Add invariant_Tranche_K

Author: bin-57blocks

test/invariant/BaseInvariants.sol

@@ -5,7 +5,7 @@ import {BaseTest} from "./BaseTest.sol";
 import {EpochManager} from "contracts/liquidity/EpochManager.sol";
 import {PayPeriodDuration} from "contracts/common/SharedDefs.sol";
 import {PoolSettings, LPConfig, FrontLoadingFeesStructure, FeeStructure, FirstLossCoverConfig} from "contracts/common/PoolConfig.sol";
-import {BORROWER_LOSS_COVER_INDEX, ADMIN_LOSS_COVER_INDEX, SENIOR_TRANCHE, JUNIOR_TRANCHE} from "contracts/common/SharedDefs.sol";
+import {BORROWER_LOSS_COVER_INDEX, ADMIN_LOSS_COVER_INDEX, SENIOR_TRANCHE, JUNIOR_TRANCHE, HUNDRED_PERCENT_IN_BPS} from "contracts/common/SharedDefs.sol";
 import {CreditRecord, CreditConfig, CreditState, DueDetail} from "contracts/credit/CreditStructs.sol";
 
 import "forge-std/console.sol";
@@ -398,6 +398,14 @@ contract BaseInvariants is BaseTest {
         );
     }
 
+    function _assert_Tranche_K() internal {
+        assertGe(
+            juniorTranche.totalAssets() * poolConfig.getLPConfig().maxSeniorJuniorRatio,
+            seniorTranche.totalAssets(),
+            "Tranche Invariant K"
+        );
+    }
+
     function _assert_EpochManager_A() internal {
         EpochManager.CurrentEpoch memory epoch = epochManager.currentEpoch();
         assertGt(epoch.endTime, block.timestamp, "EpochManager Invariant A");

test/invariant/LiquidityInvariants.t.sol

@@ -100,6 +100,10 @@ contract LiquidityInvariants is BaseInvariants {
         _assert_Tranche_J();
     }
 
+    function invariant_Tranche_K() public {
+        _assert_Tranche_K();
+    }
+
     function invariant_EpochManager_A() public {
         _assert_EpochManager_A();
     }
@@ -147,6 +151,7 @@ contract LiquidityInvariants is BaseInvariants {
         _assert_Tranche_G();
         _assert_Tranche_H_I();
         _assert_Tranche_J();
+        _assert_Tranche_K();
     }
 
     function test_EpochManager_invariants() public {