make deposit and withdraw fail with amount 0

precompiles/bank/method_deposit.go

@@ -142,7 +142,7 @@ func unpackDepositArgs(args []interface{}) (zrc20Addr common.Address, amount *bi
  }
 
  amount, ok = args[1].(*big.Int)
- if !ok || amount.Sign() < 0 || amount == nil || amount == new(big.Int) {
+ if !ok || amount.Sign() <= 0 || amount == nil || amount == new(big.Int) {
  return common.Address{}, nil, &ptypes.ErrInvalidAmount{
  Got: amount.String(),
  }

precompiles/bank/method_test.go

@@ -130,18 +130,12 @@ func Test_Methods(t *testing.T) {
  ts.mockVMContract.Input = packInputArgs(
  t,
  methodID,
- []interface{}{ts.zrc20Address, big.NewInt(0)}...,
+ []interface{}{ts.zrc20Address, big.NewInt(1000)}...,
  )
 
  success, err := ts.bankContract.Run(ts.mockEVM, ts.mockVMContract, false)
  require.Error(t, err)
- require.ErrorAs(
- t,
- ptypes.ErrInvalidCoin{
- Empty: true,
- },
- err,
- )
+ require.Contains(t, err.Error(), "invalid allowance, got: 0")
 
  res, err := ts.bankABI.Methods[DepositMethodName].Outputs.Unpack(success)
  require.NoError(t, err)
@@ -150,6 +144,33 @@ func Test_Methods(t *testing.T) {
  require.False(t, ok)
  })
 
+ t.Run("should fail when trying to deposit 0", func(t *testing.T) {
+ ts := setupChain(t)
+ caller := fungibletypes.ModuleAddressZEVM
+ ts.fungibleKeeper.DepositZRC20(ts.ctx, ts.zrc20Address, caller, big.NewInt(1000))
+
+ methodID := ts.bankABI.Methods[DepositMethodName]
+
+ // Allow bank to spend 500 ZRC20 tokens.
+ allowBank(t, ts, big.NewInt(500))
+
+ // Set CallerAddress and evm.Origin to the caller address.
+ // Caller does not have any balance, and bank does not have any allowance.
+ ts.mockVMContract.CallerAddress = caller
+ ts.mockEVM.Origin = caller
+
+ // Set the input arguments for the deposit method.
+ ts.mockVMContract.Input = packInputArgs(
+ t,
+ methodID,
+ []interface{}{ts.zrc20Address, big.NewInt(0)}...,
+ )
+
+ _, err := ts.bankContract.Run(ts.mockEVM, ts.mockVMContract, false)
+ require.Error(t, err)
+ require.Contains(t, err.Error(), "invalid token amount: 0")
+ })
+
  t.Run("should fail when trying to deposit more than allowed to bank", func(t *testing.T) {
  ts := setupChain(t)
  caller := fungibletypes.ModuleAddressZEVM

precompiles/bank/method_withdraw.go

@@ -134,7 +134,7 @@ func unpackWithdrawArgs(args []interface{}) (zrc20Addr common.Address, amount *b
  }
 
  amount, ok = args[1].(*big.Int)
- if !ok || amount.Sign() < 0 || amount == nil || amount == new(big.Int) {
+ if !ok || amount.Sign() <= 0 || amount == nil || amount == new(big.Int) {
  return common.Address{}, nil, &ptypes.ErrInvalidAmount{
  Got: amount.String(),
  }