[Fix] maker-minor funding allocation during socialization (#64)

* add basic all positions tests

* position delta tests

* price delta tests

* add liquidation test

* partial socialization test

* add closed test

* shortfall test

* long liquidation tests

* fix test conflict

* fix rebase

package.json

@@ -44,6 +44,7 @@
     "hardhat-dependency-compiler": "1.1.3",
     "hardhat-deploy": "0.11.31",
     "hardhat-gas-reporter": "1.0.9",
+    "hardhat-tracer": "2.5.1",
     "husky": ">=6",
     "lerna": "^4.0.0",
     "lint-staged": ">=10",

packages/common/hardhat.default.config.ts

@@ -8,7 +8,9 @@ import '@nomicfoundation/hardhat-toolbox'
 import 'hardhat-contract-sizer'
 import 'hardhat-deploy'
 import 'hardhat-dependency-compiler'
+import 'hardhat-tracer'
 import 'solidity-coverage'
+
 import { getChainId, isArbitrum, isBase, isOptimism, SupportedChain } from './testutil/network'
 
 import { utils } from 'ethers'

packages/perennial/contracts/types/Position.sol

@@ -209,6 +209,16 @@ library PositionLib {
         return _skew(self, riskParameter.virtualTaker);
     }
 
+    /// @notice Returns the skew of the position taking into account position socialization
+    /// @dev Used to calculate the portion of the position that is covered by the maker
+    /// @param self The position object to check
+    /// @return The socialized skew of the position
+    function socializedSkew(Position memory self) internal pure returns (UFixed6) {
+        return takerSocialized(self).isZero() ?
+            UFixed6Lib.ZERO :
+            takerSocialized(self).sub(minor(self)).div(takerSocialized(self));
+    }
+
     /// @notice Helper function to return the skew of the position with an optional virtual taker
     /// @param self The position object to check
     /// @param virtualTaker The virtual taker to use in the calculation

packages/perennial/contracts/types/Version.sol

@@ -115,7 +115,7 @@ library VersionLib {
         );
 
         // accumulate interest
-        (values.interestMaker,values.interestLong, values.interestShort, values.interestFee) =
+        (values.interestMaker, values.interestLong, values.interestShort, values.interestFee) =
             _accumulateInterest(self, fromPosition, fromOracleVersion, toOracleVersion, marketParameter, riskParameter);
 
         // accumulate P&L
@@ -207,11 +207,11 @@ library VersionLib {
 
         // Redirect net portion of minor's side to maker
         if (fromPosition.long.gt(fromPosition.short)) {
-            fundingValues.fundingMaker = fundingValues.fundingShort.mul(Fixed6Lib.from(fromPosition.skew().abs()));
+            fundingValues.fundingMaker = fundingValues.fundingShort.mul(Fixed6Lib.from(fromPosition.socializedSkew()));
             fundingValues.fundingShort = fundingValues.fundingShort.sub(fundingValues.fundingMaker);
         }
         if (fromPosition.short.gt(fromPosition.long)) {
-            fundingValues.fundingMaker = fundingValues.fundingLong.mul(Fixed6Lib.from(fromPosition.skew().abs()));
+            fundingValues.fundingMaker = fundingValues.fundingLong.mul(Fixed6Lib.from(fromPosition.socializedSkew()));
             fundingValues.fundingLong = fundingValues.fundingLong.sub(fundingValues.fundingMaker);
         }