verify contract when binding (#13613)

* verify contract when binding

* fix tests that rely on Bind

* fix len check

* change error to custom error

* add error test

core/services/relay/evm/chain_reader_test.go

@@ -12,6 +12,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind/backends"
+	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/jmoiron/sqlx"
@@ -145,6 +146,18 @@ func TestChainReader(t *testing.T) {
 	it := &EVMChainReaderInterfaceTester[*testing.T]{Helper: &helper{}}
 	RunChainReaderEvmTests(t, it)
 	RunChainReaderInterfaceTests[*testing.T](t, commontestutils.WrapChainReaderTesterForLoop(it))
+
+	t.Run("Bind returns error on missing contract at address", func(t *testing.T) {
+		t.Parallel()
+		it.Setup(t)
+
+		addr := common.BigToAddress(big.NewInt(42))
+		reader := it.GetChainReader(t)
+
+		err := reader.Bind(context.Background(), []clcommontypes.BoundContract{{Name: AnyContractName, Address: addr.Hex(), Pending: true}})
+
+		require.ErrorIs(t, err, evm.NoContractExistsError{Address: addr})
+	})
 }
 
 type helper struct {

core/services/relay/evm/method_binding.go

@@ -13,6 +13,14 @@ import (
 	evmclient "github.com/smartcontractkit/chainlink/v2/core/chains/evm/client"
 )
 
+type NoContractExistsError struct {
+	Address common.Address
+}
+
+func (e NoContractExistsError) Error() string {
+	return fmt.Sprintf("contract does not exist at address: %s", e.Address)
+}
+
 type methodBinding struct {
 	address      common.Address
 	contractName string
@@ -28,9 +36,22 @@ func (m *methodBinding) SetCodec(codec commontypes.RemoteCodec) {
 	m.codec = codec
 }
 
-func (m *methodBinding) Bind(_ context.Context, binding commontypes.BoundContract) error {
-	m.address = common.HexToAddress(binding.Address)
+func (m *methodBinding) Bind(ctx context.Context, binding commontypes.BoundContract) error {
+	addr := common.HexToAddress(binding.Address)
+
+	// check for contract byte code at the latest block and provided address
+	byteCode, err := m.client.CodeAt(ctx, addr, nil)
+	if err != nil {
+		return err
+	}
+
+	if len(byteCode) == 0 {
+		return NoContractExistsError{Address: addr}
+	}
+
+	m.address = addr
 	m.bound = true
+
 	return nil
 }
 

core/services/relay/evm/write_target_test.go

@@ -44,6 +44,7 @@ func TestEvmWrite(t *testing.T) {
 		mockCall = append(mockCall, byte(0))
 	}
 	evmClient.On("CallContract", mock.Anything, mock.Anything, mock.Anything).Return(mockCall, nil).Maybe()
+	evmClient.On("CodeAt", mock.Anything, mock.Anything, mock.Anything).Return([]byte("test"), nil)
 
 	chain.On("ID").Return(big.NewInt(11155111))
 	chain.On("TxManager").Return(txManager)