Merge pull request #110 from liquity/initial_redemption_rate

feat: Add initial redemption base rate

contracts/src/Interfaces/ITroveManager.sol

@@ -28,10 +28,10 @@ interface ITroveManager is IERC721, ILiquityBase {
     function sortedTroves() external view returns(ISortedTroves);
     function borrowerOperationsAddress() external view returns (address);
 
-    function BOOTSTRAP_PERIOD() external view returns (uint256);
-
     // function BOLD_GAS_COMPENSATION() external view returns (uint256);
 
+    function baseRate() external view returns (uint256);
+
     function getTroveIdsCount() external view returns (uint);
 
     function getTroveFromTroveIdsArray(uint _index) external view returns (uint256);

contracts/src/TroveManager.sol

@@ -46,10 +46,9 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
      */
     uint constant public MINUTE_DECAY_FACTOR = 999037758833783000;
     uint constant public REDEMPTION_FEE_FLOOR = DECIMAL_PRECISION / 1000 * 5; // 0.5%
-    uint constant public MAX_BORROWING_FEE = DECIMAL_PRECISION / 100 * 5; // 5%
+    // To prevent redemptions unless Bold depegs below 0.95 and allow the system to take off
+    uint constant public INITIAL_REDEMPTION_RATE = DECIMAL_PRECISION / 100 * 5; // 5%
 
-    // During bootsrap period redemptions are not allowed
-    uint constant public BOOTSTRAP_PERIOD = 14 days;
 
     /*
     * BETA: 18 digit decimal. Parameter by which to divide the redeemed fraction, in order to calc the new base rate from a redemption.
@@ -258,14 +257,19 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
     event TroveSnapshotsUpdated(uint _L_ETH, uint _L_boldDebt);
     event TroveIndexUpdated(uint256 _troveId, uint _newIndex);
 
-     enum TroveManagerOperation {
+    enum TroveManagerOperation {
         getAndApplyRedistributionGains,
         liquidateInNormalMode,
         liquidateInRecoveryMode,
         redeemCollateral
     }
 
-    constructor() ERC721(NAME, SYMBOL) {}
+    constructor() ERC721(NAME, SYMBOL) {
+        // Update the baseRate state variable
+        // To prevent redemptions unless Bold depegs below 0.95 and allow the system to take off
+        baseRate = INITIAL_REDEMPTION_RATE;
+        emit BaseRateUpdated(INITIAL_REDEMPTION_RATE);
+    }
 
     // --- Dependency setter ---
 
@@ -919,7 +923,6 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
         RedemptionTotals memory totals;
 
         _requireValidMaxFeePercentage(_maxFeePercentage);
-        _requireAfterBootstrapPeriod();
         totals.price = priceFeed.fetchPrice();
         _requireTCRoverMCR(totals.price);
         _requireAmountGreaterThanZero(_boldamount);
@@ -1364,16 +1367,14 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
     }
 
     function getRedemptionRateWithDecay() public view override returns (uint) {
-        return 0;
-        // return _calcRedemptionRate(_calcDecayedBaseRate());
+        return _calcRedemptionRate(_calcDecayedBaseRate());
     }
 
-    function _calcRedemptionRate(uint /* _baseRate */) internal pure returns (uint) {
-        return 0;
-        // return LiquityMath._min(
-        //     REDEMPTION_FEE_FLOOR + _baseRate,
-        //     DECIMAL_PRECISION // cap at a maximum of 100%
-        // );
+    function _calcRedemptionRate(uint _baseRate) internal pure returns (uint) {
+        return LiquityMath._min(
+            REDEMPTION_FEE_FLOOR + _baseRate,
+            DECIMAL_PRECISION // cap at a maximum of 100%
+        );
     }
 
     function _getRedemptionFee(uint _ETHDrawn) internal view returns (uint) {
@@ -1384,11 +1385,10 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
         return _calcRedemptionFee(getRedemptionRateWithDecay(), _ETHDrawn);
     }
 
-    function _calcRedemptionFee(uint /* _redemptionRate */, uint /* _ETHDrawn */) internal pure returns (uint) {
-        return 0;
-        // uint redemptionFee = _redemptionRate * _ETHDrawn / DECIMAL_PRECISION;
-        // require(redemptionFee < _ETHDrawn, "TroveManager: Fee would eat up all returned collateral");
-        // return redemptionFee;
+    function _calcRedemptionFee(uint _redemptionRate, uint _ETHDrawn) internal pure returns (uint) {
+        uint redemptionFee = _redemptionRate * _ETHDrawn / DECIMAL_PRECISION;
+        require(redemptionFee < _ETHDrawn, "TroveManager: Fee would eat up all returned collateral");
+        return redemptionFee;
     }
 
     // --- Internal fee functions ---
@@ -1471,11 +1471,6 @@ contract TroveManager is ERC721, LiquityBase, Ownable, CheckContract, ITroveMana
         require(_getTCR(_price) >= MCR, "TroveManager: Cannot redeem when TCR < MCR");
     }
 
-    function _requireAfterBootstrapPeriod() internal view {
-        uint systemDeploymentTime = boldToken.deploymentStartTime();
-        require(block.timestamp >= systemDeploymentTime + BOOTSTRAP_PERIOD, "TroveManager: Redemptions are not allowed during bootstrap phase");
-    }
-
     function _requireValidMaxFeePercentage(uint _maxFeePercentage) internal pure {
         require(_maxFeePercentage >= REDEMPTION_FEE_FLOOR && _maxFeePercentage <= DECIMAL_PRECISION,
             "Max fee percentage must be between 0.5% and 100%");

contracts/src/test/basicOps.t.sol

@@ -46,11 +46,11 @@ contract BasicOps is DevTestSetup {
 
         uint256 trovesCount = troveManager.getTroveIdsCount();
         assertEq(trovesCount, 2);
-       
+
         vm.startPrank(B);
         borrowerOperations.closeTrove(B_Id);
         vm.stopPrank();
-    
+
         // Check Troves count reduced by 1
         trovesCount = troveManager.getTroveIdsCount();
         assertEq(trovesCount, 1);
@@ -66,7 +66,7 @@ contract BasicOps is DevTestSetup {
         assertGt(debt_1, 0);
         uint256 coll_1 = troveManager.getTroveColl(A_Id);
         assertGt(coll_1, 0);
- 
+
         // Adjust trove
         borrowerOperations.adjustTrove(A_Id, 1e18, 1e18, true, 500e18,  true);
 
@@ -94,8 +94,6 @@ contract BasicOps is DevTestSetup {
 
         // B is now first in line to get redeemed, as they both have the same interest rate,
         // but B's Trove is younger.
-
-        vm.warp(block.timestamp + troveManager.BOOTSTRAP_PERIOD() + 1);
 
         uint256 redemptionAmount = 1000e18;  // 1k BOLD
 
@@ -106,7 +104,7 @@ contract BasicOps is DevTestSetup {
             10,
             1e18
         );
-       
+
         // Check B's coll and debt reduced
         uint256 debt_2 = troveManager.getTroveDebt(B_Id);
         assertLt(debt_2, debt_1);

contracts/src/test/troveManager.t.sol

@@ -20,8 +20,6 @@ contract TroveManagerTest is DevTestSetup {
         uint256 collB1 = troveManager.getTroveColl(BTroveId);
         assertGt(collB1, 0);
 
-        // fast-forward until redemptions are enabled
-        vm.warp(block.timestamp + troveManager.BOOTSTRAP_PERIOD() + 1);
         // Reduce ETH price so A’s ICR goes below 100%
         uint256 newPrice = 1000e18;
         priceFeed.setPrice(newPrice);
@@ -51,4 +49,29 @@ contract TroveManagerTest is DevTestSetup {
         uint256 collB2 = troveManager.getTroveColl(BTroveId);
         assertLt(collB2, collB1, "B coll mismatch");
     }
+
+    function testInitialRedemptionBaseRate() public {
+        assertEq(troveManager.baseRate(), 5e16);
+    }
+
+    function testRedemptionBaseRateAfter2Weeks() public {
+        assertEq(troveManager.baseRate(), 5e16);
+
+        // Two weeks go by
+        vm.warp(block.timestamp + 14 days);
+
+        priceFeed.setPrice(2000e18);
+        openTroveNoHints100pctMaxFee(A, 200 ether, 200000e18, 1e17);
+        // A redeems 0.01 BOLD, base rate goes down to almost zero (it’s updated on redemption)
+        vm.startPrank(A);
+        troveManager.redeemCollateral(
+            1e16,
+            10,
+            1e18
+        );
+        vm.stopPrank();
+
+        console.log(troveManager.baseRate(), "baseRate");
+        assertLt(troveManager.baseRate(), 3e10); // Goes down below 3e-8, i.e., below 0.000003%
+    }
 }

contracts/test/BorrowerOperationsTest.js

@@ -3551,8 +3551,8 @@ contract("BorrowerOperations", async (accounts) => {
 
       const baseRateBefore = await troveManager.baseRate();
 
-      // Artificially make baseRate 5%
-      await troveManager.setBaseRate(dec(5, 16));
+      // Artificially make baseRate 6% (higher than the intital 5%)
+      await troveManager.setBaseRate(dec(6, 16));
       await troveManager.setLastFeeOpTimeToNow();
 
       assert.isTrue((await troveManager.baseRate()).gt(baseRateBefore));