Implement getAccount RPC method (#370)

ethapi/api.go

@@ -708,6 +708,53 @@ func (s *PublicBlockChainAPI) GetBalance(ctx context.Context, address common.Add
 	return (*hexutil.U256)(state.GetBalance(address)), state.Error()
 }
 
+// GetAccountResult is result struct for GetAccount.
+// The result contains:
+// 1) CodeHash - hash of the code for the given address
+// 2) StorageRoot - storage root for the given address
+// 3) Balance - the amount of wei for the given address
+// 4) Nonce - the number of transactions for given address
+type GetAccountResult struct {
+	CodeHash    common.Hash    `json:"codeHash"`
+	StorageRoot common.Hash    `json:"storageRoot"`
+	Balance     *hexutil.U256  `json:"balance"`
+	Nonce       hexutil.Uint64 `json:"nonce"`
+}
+
+// GetAccount returns the information about account with given address in the state of the given block number.
+// The rpc.LatestBlockNumber and rpc.PendingBlockNumber meta block numbers are also allowed.
+func (s *PublicBlockChainAPI) GetAccount(ctx context.Context, address common.Address, blockNrOrHash rpc.BlockNumberOrHash) (*GetAccountResult, error) {
+	state, header, err := s.b.StateAndHeaderByNumberOrHash(ctx, blockNrOrHash)
+	if err != nil {
+		return nil, err
+	}
+	defer state.Release()
+	proof, err := state.GetProof(address, nil)
+	if err != nil {
+		return nil, err
+	}
+	codeHash, _, err := proof.GetCodeHash(cc.Hash(header.Root), cc.Address(address))
+	if err != nil {
+		return nil, err
+	}
+	_, storageRoot, _ := proof.GetAccountElements(cc.Hash(header.Root), cc.Address(address))
+	balance, _, err := proof.GetBalance(cc.Hash(header.Root), cc.Address(address))
+	if err != nil {
+		return nil, err
+	}
+	nonce, _, err := proof.GetNonce(cc.Hash(header.Root), cc.Address(address))
+	if err != nil {
+		return nil, err
+	}
+	u256Balance := balance.Uint256()
+	return &GetAccountResult{
+		CodeHash:    common.Hash(codeHash),
+		StorageRoot: common.Hash(storageRoot),
+		Balance:     (*hexutil.U256)(&u256Balance),
+		Nonce:       hexutil.Uint64(nonce.ToUint64()),
+	}, state.Error()
+}
+
 // AccountResult is result struct for GetProof
 type AccountResult struct {
 	Address      common.Address  `json:"address"`

ethapi/api_test.go

@@ -9,6 +9,7 @@ import (
 	"github.com/Fantom-foundation/go-opera/inter/state"
 	"github.com/ethereum/go-ethereum/common/hexutil"
 	"github.com/stretchr/testify/require"
+	"go.uber.org/mock/gomock"
 	"math/big"
 	"testing"
 
@@ -18,7 +19,6 @@ import (
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/params"
 	"github.com/ethereum/go-ethereum/rpc"
-	gomock "go.uber.org/mock/gomock"
 )
 
 func TestGetBlockReceipts(t *testing.T) {
@@ -117,6 +117,45 @@ func TestAPI_GetProof(t *testing.T) {
 	require.Equal(t, []StorageResult{storageProof}, accountProof.StorageProof)
 }
 
+func TestAPI_GetAccount(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+
+	addr := cc.Address{1}
+	codeHash := cc.Hash{2}
+	storageRoot := cc.Hash{3}
+	balance := amount.New(4)
+	nonce := cc.ToNonce(5)
+	headerRoot := common.Hash{123}
+
+	mockBackend := NewMockBackend(ctrl)
+	mockState := state.NewMockStateDB(ctrl)
+	mockProof := witness.NewMockProof(ctrl)
+	mockHeader := &evmcore.EvmHeader{Root: headerRoot}
+
+	blkNr := rpc.BlockNumberOrHashWithNumber(rpc.LatestBlockNumber)
+
+	mockBackend.EXPECT().StateAndHeaderByNumberOrHash(gomock.Any(), blkNr).Return(mockState, mockHeader, nil)
+	mockState.EXPECT().GetProof(common.Address(addr), nil).Return(mockProof, nil)
+	mockProof.EXPECT().GetCodeHash(cc.Hash(headerRoot), addr).Return(codeHash, true, nil)
+	mockProof.EXPECT().GetAccountElements(cc.Hash(headerRoot), addr).Return(nil, storageRoot, true)
+	mockProof.EXPECT().GetBalance(cc.Hash(headerRoot), addr).Return(balance, true, nil)
+	mockProof.EXPECT().GetNonce(cc.Hash(headerRoot), addr).Return(nonce, true, nil)
+	mockState.EXPECT().Error().Return(nil)
+	mockState.EXPECT().Release()
+
+	api := NewPublicBlockChainAPI(mockBackend)
+
+	account, err := api.GetAccount(context.Background(), common.Address(addr), blkNr)
+	require.NoError(t, err, "failed to get account")
+
+	u256Balance := balance.Uint256()
+	require.Equal(t, common.Hash(codeHash), account.CodeHash)
+	require.Equal(t, common.Hash(storageRoot), account.StorageRoot)
+	require.Equal(t, (*hexutil.U256)(&u256Balance), account.Balance)
+	require.Equal(t, hexutil.Uint64(nonce.ToUint64()), account.Nonce)
+}
+
 func testGetBlockReceipts(t *testing.T, blockParam rpc.BlockNumberOrHash) ([]map[string]interface{}, error) {
 
 	ctrl := gomock.NewController(t)

tests/get_account_test.go

@@ -0,0 +1,55 @@
+package tests
+
+import (
+	"github.com/Fantom-foundation/go-opera/ethapi"
+	"github.com/Fantom-foundation/go-opera/tests/contracts/counter"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/rpc"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestGetAccount(t *testing.T) {
+	net, err := StartIntegrationTestNet(t.TempDir())
+	require.NoError(t, err, "failed to start the fake network")
+	defer net.Stop()
+
+	// Deploy the transient storage contract
+	_, deployReceipt, err := DeployContract(net, counter.DeployCounter)
+	require.NoError(t, err, "failed to deploy contract")
+
+	addr := deployReceipt.ContractAddress
+
+	c, err := net.GetClient()
+	require.NoError(t, err, "failed to get client")
+	defer c.Close()
+
+	rpcClient := c.Client()
+	defer rpcClient.Close()
+
+	var res ethapi.GetAccountResult
+	err = rpcClient.Call(&res, "eth_getAccount", addr, rpc.LatestBlockNumber)
+	require.NoError(t, err, "failed to call get account")
+
+	// Extract proof to find actual StorageHash(Root), Nonce, Balance and CodeHash
+	var proofRes struct {
+		StorageHash common.Hash
+		Nonce       hexutil.Uint64
+		Balance     *hexutil.U256
+		CodeHash    common.Hash
+	}
+	err = rpcClient.Call(
+		&proofRes,
+		"eth_getProof",
+		addr,
+		nil,
+		rpc.LatestBlockNumber,
+	)
+	require.NoError(t, err, "failed call to get proof")
+
+	require.Equal(t, proofRes.CodeHash, res.CodeHash)
+	require.Equal(t, proofRes.StorageHash, res.StorageRoot)
+	require.Equal(t, proofRes.Balance, res.Balance)
+	require.Equal(t, proofRes.Nonce, res.Nonce)
+}