Refactor the code

pkg/eth/api.go

@@ -709,9 +709,6 @@ func (pea *PublicEthAPI) localGetBalance(ctx context.Context, address common.Add
 func (pea *PublicEthAPI) GetStorageAt(ctx context.Context, address common.Address, key string, blockNrOrHash rpc.BlockNumberOrHash) (hexutil.Bytes, error) {
 	storageVal, err := pea.B.GetStorageByNumberOrHash(ctx, address, common.HexToHash(key), blockNrOrHash)
 	if storageVal != nil && err == nil {
-		if len(storageVal) == 0 {
-			return make([]byte, 32), nil
-		}
 		var value common.Hash
 		_, content, _, err := rlp.Split(storageVal)
 		if err == io.ErrUnexpectedEOF {

pkg/eth/eth_state_test.go

@@ -476,16 +476,16 @@ var _ = Describe("eth state reading tests", func() {
 		It("Returns empty slice if it tries to access a contract which does not exist", func() {
 			storage, err := api.GetStorageAt(ctx, test_helpers.ContractAddr, test_helpers.ContractSlotKeyHash.Hex(), rpc.BlockNumberOrHashWithNumber(0))
 			Expect(err).NotTo(HaveOccurred())
-			Expect(storage).To(Equal(hexutil.Bytes(make([]byte, 32))))
+			Expect(storage).To(Equal(hexutil.Bytes(eth.EmptyNodeValue)))
 
 			storage, err = api.GetStorageAt(ctx, test_helpers.ContractAddr, test_helpers.ContractSlotKeyHash.Hex(), rpc.BlockNumberOrHashWithNumber(1))
 			Expect(err).NotTo(HaveOccurred())
-			Expect(storage).To(Equal(hexutil.Bytes(make([]byte, 32))))
+			Expect(storage).To(Equal(hexutil.Bytes(eth.EmptyNodeValue)))
 		})
 		It("Returns empty slice if it tries to access a contract slot which does not exist", func() {
 			storage, err := api.GetStorageAt(ctx, test_helpers.ContractAddr, randomHash.Hex(), rpc.BlockNumberOrHashWithNumber(2))
 			Expect(err).NotTo(HaveOccurred())
-			Expect(storage).To(Equal(hexutil.Bytes(make([]byte, 32))))
+			Expect(storage).To(Equal(hexutil.Bytes(eth.EmptyNodeValue)))
 		})
 		It("Retrieves the storage value at the provided contract address and storage leaf key at the block with the provided hash or number", func() {
 			// After deployment
@@ -506,7 +506,7 @@ var _ = Describe("eth state reading tests", func() {
 
 			val, err = api.GetStorageAt(ctx, test_helpers.ContractAddr, test_helpers.IndexOne, rpc.BlockNumberOrHashWithNumber(5))
 			Expect(err).ToNot(HaveOccurred())
-			Expect(val).To(Equal(hexutil.Bytes(make([]byte, 32))))
+			Expect(val).To(Equal(hexutil.Bytes(eth.EmptyNodeValue)))
 		})
 		It("Throws an error for a non-existing block hash", func() {
 			_, err := api.GetStorageAt(ctx, test_helpers.ContractAddr, test_helpers.IndexOne, rpc.BlockNumberOrHashWithHash(randomHash, true))

pkg/eth/ipld_retriever.go

@@ -152,6 +152,8 @@ const (
 																	LIMIT 1`
 )
 
+var EmptyNodeValue = make([]byte, common.HashLength)
+
 type rctIpldResult struct {
 	LeafCID string `db:"leaf_cid"`
 	Data    []byte `db:"data"`
@@ -440,7 +442,7 @@ func (r *IPLDRetriever) RetrieveAccountByAddressAndBlockHash(address common.Addr
 	}
 
 	if accountResult.NodeType == removedNode {
-		return "", []byte{}, nil
+		return "", EmptyNodeValue, nil
 	}
 
 	var i []interface{}
@@ -463,7 +465,7 @@ func (r *IPLDRetriever) RetrieveAccountByAddressAndBlockNumber(address common.Ad
 	}
 
 	if accountResult.NodeType == removedNode {
-		return "", []byte{}, nil
+		return "", EmptyNodeValue, nil
 	}
 
 	var i []interface{}
@@ -485,7 +487,7 @@ func (r *IPLDRetriever) RetrieveStorageAtByAddressAndStorageSlotAndBlockHash(add
 		return "", nil, nil, err
 	}
 	if storageResult.NodeType == removedNode {
-		return "", []byte{}, []byte{}, nil
+		return "", EmptyNodeValue, EmptyNodeValue, nil
 	}
 	var i []interface{}
 	if err := rlp.DecodeBytes(storageResult.Data, &i); err != nil {
@@ -508,7 +510,7 @@ func (r *IPLDRetriever) RetrieveStorageAtByAddressAndStorageKeyAndBlockNumber(ad
 	}
 
 	if storageResult.NodeType == removedNode {
-		return "", []byte{}, nil
+		return "", EmptyNodeValue, nil
 	}
 	var i []interface{}
 	if err := rlp.DecodeBytes(storageResult.Data, &i); err != nil {

pkg/graphql/graphql.go

@@ -18,6 +18,7 @@
 package graphql
 
 import (
+	"bytes"
 	"context"
 	"database/sql"
 	"errors"
@@ -31,6 +32,7 @@ import (
 	"github.com/ethereum/go-ethereum/eth/filters"
 	"github.com/ethereum/go-ethereum/rlp"
 	"github.com/ethereum/go-ethereum/rpc"
+
 	"github.com/vulcanize/ipld-eth-server/pkg/eth"
 )
 
@@ -1010,8 +1012,9 @@ func (r *Resolver) GetStorageAt(ctx context.Context, args struct {
 
 		return nil, err
 	}
-	if len(rlpValue) == 0 {
+
-		return &StorageResult{value: make([]byte, 32), cid: cid, ipldBlock: ipldBlock}, nil
+	if bytes.Compare(rlpValue, eth.EmptyNodeValue) == 0 {
+		return &StorageResult{value: eth.EmptyNodeValue, cid: cid, ipldBlock: ipldBlock}, nil
 	}
 
 	var value interface{}

test/integration_test.go

@@ -9,12 +9,13 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/ethclient"
 	"github.com/ethereum/go-ethereum/rlp"
 	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
-	integration "github.com/vulcanize/ipld-eth-server/test"
 
-	"github.com/ethereum/go-ethereum/ethclient"
+	"github.com/vulcanize/ipld-eth-server/pkg/eth"
+	integration "github.com/vulcanize/ipld-eth-server/test"
 )
 
 const nonExistingBlockHash = "0x111111111111111111111111111111111111111111111111111111111111111"
@@ -394,7 +395,6 @@ var _ = Describe("Integration test", func() {
 
 		It("get storage after selfdestruct", func() {
 			totalSupplyIndex := "0x2"
-			zeroHash := make([]byte, 32)
 
 			tx, err := integration.DestoyContract(contract.Address)
 			Expect(err).ToNot(HaveOccurred())
@@ -405,7 +405,7 @@ var _ = Describe("Integration test", func() {
 			Expect(err).ToNot(HaveOccurred())
 
 			Expect(gethStorage1).NotTo(Equal(gethStorage2))
-			Expect(gethStorage2).To(Equal(zeroHash))
+			Expect(gethStorage2).To(Equal(eth.EmptyNodeValue))
 
 			ipldStorage1, err := ipldClient.StorageAt(ctx, common.HexToAddress(contract.Address), common.HexToHash(totalSupplyIndex), big.NewInt(tx.BlockNumber-1))
 			Expect(err).ToNot(HaveOccurred())