From 2efcd4c0d3a6691fbba431a7a25d50fcf7418260 Mon Sep 17 00:00:00 2001
From: tim <timolsoncrypto@gmail.com>
Date: Tue, 25 Nov 2025 16:06:15 -0400
Subject: [PATCH] improved price tests

---
 test/PartyPool.t.sol | 51 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/test/PartyPool.t.sol b/test/PartyPool.t.sol
index 5b26d26..1a09eab 100644
--- a/test/PartyPool.t.sol
+++ b/test/PartyPool.t.sol
@@ -2,6 +2,7 @@
 /* solhint-disable */
 pragma solidity ^0.8.30;
 
+import "forge-std/console2.sol";
 import {ABDKMath64x64} from "../lib/abdk-libraries-solidity/ABDKMath64x64.sol";
 import {CommonBase} from "../lib/forge-std/src/Base.sol";
 import {StdAssertions} from "../lib/forge-std/src/StdAssertions.sol";
@@ -1145,5 +1146,55 @@ contract PartyPoolTest is Test {
         assertEq(uint256(uint128(price)), uint256(uint128(expected)), "Price token1/token0 should be 3.0000000");
     }
 
+    /// @notice Verify that PartyInfo.price() agrees (within tolerance) with the swapAmounts() quote
+    /// for a very small (de-minimis) exact-input swap from token1 -> token0.
+    function testPriceMatchesSwapForSmallInput() public {
+        // Build tokens array (reuse test tokens)
+        IERC20[] memory tokens = new IERC20[](3);
+        tokens[0] = IERC20(address(token0));
+        tokens[1] = IERC20(address(token1));
+        tokens[2] = IERC20(address(token2));
+
+        uint256 feePpm = 0;
+        // Use a large kappa to prevent slippage
+        int128 kappa = ABDKMath64x64.fromUInt(100);
+
+        // Prepare explicit per-token initial deposits so token0 starts at 3x token1
+        uint256[] memory deposits = new uint256[](3);
+        deposits[0] = INIT_BAL * 3; // token0 = 3 * INIT_BAL
+        deposits[1] = INIT_BAL;     // token1 = INIT_BAL
+        deposits[2] = INIT_BAL;     // token2 = INIT_BAL
+
+        // Deploy a fresh pool with the specified deposits
+        (IPartyPool poolCustom, ) = Deploy.newPartyPoolWithDeposits("LP3X_SWAP", "LP3X_SWAP", tokens, kappa, feePpm, feePpm, false, deposits, 0);
+
+        // Query the info viewer for the marginal price token1 (base) denominated in token0 (quote)
+        int128 infoPrice = info.price(poolCustom, 1, 0);
+
+        // Choose a small-but-sufficient input amount in external units to avoid underflow/rounding issues
+        uint256 inputAmount = INIT_BAL/100;
+
+        // Query the swapAmounts view to get grossIn (includes fee), amountOut, and fee
+        (uint256 grossIn, uint256 amountOut, uint256 inFee) = poolCustom.swapAmounts(1, 0, inputAmount, 0);
+
+        // Net input consumed by kernel excludes the fee
+        uint256 netIn = grossIn > inFee ? grossIn - inFee : 0;
+        require(netIn > 0, "net input must be positive for price comparison");
+
+        // Compute swap-implied price as Q64.64 (quote per base) = amountOut / netIn
+        int128 swapPrice = ABDKMath64x64.divu(amountOut, netIn);
+        console2.log('info price', infoPrice);
+        console2.log('swap price', swapPrice);
+
+        // Absolute difference between info.price and swap-implied price
+        int128 slippage = ABDKMath64x64.fromUInt(1) - swapPrice.div(infoPrice);
+        console2.log('slippage', slippage);
+
+        // Tolerance ~ 4e-5 in Q64.64
+        int128 tol = ABDKMath64x64.divu(4, 100_000);
+
+        assertTrue(slippage <= tol, "price from info and swapAmounts should be close");
+    }
+
 }
 /* solhint-enable */