From 4d2d20cff4606fa08e70f00def26449365ddd13f Mon Sep 17 00:00:00 2001
From: Sale Djenic <aleksandardjenic@status.im>
Date: Tue, 23 Jul 2024 12:15:29 +0200
Subject: [PATCH] fix_: allow sending 0 value transactions

---
 .../pathprocessor/processor_bridge_hop.go     |  2 +-
 services/wallet/router/router_send_type.go    | 18 +++++++
 services/wallet/router/router_v2.go           | 13 +++++
 services/wallet/router/router_v2_test_data.go | 48 +++++++++++++++++++
 4 files changed, 80 insertions(+), 1 deletion(-)

diff --git a/services/wallet/router/pathprocessor/processor_bridge_hop.go b/services/wallet/router/pathprocessor/processor_bridge_hop.go
index e8d79047e..59cf666c1 100644
--- a/services/wallet/router/pathprocessor/processor_bridge_hop.go
+++ b/services/wallet/router/pathprocessor/processor_bridge_hop.go
@@ -438,7 +438,7 @@ func (h *HopBridgeProcessor) CalculateFees(params ProcessorInputParams) (*big.In
 	// Remove token fee from bonder fee as said here:
 	// https://docs.hop.exchange/v/developer-docs/api/api#get-v1-quote
 	// `bonderFee` - The suggested bonder fee for the amount in. The bonder fee also includes the cost of the destination transaction fee.
-	tokenFee := ZeroBigIntValue //new(big.Int).Sub(h.bonderFee.AmountIn.Int, h.bonderFee.EstimatedRecieved.Int)
+	tokenFee := new(big.Int).Sub(bonderFee.AmountIn.Int, bonderFee.EstimatedRecieved.Int)
 
 	return bonderFee.BonderFee.Int, tokenFee, nil
 }
diff --git a/services/wallet/router/router_send_type.go b/services/wallet/router/router_send_type.go
index e5c670ac5..4a4f1fc85 100644
--- a/services/wallet/router/router_send_type.go
+++ b/services/wallet/router/router_send_type.go
@@ -133,6 +133,24 @@ func (s SendType) canUseProcessor(p pathprocessor.PathProcessor) bool {
 	}
 }
 
+func (s SendType) processZeroAmountInProcessor(amountIn *big.Int, amountOut *big.Int, processorName string) bool {
+	if amountIn.Cmp(pathprocessor.ZeroBigIntValue) == 0 {
+		if s == Transfer {
+			if processorName != pathprocessor.ProcessorTransferName {
+				return false
+			}
+		} else if s == Swap {
+			if amountOut.Cmp(pathprocessor.ZeroBigIntValue) == 0 {
+				return false
+			}
+		} else {
+			return false
+		}
+	}
+
+	return true
+}
+
 func (s SendType) isAvailableBetween(from, to *params.Network) bool {
 	if s.IsCollectiblesTransfer() ||
 		s.IsEnsTransfer() ||
diff --git a/services/wallet/router/router_v2.go b/services/wallet/router/router_v2.go
index c4c5e7f63..1a80a59f4 100644
--- a/services/wallet/router/router_v2.go
+++ b/services/wallet/router/router_v2.go
@@ -638,6 +638,15 @@ func (r *Router) getCrossChainsOptionsForSendingAmount(input *RouteInputParams,
 
 		amountLocked := false
 		amountToSend := input.AmountIn.ToInt()
+
+		if amountToSend.Cmp(pathprocessor.ZeroBigIntValue) == 0 {
+			finalCrossChainAmountOptions[selectedFromChain.ChainID] = append(finalCrossChainAmountOptions[selectedFromChain.ChainID], amountOption{
+				amount: amountToSend,
+				locked: false,
+			})
+			continue
+		}
+
 		lockedAmount, fromChainLocked := input.FromLockedAmount[selectedFromChain.ChainID]
 		if fromChainLocked {
 			amountToSend = lockedAmount.ToInt()
@@ -826,6 +835,10 @@ func (r *Router) resolveCandidates(ctx context.Context, input *RouteInputParams,
 						continue
 					}
 
+					if !input.SendType.processZeroAmountInProcessor(amountOption.amount, input.AmountOut.ToInt(), pProcessor.Name()) {
+						continue
+					}
+
 					for _, dest := range selectedTohains {
 
 						if !input.SendType.isAvailableFor(network) {
diff --git a/services/wallet/router/router_v2_test_data.go b/services/wallet/router/router_v2_test_data.go
index c2541bad0..75e5780c3 100644
--- a/services/wallet/router/router_v2_test_data.go
+++ b/services/wallet/router/router_v2_test_data.go
@@ -207,6 +207,54 @@ type normalTestParams struct {
 
 func getNormalTestParamsList() []normalTestParams {
 	return []normalTestParams{
+		{
+			name: "ETH transfer - No Specific FromChain - No Specific ToChain - 0 AmountIn",
+			input: &RouteInputParams{
+				testnetMode: false,
+				Uuid:        uuid.NewString(),
+				SendType:    Transfer,
+				AddrFrom:    common.HexToAddress("0x1"),
+				AddrTo:      common.HexToAddress("0x2"),
+				AmountIn:    (*hexutil.Big)(big.NewInt(0)),
+				TokenID:     pathprocessor.EthSymbol,
+
+				testsMode: true,
+				testParams: &routerTestParams{
+					tokenFrom: &token.Token{
+						ChainID:  1,
+						Symbol:   pathprocessor.EthSymbol,
+						Decimals: 18,
+					},
+					tokenPrices:           testTokenPrices,
+					suggestedFees:         testSuggestedFees,
+					balanceMap:            testBalanceMapPerChain,
+					estimationMap:         testEstimationMap,
+					bonderFeeMap:          testBbonderFeeMap,
+					approvalGasEstimation: testApprovalGasEstimation,
+					approvalL1Fee:         testApprovalL1Fee,
+				},
+			},
+			expectedCandidates: []*PathV2{
+				{
+					ProcessorName:    pathprocessor.ProcessorTransferName,
+					FromChain:        &mainnet,
+					ToChain:          &mainnet,
+					ApprovalRequired: false,
+				},
+				{
+					ProcessorName:    pathprocessor.ProcessorTransferName,
+					FromChain:        &optimism,
+					ToChain:          &optimism,
+					ApprovalRequired: false,
+				},
+				{
+					ProcessorName:    pathprocessor.ProcessorTransferName,
+					FromChain:        &arbitrum,
+					ToChain:          &arbitrum,
+					ApprovalRequired: false,
+				},
+			},
+		},
 		{
 			name: "ETH transfer - No Specific FromChain - No Specific ToChain",
 			input: &RouteInputParams{