From ca3ae28f4625f9b788079b4bd9d6456584174aa2 Mon Sep 17 00:00:00 2001
From: Eduard S <eduard@iden3.io>
Date: Wed, 30 Sep 2020 11:58:31 +0200
Subject: [PATCH] Add missing error handling

---
 eth/auction.go   |  8 +++++---
 eth/ethereum.go  |  3 +++
 eth/main_test.go | 10 ++++++++--
 eth/wdelayer.go  |  8 +++++---
 4 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/eth/auction.go b/eth/auction.go
index 27d07ce..d2cccb8 100644
--- a/eth/auction.go
+++ b/eth/auction.go
@@ -958,7 +958,9 @@ var (
 	logHEZClaimed            = crypto.Keccak256Hash([]byte("HEZClaimed(address,uint128)"))
 )
 
-// AuctionEventsByBlock returns the events in a block that happened in the Auction Smart Contract
+// AuctionEventsByBlock returns the events in a block that happened in the
+// Auction Smart Contract and the blockHash where the eents happened.  If there
+// are no events in that block, blockHash is nil.
 func (c *AuctionClient) AuctionEventsByBlock(blockNum int64) (*AuctionEvents, *ethCommon.Hash, error) {
 	var auctionEvents AuctionEvents
 	var blockHash ethCommon.Hash
@@ -974,14 +976,14 @@ func (c *AuctionClient) AuctionEventsByBlock(blockNum int64) (*AuctionEvents, *e
 
 	logs, err := c.client.client.FilterLogs(context.TODO(), query)
 	if err != nil {
-		fmt.Println(err)
+		return nil, nil, err
 	}
 	if len(logs) > 0 {
 		blockHash = logs[0].BlockHash
 	}
 	for _, vLog := range logs {
 		if vLog.BlockHash != blockHash {
-			return nil, nil, err
+			return nil, nil, ErrBlockHashMismatchEvent
 		}
 		switch vLog.Topics[0] {
 		case logNewBid:
diff --git a/eth/ethereum.go b/eth/ethereum.go
index 711e4c9..89617f8 100644
--- a/eth/ethereum.go
+++ b/eth/ethereum.go
@@ -30,6 +30,9 @@ var (
 	ErrReceiptStatusFailed = fmt.Errorf("receipt status is failed")
 	// ErrReceiptNotReceived is used when unable to retrieve a transaction
 	ErrReceiptNotReceived = fmt.Errorf("receipt not available")
+	// ErrBlockHashMismatchEvent is used when there's a block hash mismatch
+	// beetween different events of the same block
+	ErrBlockHashMismatchEvent = fmt.Errorf("block hash mismatch in event log")
 )
 
 const (
diff --git a/eth/main_test.go b/eth/main_test.go
index 2fba7eb..63589b7 100644
--- a/eth/main_test.go
+++ b/eth/main_test.go
@@ -126,9 +126,15 @@ func TestMain(m *testing.M) {
 		// Controllable Governance Address
 
 		ethereumClientGov := NewEthereumClient(ethClient, accountGov, ks, nil)
-		auctionClient, _ = NewAuctionClient(ethereumClientGov, auctionAddressConst, tokenHezAddressConst)
+		auctionClient, err = NewAuctionClient(ethereumClientGov, auctionAddressConst, tokenHezAddressConst)
+		if err != nil {
+			panic(err)
+		}
 		rollupClient = NewRollupClient(ethereumClientGov, hermezRollupAddressConst)
-		wdelayerClient, _ = NewWDelayerClient(ethereumClientGov, wdelayerAddressConst)
+		wdelayerClient, err = NewWDelayerClient(ethereumClientGov, wdelayerAddressConst)
+		if err != nil {
+			panic(err)
+		}
 
 		ethereumClientKep = NewEthereumClient(ethClient, accountKep, ks, nil)
 		ethereumClientWhite = NewEthereumClient(ethClient, accountWhite, ks, nil)
diff --git a/eth/wdelayer.go b/eth/wdelayer.go
index 43584ea..b89bb68 100644
--- a/eth/wdelayer.go
+++ b/eth/wdelayer.go
@@ -430,7 +430,9 @@ var (
 	logNewHermezGovernanceDAOAddress = crypto.Keccak256Hash([]byte("NewHermezGovernanceDAOAddress(address)"))
 )
 
-// WDelayerEventsByBlock returns the events in a block that happened in the WDelayer Smart Contract
+// WDelayerEventsByBlock returns the events in a block that happened in the
+// WDelayer Smart Contract and the blockHash where the eents happened.  If
+// there are no events in that block, blockHash is nil.
 func (c *WDelayerClient) WDelayerEventsByBlock(blockNum int64) (*WDelayerEvents, *ethCommon.Hash, error) {
 	var wdelayerEvents WDelayerEvents
 	var blockHash ethCommon.Hash
@@ -447,14 +449,14 @@ func (c *WDelayerClient) WDelayerEventsByBlock(blockNum int64) (*WDelayerEvents,
 
 	logs, err := c.client.client.FilterLogs(context.Background(), query)
 	if err != nil {
-		fmt.Println(err)
+		return nil, nil, err
 	}
 	if len(logs) > 0 {
 		blockHash = logs[0].BlockHash
 	}
 	for _, vLog := range logs {
 		if vLog.BlockHash != blockHash {
-			return nil, nil, err
+			return nil, nil, ErrBlockHashMismatchEvent
 		}
 		switch vLog.Topics[0] {
 		case logDeposit: