From 977f122eb39e23a5a98d9692a3c79aa86463f801 Mon Sep 17 00:00:00 2001
From: Francisco de Borja Aranda Castillejo <me@fbac.dev>
Date: Wed, 11 Sep 2024 19:24:23 +0200
Subject: [PATCH] expand e2e

---
 e2e/e2etests/test_precompiles_bank.go | 46 ++++++++++++++++++++-------
 precompiles/bank/call_contract.go     | 28 ++++++----------
 2 files changed, 44 insertions(+), 30 deletions(-)

diff --git a/e2e/e2etests/test_precompiles_bank.go b/e2e/e2etests/test_precompiles_bank.go
index 0b2cb0e99c..59320d07c6 100644
--- a/e2e/e2etests/test_precompiles_bank.go
+++ b/e2e/e2etests/test_precompiles_bank.go
@@ -3,6 +3,7 @@ package e2etests
 import (
 	"math/big"
 
+	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/stretchr/testify/require"
 
 	"github.com/zeta-chain/node/e2e/runner"
@@ -13,28 +14,49 @@ import (
 func TestPrecompilesBank(r *runner.E2ERunner, args []string) {
 	require.Len(r, args, 0, "No arguments expected")
 
+	owner, spender := r.ZEVMAuth.From, bank.ContractAddress
+
 	bankContract, err := bank.NewIBank(bank.ContractAddress, r.ZEVMClient)
 	require.NoError(r, err, "Failed to create bank contract caller")
 
-	// Get the balance of the user_precompile in coins "zevm/0x12345"
+	// Get the initial balance of the owner in ERC20ZRC20 tokens.
+	ownerERC20InitialBalance, err := r.ERC20ZRC20.BalanceOf(&bind.CallOpts{}, owner)
+	require.NoError(r, err, "Error retrieving initial owner balance")
+
+	// Get the balance of the owner in coins "zevm/0x12345".
 	// BalanceOf will convert the ZRC20 address to a Cosmos denom formatted as "zevm/0x12345".
-	retBalanceOf, err := bankContract.BalanceOf(nil, r.ERC20ZRC20Addr, r.ZEVMAuth.From)
-	require.NoError(r, err, "Error calling balanceOf")
+	retBalanceOf, err := bankContract.BalanceOf(nil, r.ERC20ZRC20Addr, owner)
+	require.NoError(r, err, "Error calling bank.balanceOf")
 	require.EqualValues(r, uint64(0), retBalanceOf.Uint64(), "balanceOf result has to be 0")
 
-	// Allow the bank contract to spend 100 coins
-	tx, err := r.ERC20ZRC20.Approve(r.ZEVMAuth, bank.ContractAddress, big.NewInt(100))
-	require.NoError(r, err, "Error approving bank contract")
+	// Allow the bank contract to spend 100 ERC20ZRC20 tokens.
+	tx, err := r.ERC20ZRC20.Approve(r.ZEVMAuth, spender, big.NewInt(100))
+	require.NoError(r, err, "Error approving allowance for bank contract")
 
 	receipt := utils.MustWaitForTxReceipt(r.Ctx, r.ZEVMClient, tx, r.Logger, r.ReceiptTimeout)
-	require.EqualValues(r, 1, receipt.Status, "Error approving allowance for bank contract")
+	require.EqualValues(r, 1, receipt.Status, "Error in the approve allowance transaction")
+
+	// Check the allowance of the bank in ERC20ZRC20 tokens. Should be 100.
+	balance, err := r.ERC20ZRC20.Allowance(&bind.CallOpts{}, owner, spender)
+	require.NoError(r, err, "Error retrieving bank allowance")
+	require.EqualValues(r, uint64(100), balance.Uint64(), "Error allowance for bank contract")
 
-	// Call deposit with 100 coins
+	// Call deposit with 100 coins.
 	_, err = bankContract.Deposit(r.ZEVMAuth, r.ERC20ZRC20Addr, big.NewInt(100))
 	require.NoError(r, err, "Error calling deposit")
 
-	// Check the balance of the user_precompile in coins "zevm/0x12345"
-
-	// Check the balance of the user_precompile in r.ERC20ZRC20Addr
-
+	// Check the balance of the owner in coins "zevm/0x12345".
+	retBalanceOf, err = bankContract.BalanceOf(nil, r.ERC20ZRC20Addr, owner)
+	require.NoError(r, err, "Error calling balanceOf")
+	require.EqualValues(r, uint64(100), retBalanceOf.Uint64(), "balanceOf result has to be 0")
+
+	// Check the balance of the owner in r.ERC20ZRC20Addr, should be 100 less.
+	ownerERC20FinalBalance, err := r.ERC20ZRC20.BalanceOf(&bind.CallOpts{}, owner)
+	require.NoError(r, err, "Error retrieving bank allowance")
+	require.EqualValues(
+		r,
+		ownerERC20InitialBalance.Uint64()-100, // expected
+		ownerERC20FinalBalance.Uint64(),       // actual
+		"Error allowance for bank contract",
+	)
 }
diff --git a/precompiles/bank/call_contract.go b/precompiles/bank/call_contract.go
index 9b7e825491..8277f96b8a 100644
--- a/precompiles/bank/call_contract.go
+++ b/precompiles/bank/call_contract.go
@@ -19,25 +19,17 @@ func (c *Contract) CallContract(
 	method string,
 	args []interface{},
 ) ([]interface{}, error) {
-	input, err := abi.Methods[method].Inputs.Pack(args)
-	if err != nil {
-		return nil, &ptypes.ErrUnexpected{
-			When: "Pack " + method,
-			Got:  err.Error(),
-		}
-	}
-
 	res, err := c.fungibleKeeper.CallEVM(
-		ctx,
-		*abi,
-		ContractAddress,
-		dst,
-		big.NewInt(0),
-		nil,
-		true,
-		false,
-		method,
-		input,
+		ctx,             // ctx
+		*abi,            // abi
+		ContractAddress, // from
+		dst,             // to
+		big.NewInt(0),   // value
+		nil,             // gasLimit
+		true,            // commit
+		false,           // noEthereumTxEvent
+		method,          // method
+		args...,         // args
 	)
 	if err != nil {
 		return nil, &ptypes.ErrUnexpected{