check division by zero and handle default values for balancer

x/move/keeper/balancer.go

@@ -228,7 +228,7 @@ func (k BalancerKeeper) poolBalances(ctx context.Context, metadataLP vmtypes.Acc
 	})
 
 	if err != nil && errors.Is(err, collections.ErrNotFound) {
-		return nil, nil
+		return []math.Int{math.ZeroInt(), math.ZeroInt()}, nil
 	} else if err != nil {
 		return nil, err
 	}
@@ -269,7 +269,7 @@ func (k BalancerKeeper) poolWeights(
 		TypeArgs: []vmtypes.TypeTag{},
 	})
 	if err != nil && errors.Is(err, collections.ErrNotFound) {
-		return nil, nil
+		return []math.LegacyDec{math.LegacyZeroDec(), math.LegacyZeroDec()}, nil
 	} else if err != nil {
 		return nil, err
 	}

x/move/keeper/dex.go

@@ -6,6 +6,7 @@ import (
 	"cosmossdk.io/math"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/pkg/errors"
 
 	distrtypes "github.com/initia-labs/initia/x/distribution/types"
 	"github.com/initia-labs/initia/x/move/types"
@@ -194,6 +195,9 @@ func (k DexKeeper) GasPrices(
 		if err != nil {
 			return true, err
 		}
+		if baseSpotPrice.IsZero() {
+			return true, errors.New("baseSpotPrice is zero")
+		}
 
 		gasPrice := baseGasPrice.Quo(baseSpotPrice)
 		gasPrices = gasPrices.Add(sdk.NewDecCoinFromDec(denomQuote, gasPrice))
@@ -220,6 +224,9 @@ func (k DexKeeper) GasPrice(
 	if err != nil {
 		return sdk.NewDecCoin(denomQuote, math.ZeroInt()), err
 	}
+	if baseSpotPrice.IsZero() {
+		return sdk.NewDecCoin(denomQuote, math.ZeroInt()), errors.New("baseSpotPrice is zero")
+	}
 
 	return sdk.NewDecCoinFromDec(denomQuote, baseGasPrice.Quo(baseSpotPrice)), nil
 }

x/move/types/connector.go

@@ -431,6 +431,10 @@ func GetBaseSpotPrice(
 	balanceBase, balanceQuote math.Int,
 	weightBase, weightQuote math.LegacyDec,
 ) math.LegacyDec {
+	if balanceBase.IsZero() || balanceQuote.IsZero() {
+		return math.LegacyZeroDec()
+	}
+
 	numerator := weightQuote.MulInt(balanceBase)
 	denominator := weightBase.MulInt(balanceQuote)