fix: check if the orderer has sufficient balance to make an order

Note that there already exists such check.
This commit fixes the problem when the orderer has less balances
than the offer coin, but has enough balances to make the order.
Since this fix, orders cannot make an order with too much offer coin.

x/liquidity/keeper/swap.go

@@ -16,6 +16,13 @@ import (
 // ValidateMsgLimitOrder validates types.MsgLimitOrder with state and returns
 // calculated offer coin and price that is fit into ticks.
 func (k Keeper) ValidateMsgLimitOrder(ctx sdk.Context, msg *types.MsgLimitOrder) (offerCoin sdk.Coin, price sdk.Dec, err error) {
+	spendable := k.bankKeeper.SpendableCoins(ctx, msg.GetOrderer())
+	if spendableAmt := spendable.AmountOf(msg.OfferCoin.Denom); spendableAmt.LT(msg.OfferCoin.Amount) {
+		return sdk.Coin{}, sdk.Dec{}, sdkerrors.Wrapf(
+			sdkerrors.ErrInsufficientFunds, "%s is smaller than %s",
+			sdk.NewCoin(msg.OfferCoin.Denom, spendableAmt), msg.OfferCoin)
+	}
+
 	params := k.GetParams(ctx)
 
 	if msg.OrderLifespan > params.MaxOrderLifespan {
@@ -122,6 +129,13 @@ func (k Keeper) LimitOrder(ctx sdk.Context, msg *types.MsgLimitOrder) (types.Ord
 // ValidateMsgMarketOrder validates types.MsgMarketOrder with state and returns
 // calculated offer coin and price.
 func (k Keeper) ValidateMsgMarketOrder(ctx sdk.Context, msg *types.MsgMarketOrder) (offerCoin sdk.Coin, price sdk.Dec, err error) {
+	spendable := k.bankKeeper.SpendableCoins(ctx, msg.GetOrderer())
+	if spendableAmt := spendable.AmountOf(msg.OfferCoin.Denom); spendableAmt.LT(msg.OfferCoin.Amount) {
+		return sdk.Coin{}, sdk.Dec{}, sdkerrors.Wrapf(
+			sdkerrors.ErrInsufficientFunds, "%s is smaller than %s",
+			sdk.NewCoin(msg.OfferCoin.Denom, spendableAmt), msg.OfferCoin)
+	}
+
 	params := k.GetParams(ctx)
 
 	if msg.OrderLifespan > params.MaxOrderLifespan {

x/liquidity/keeper/swap_test.go

@@ -4,6 +4,7 @@ import (
 	"time"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 
 	utils "github.com/cosmosquad-labs/squad/types"
 	"github.com/cosmosquad-labs/squad/x/liquidity"
@@ -113,6 +114,23 @@ func (s *KeeperTestSuite) TestLimitOrder() {
 	}
 }
 
+func (s *KeeperTestSuite) TestLimitOrderInsufficientOfferCoin() {
+	pair := s.createPair(s.addr(0), "denom1", "denom2", true)
+
+	orderer := s.addr(1)
+	s.fundAddr(orderer, utils.ParseCoins("1000000denom2"))
+	_, err := s.keeper.LimitOrder(s.ctx, types.NewMsgLimitOrder(
+		orderer, pair.Id, types.OrderDirectionBuy, utils.ParseCoin("1000001denom2"), "denom1",
+		utils.ParseDec("1.0"), sdk.NewInt(1000000), 0))
+	s.Require().ErrorIs(err, sdkerrors.ErrInsufficientFunds)
+
+	s.fundAddr(orderer, utils.ParseCoins("1000000denom1"))
+	_, err = s.keeper.LimitOrder(s.ctx, types.NewMsgLimitOrder(
+		orderer, pair.Id, types.OrderDirectionSell, utils.ParseCoin("1000001denom1"), "denom2",
+		utils.ParseDec("1.0"), sdk.NewInt(1000000), 0))
+	s.Require().ErrorIs(err, sdkerrors.ErrInsufficientFunds)
+}
+
 func (s *KeeperTestSuite) TestLimitOrderRefund() {
 	pair := s.createPair(s.addr(0), "denom1", "denom2", true)
 	orderer := s.addr(1)
@@ -196,6 +214,23 @@ func (s *KeeperTestSuite) TestMarketOrder() {
 	s.Require().True(coinsEq(utils.ParseCoins("10800denom2"), s.getBalances(s.addr(4))))
 }
 
+func (s *KeeperTestSuite) TestMarketOrderInsufficientOfferCoin() {
+	pair := s.createPair(s.addr(0), "denom1", "denom2", true)
+
+	orderer := s.addr(1)
+	s.fundAddr(orderer, utils.ParseCoins("1000000denom2"))
+	_, err := s.keeper.MarketOrder(s.ctx, types.NewMsgMarketOrder(
+		orderer, pair.Id, types.OrderDirectionBuy, utils.ParseCoin("1000001denom2"), "denom1",
+		sdk.NewInt(1000000), 0))
+	s.Require().ErrorIs(err, sdkerrors.ErrInsufficientFunds)
+
+	s.fundAddr(orderer, utils.ParseCoins("1000000denom1"))
+	_, err = s.keeper.MarketOrder(s.ctx, types.NewMsgMarketOrder(
+		orderer, pair.Id, types.OrderDirectionSell, utils.ParseCoin("1000001denom1"), "denom2",
+		sdk.NewInt(1000000), 0))
+	s.Require().ErrorIs(err, sdkerrors.ErrInsufficientFunds)
+}
+
 func (s *KeeperTestSuite) TestMarketOrderRefund() {
 	pair := s.createPair(s.addr(0), "denom1", "denom2", true)
 	p := utils.ParseDec("1.0")