From d0239e90e12ba4bec3b1607bc2751e0881593ee2 Mon Sep 17 00:00:00 2001
From: alpo <62043214+AlpinYukseloglu@users.noreply.github.com>
Date: Tue, 14 Jun 2022 21:23:36 -0500
Subject: [PATCH] Tests: Edge case tests for CalcJoinPoolShares (#1776)

* edge case tests for CalcJoinPoolShares

* add test comments

* move tests to increase coverage and add further comments

* remove expectLiq from new tests

* fix conflicts

Co-authored-by: Roman <roman@osmosis.team>
---
 .../pool-models/balancer/amm_joinpool_test.go | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)

diff --git a/x/gamm/pool-models/balancer/amm_joinpool_test.go b/x/gamm/pool-models/balancer/amm_joinpool_test.go
index ef4adefc9b6..8419de7528d 100644
--- a/x/gamm/pool-models/balancer/amm_joinpool_test.go
+++ b/x/gamm/pool-models/balancer/amm_joinpool_test.go
@@ -379,6 +379,46 @@ var calcSingleAssetJoinTestCases = []calcJoinSharesTestCase{
 		expectShares: sdk.ZeroInt(),
 		expErr:       sdkerrors.Wrapf(types.ErrDenomNotFoundInPool, fmt.Sprintf(balancer.ErrMsgFormatNoPoolAssetFound, doesNotExistDenom)),
 	},
+	{
+		// Pool liquidity is changed by 1e-12 / 2
+		// P_issued = 1e20 * 1e-12 / 2 = 1e8 / 2 = 50_000_000
+		name:    "minimum input single asset equal liquidity",
+		swapFee: sdk.MustNewDecFromStr("0"),
+		poolAssets: []balancer.PoolAsset{
+			{
+				Token:  sdk.NewInt64Coin("uosmo", 1_000_000_000_000),
+				Weight: sdk.NewInt(100),
+			},
+			{
+				Token:  sdk.NewInt64Coin("uatom", 1_000_000_000_000),
+				Weight: sdk.NewInt(100),
+			},
+		},
+		tokensIn: sdk.NewCoins(
+			sdk.NewInt64Coin("uosmo", 1),
+		),
+		expectShares: sdk.NewInt(50_000_000),
+	},
+	{
+		// P_issued should be 1/10th that of the previous test
+		// p_issued = 50_000_000 / 10 = 5_000_000
+		name:    "minimum input single asset imbalanced liquidity",
+		swapFee: sdk.MustNewDecFromStr("0"),
+		poolAssets: []balancer.PoolAsset{
+			{
+				Token:  sdk.NewInt64Coin("uosmo", 10_000_000_000_000),
+				Weight: sdk.NewInt(100),
+			},
+			{
+				Token:  sdk.NewInt64Coin("uatom", 1_000_000_000_000),
+				Weight: sdk.NewInt(100),
+			},
+		},
+		tokensIn: sdk.NewCoins(
+			sdk.NewInt64Coin("uosmo", 1),
+		),
+		expectShares: sdk.NewInt(5_000_000),
+	},
 }
 
 func (suite *KeeperTestSuite) TestCalcJoinPoolShares() {
@@ -501,6 +541,49 @@ func (suite *KeeperTestSuite) TestCalcJoinPoolShares() {
 			),
 			expectShares: sdk.NewInt(1250000000000 + 609374990000),
 		},
+		{
+			// This test doubles the liquidity in a fresh pool, so it should generate the base number of LP shares for pool creation as new shares
+			// This is set to 1e20 (or 100 * 10^18) for Osmosis, so we should expect:
+			// P_issued = 1e20
+			name:    "minimum input with two assets and minimum liquidity",
+			swapFee: sdk.MustNewDecFromStr("0"),
+			poolAssets: []balancer.PoolAsset{
+				{
+					Token:  sdk.NewInt64Coin("uosmo", 1),
+					Weight: sdk.NewInt(100),
+				},
+				{
+					Token:  sdk.NewInt64Coin("uatom", 1),
+					Weight: sdk.NewInt(100),
+				},
+			},
+			tokensIn: sdk.NewCoins(
+				sdk.NewInt64Coin("uosmo", 1),
+				sdk.NewInt64Coin("uatom", 1),
+			),
+			expectShares: sdk.NewInt(1e18).Mul(sdk.NewInt(100)),
+		},
+		{
+			// Pool liquidity is changed by 1e-12
+			// P_issued = 1e20 * 1e-12 = 1e8
+			name:    "minimum input two assets equal liquidity",
+			swapFee: sdk.MustNewDecFromStr("0"),
+			poolAssets: []balancer.PoolAsset{
+				{
+					Token:  sdk.NewInt64Coin("uosmo", 1_000_000_000_000),
+					Weight: sdk.NewInt(100),
+				},
+				{
+					Token:  sdk.NewInt64Coin("uatom", 1_000_000_000_000),
+					Weight: sdk.NewInt(100),
+				},
+			},
+			tokensIn: sdk.NewCoins(
+				sdk.NewInt64Coin("uosmo", 1),
+				sdk.NewInt64Coin("uatom", 1),
+			),
+			expectShares: sdk.NewInt(100_000_000),
+		},
 	}
 	testCases = append(testCases, calcSingleAssetJoinTestCases...)