetCommitteeAddressCall(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

@@ -331,6 +331,16 @@ 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
+	committeeAddress, err := e.Chain.GetCommitteeAddress()
+	require.NoError(t, err)
+	stack, err := neoValidatorInvoker.TestInvoke(t, "getCommitteeAddress")
+	require.NoError(t, err)
+	require.Equal(t, committeeAddress.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)
+
+}