feat: fix division by zero issue (#808)

* feat: fix division by zero issue * feat: add error * add test
elys-network · Sep 24, 2024 · 34798ce · 34798ce
1 parent ca364fc
commit 34798ce
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Showing 4 changed files with 55 additions and 1 deletion.
diff --git a/x/amm/types/calc_in_amt_given_out.go b/x/amm/types/calc_in_amt_given_out.go
@@ -68,6 +68,9 @@ func (p Pool) CalcInAmtGivenOut(
 	}
 
 	amountInWithoutSlippage := sdk.NewDecFromInt(tokenOut.Amount).Quo(rate)
+	if tokenAmountIn.IsZero(){
+		return sdk.Coin{}, sdk.ZeroDec(), ErrAmountTooLow
+	} 
 	slippage = sdk.OneDec().Sub(amountInWithoutSlippage.Quo(tokenAmountIn))
 
 	// Ensure (1 - swapfee) is not zero to avoid division by zero

diff --git a/x/amm/types/calc_out_amt_given_in.go b/x/amm/types/calc_out_amt_given_in.go
@@ -65,6 +65,9 @@ func (p Pool) CalcOutAmtGivenIn(
 	if err != nil {
 		return sdk.Coin{}, sdk.ZeroDec(), err
 	}
+	if tokenAmountOut.IsZero(){
+		return sdk.Coin{}, sdk.ZeroDec(), ErrAmountTooLow
+	} 
 
 	rate, err := p.GetTokenARate(ctx, oracle, snapshot, tokenIn.Denom, tokenOutDenom, accountedPool)
 	if err != nil {
@@ -77,7 +80,7 @@ func (p Pool) CalcOutAmtGivenIn(
 	if amountOutWithoutSlippage.IsZero() {
 		return sdk.Coin{}, sdk.ZeroDec(), errorsmod.Wrapf(ErrInvalidMathApprox, "amount out without slippage must be positive")
 	}
-
+	
 	slippage := sdk.OneDec().Sub(tokenAmountOut.Quo(amountOutWithoutSlippage))
 
 	// We ignore the decimal component, as we round down the token amount out.

diff --git a/x/amm/types/swap_in_amt_given_out_test.go b/x/amm/types/swap_in_amt_given_out_test.go
@@ -159,6 +159,29 @@ func (suite *TestSuite) TestSwapInAmtGivenOut() {
 			expTokenIn:             sdk.NewInt64Coin(ptypes.BaseCurrency, 36075037),
 			expErr:                 false,
 		},
+
+		{
+			desc: "tokenOut is zero",
+			poolAssets: []types.PoolAsset{
+				{
+					Token:  sdk.NewInt64Coin(ptypes.BaseCurrency, 500_000_000),
+					Weight: sdk.NewInt(50),
+				},
+				{
+					Token:  sdk.NewInt64Coin("uusdt", 1500_000_000),
+					Weight: sdk.NewInt(50),
+				},
+			},
+			useOracle:              false,
+			externalLiquidityRatio: sdk.NewDec(10),
+			thresholdWeightDiff:    sdk.NewDecWithPrec(20, 2),
+			tokenOut:               sdk.NewInt64Coin("uusdt", 0),
+			inTokenDenom:           ptypes.BaseCurrency,
+			swapFee:                sdk.NewDecWithPrec(1, 2),
+			expRecoveryBonus:       sdk.ZeroDec(),
+			expTokenIn:             sdk.NewInt64Coin(ptypes.BaseCurrency, 0),
+			expErr:                 true,
+		},
 	} {
 		suite.Run(tc.desc, func() {
 			suite.SetupTest()
@@ -193,6 +216,7 @@ func (suite *TestSuite) TestSwapInAmtGivenOut() {
 			tokenOut, _, _, weightBonus, err := pool.SwapInAmtGivenOut(suite.ctx, suite.app.OracleKeeper, &pool, sdk.Coins{tc.tokenOut}, tc.inTokenDenom, tc.swapFee, suite.app.AccountedPoolKeeper)
 			if tc.expErr {
 				suite.Require().Error(err)
+				suite.Require().EqualError(err, "amount too low")
 			} else {
 				suite.Require().NoError(err)
 				suite.Require().Equal(tokenOut.String(), tc.expTokenIn.String())

diff --git a/x/amm/types/swap_out_amt_given_in_test.go b/x/amm/types/swap_out_amt_given_in_test.go
@@ -569,6 +569,29 @@ func (suite *TestSuite) TestSwapOutAmtGivenIn() {
 			expTokenOut:            sdk.NewInt64Coin("uusdt", 247913188),
 			expErr:                 false,
 		},
+
+		{
+			desc: "tokenOut is zero",
+			poolAssets: []types.PoolAsset{
+				{
+					Token:  sdk.NewInt64Coin(ptypes.BaseCurrency, 500_000_000),
+					Weight: sdk.NewInt(50),
+				},
+				{
+					Token:  sdk.NewInt64Coin("uusdt", 1500_000_000),
+					Weight: sdk.NewInt(50),
+				},
+			},
+			useOracle:              false,
+			externalLiquidityRatio: sdk.NewDec(10),
+			thresholdWeightDiff:    sdk.NewDecWithPrec(20, 2),
+			tokenIn:                sdk.NewInt64Coin(ptypes.BaseCurrency, 0),
+			outTokenDenom:          "uusdt",
+			swapFee:                sdk.NewDecWithPrec(1, 2),
+			expRecoveryBonus:       sdk.ZeroDec(),
+			expTokenOut:            sdk.NewInt64Coin("uusdt", 0),
+			expErr:                 true,
+		},
 	} {
 		suite.Run(tc.desc, func() {
 			suite.SetupTest()
@@ -603,6 +626,7 @@ func (suite *TestSuite) TestSwapOutAmtGivenIn() {
 			tokenOut, _, _, weightBonus, err := pool.SwapOutAmtGivenIn(suite.ctx, suite.app.OracleKeeper, &pool, sdk.Coins{tc.tokenIn}, tc.outTokenDenom, tc.swapFee, suite.app.AccountedPoolKeeper)
 			if tc.expErr {
 				suite.Require().Error(err)
+				suite.Require().EqualError(err, "amount too low")
 			} else {
 				suite.Require().NoError(err)
 				suite.Require().Equal(tokenOut.String(), tc.expTokenOut.String())