Fix lp logic, add test cases (#1708)

Co-authored-by: Dev Ojha <[email protected]>
osmosis-labs · Jun 8, 2022 · 94a3878 · 94a3878
1 parent 840466a
commit 94a3878
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Showing 2 changed files with 70 additions and 1 deletion.
diff --git a/x/gamm/pool-models/internal/cfmm_common/lp.go b/x/gamm/pool-models/internal/cfmm_common/lp.go
@@ -87,7 +87,7 @@ func MaximalExactRatioJoin(p types.PoolI, ctx sdk.Context, tokensIn sdk.Coins) (
 				continue
 			}
 
-			usedAmount := minShareRatio.MulInt(coin.Amount).Ceil().TruncateInt()
+			usedAmount := minShareRatio.MulInt(poolLiquidity.AmountOfNoDenomValidation(coin.Denom)).Ceil().TruncateInt()
 			newAmt := coin.Amount.Sub(usedAmount)
 			// if newAmt is non-zero, add to RemCoins. (It could be zero due to rounding)
 			if !newAmt.IsZero() {

diff --git a/x/gamm/pool-models/internal/cfmm_common/lp_test.go b/x/gamm/pool-models/internal/cfmm_common/lp_test.go
@@ -136,3 +136,72 @@ func TestCalcExitPool(t *testing.T) {
 		}
 	}
 }
+
+func TestMaximalExactRatioJoin(t *testing.T) {
+	emptyContext := sdk.Context{}
+
+	balancerPoolAsset := []balancer.PoolAsset{
+		{Token: sdk.NewInt64Coin("foo", 100), Weight: sdk.NewIntFromUint64(5)},
+		{Token: sdk.NewInt64Coin("bar", 100), Weight: sdk.NewIntFromUint64(5)},
+	}
+
+	tests := []struct {
+		name        string
+		pool        func() gammtypes.PoolI
+		tokensIn    sdk.Coins
+		expNumShare sdk.Int
+		expRemCoin  sdk.Coins
+	}{
+		{
+			name: "two asset pool, same tokenIn ratio",
+			pool: func() gammtypes.PoolI {
+				balancerPool, err := balancer.NewBalancerPool(
+					1,
+					balancer.PoolParams{SwapFee: sdk.ZeroDec(), ExitFee: sdk.ZeroDec()},
+					balancerPoolAsset,
+					"",
+					time.Now(),
+				)
+				require.NoError(t, err)
+				return &balancerPool
+			},
+			tokensIn:    sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(10)), sdk.NewCoin("bar", sdk.NewInt(10))),
+			expNumShare: sdk.NewIntFromUint64(10000000000000000000),
+			expRemCoin:  sdk.Coins{},
+		},
+		{
+			name: "two asset pool, different tokenIn ratio with pool",
+			pool: func() gammtypes.PoolI {
+				balancerPool, err := balancer.NewBalancerPool(
+					1,
+					balancer.PoolParams{SwapFee: sdk.ZeroDec(), ExitFee: sdk.ZeroDec()},
+					balancerPoolAsset,
+					"",
+					time.Now(),
+				)
+				require.NoError(t, err)
+				return &balancerPool
+			},
+			tokensIn:    sdk.NewCoins(sdk.NewCoin("foo", sdk.NewInt(10)), sdk.NewCoin("bar", sdk.NewInt(11))),
+			expNumShare: sdk.NewIntFromUint64(10000000000000000000),
+			expRemCoin:  sdk.NewCoins(sdk.NewCoin("bar", sdk.NewIntFromUint64(1))),
+		},
+	}
+
+	for _, test := range tests {
+		balancerPool, err := balancer.NewBalancerPool(
+			1,
+			balancer.PoolParams{SwapFee: sdk.ZeroDec(), ExitFee: sdk.ZeroDec()},
+			balancerPoolAsset,
+			"",
+			time.Now(),
+		)
+		require.NoError(t, err)
+
+		numShare, remCoins, err := cfmm_common.MaximalExactRatioJoin(&balancerPool, emptyContext, test.tokensIn)
+
+		require.NoError(t, err)
+		require.Equal(t, test.expNumShare, numShare)
+		require.Equal(t, test.expRemCoin, remCoins)
+	}
+}