[VPD-675]: Repay Logic Improvement

simulations/vip-610/bscmainnet.ts

@@ -0,0 +1,348 @@
+import { TransactionResponse } from "@ethersproject/providers";
+import { expect } from "chai";
+import { BigNumber, Contract } from "ethers";
+import { parseUnits } from "ethers/lib/utils";
+import { ethers } from "hardhat";
+import { NETWORK_ADDRESSES } from "src/networkAddresses";
+import {
+  expectEvents,
+  initMainnetUser,
+  setMaxStalePeriodInBinanceOracle,
+  setMaxStalePeriodInChainlinkOracle,
+  setRedstonePrice,
+} from "src/utils";
+import { forking, testVip } from "src/vip-framework";
+import { checkCorePoolComptroller } from "src/vip-framework/checks/checkCorePoolComptroller";
+
+import vip596, { CORE_MARKETS, NEW_VBEP20_DELEGATE_IMPL } from "../../vips/vip-610/bscmainnet";
+import COMPTROLLER_ABI from "./abi/Comptroller.json";
+import VBEP20_DELEGATOR_ABI from "./abi/VBep20Delegator.json";
+import VTOKEN_ABI from "./abi/VToken.json";
+import ERC20_ABI from "./abi/erc20.json";
+
+const { bscmainnet } = NETWORK_ADDRESSES;
+
+const COMPTROLLER_LENS = "0x732138e18fa6f8f8E456ad829DB429A450a79758";
+const GENERIC_ETH_ACCOUNT = "0xF77055DBFAfdD56578Ace54E62e749d12802ce36";
+
+// vUSDT market for core operations testing
+const VUSDT_ADDRESS = "0xfD5840Cd36d94D7229439859C0112a4185BC0255";
+const USDT_ADDRESS = "0x55d398326f99059fF775485246999027B3197955";
+const USDT_WHALE = "0xF977814e90dA44bFA03b6295A0616a897441aceC";
+
+// vUSDC market as collateral
+const VUSDC_ADDRESS = "0xecA88125a5ADbe82614ffC12D0DB554E2e2867C8";
+const USDC_ADDRESS = "0x8AC76a51cc950d9822D68b83fE1Ad97B32Cd580d";
+const USDC_WHALE = "0xF977814e90dA44bFA03b6295A0616a897441aceC";
+
+const UNITROLLER = "0xfD36E2c2a6789Db23113685031d7F16329158384";
+
+const BLOCK_NUMBER = 83622252;
+
+forking(BLOCK_NUMBER, async () => {
+  let comptroller: Contract;
+  let vUSDT: Contract;
+  let usdt: Contract;
+  let vUSDC: Contract;
+  let usdc: Contract;
+
+  before(async () => {
+    comptroller = new ethers.Contract(UNITROLLER, COMPTROLLER_ABI, ethers.provider);
+    vUSDT = new ethers.Contract(VUSDT_ADDRESS, VTOKEN_ABI, ethers.provider);
+    usdt = new ethers.Contract(USDT_ADDRESS, ERC20_ABI, ethers.provider);
+    vUSDC = new ethers.Contract(VUSDC_ADDRESS, VTOKEN_ABI, ethers.provider);
+    usdc = new ethers.Contract(USDC_ADDRESS, ERC20_ABI, ethers.provider);
+
+    for (const market of CORE_MARKETS) {
+      await setMaxStalePeriodInChainlinkOracle(
+        bscmainnet.CHAINLINK_ORACLE,
+        market.underlying,
+        ethers.constants.AddressZero,
+        bscmainnet.NORMAL_TIMELOCK,
+        315360000,
+      );
+
+      await setMaxStalePeriodInChainlinkOracle(
+        bscmainnet.REDSTONE_ORACLE,
+        market.underlying,
+        ethers.constants.AddressZero,
+        bscmainnet.NORMAL_TIMELOCK,
+        315360000,
+      );
+      await setMaxStalePeriodInBinanceOracle(bscmainnet.BINANCE_ORACLE, market.symbol.slice(1), 315360000);
+    }
+
+    const xSolvBTC = "0x1346b618dC92810EC74163e4c27004c921D446a5";
+    const xSolvBTC_RedStone_Feed = "0x24c8964338Deb5204B096039147B8e8C3AEa42Cc";
+    await setRedstonePrice(bscmainnet.REDSTONE_ORACLE, xSolvBTC, xSolvBTC_RedStone_Feed, bscmainnet.NORMAL_TIMELOCK);
+
+    const THE = "0xF4C8E32EaDEC4BFe97E0F595AdD0f4450a863a11";
+    const THE_REDSTONE_FEED = "0xFB1267A29C0aa19daae4a483ea895862A69e4AA5";
+    await setRedstonePrice(bscmainnet.REDSTONE_ORACLE, THE, THE_REDSTONE_FEED, bscmainnet.NORMAL_TIMELOCK);
+
+    const TRX = "0xCE7de646e7208a4Ef112cb6ed5038FA6cC6b12e3";
+    const TRX_REDSTONE_FEED = "0xa17362dd9AD6d0aF646D7C8f8578fddbfc90B916";
+    await setRedstonePrice(bscmainnet.REDSTONE_ORACLE, TRX, TRX_REDSTONE_FEED, bscmainnet.NORMAL_TIMELOCK, 3153600000, {
+      tokenDecimals: 6,
+    });
+  });
+
+  describe("Pre-VIP state", async () => {
+    it("markets should have old implementation", async () => {
+      for (const market of CORE_MARKETS) {
+        const marketContract = await ethers.getContractAt(VBEP20_DELEGATOR_ABI, market.address);
+        const currentImpl = await marketContract.implementation();
+        expect(currentImpl).to.not.equal(NEW_VBEP20_DELEGATE_IMPL);
+      }
+    });
+  });
+
+  testVip("VIP-596 Mainnet", await vip596(), {
+    callbackAfterExecution: async (txResponse: TransactionResponse) => {
+      const totalMarkets = CORE_MARKETS.length;
+      await expectEvents(txResponse, [VBEP20_DELEGATOR_ABI], ["NewImplementation"], [totalMarkets]);
+    },
+  });
+
+  describe("Post-VIP state", async () => {
+    it("markets should have new implementation", async () => {
+      for (const market of CORE_MARKETS) {
+        const marketContract = await ethers.getContractAt(VBEP20_DELEGATOR_ABI, market.address);
+        expect(await marketContract.implementation()).to.equal(NEW_VBEP20_DELEGATE_IMPL);
+      }
+    });
+  });
+
+  describe("Core operations: mint, borrow, repay, redeem", async () => {
+    let user: any;
+    let userAddress: string;
+
+    before(async () => {
+      const usdcWhale = await initMainnetUser(USDC_WHALE, ethers.utils.parseEther("1"));
+      const usdtWhale = await initMainnetUser(USDT_WHALE, ethers.utils.parseEther("1"));
+
+      const [signer] = await ethers.getSigners();
+      user = signer;
+      userAddress = await user.getAddress();
+
+      await usdc.connect(usdcWhale).transfer(userAddress, parseUnits("10000", 18));
+      await usdt.connect(usdtWhale).transfer(userAddress, parseUnits("10000", 18));
+    });
+
+    it("should mint (supply) USDC to vUSDC", async () => {
+      const mintAmount = parseUnits("5000", 18);
+      await usdc.connect(user).approve(VUSDC_ADDRESS, mintAmount);
+      await vUSDC.connect(user).mint(mintAmount);
+
+      const vUSDCBalance = await vUSDC.balanceOf(userAddress);
+      expect(vUSDCBalance).to.be.gt(0);
+    });
+
+    it("should borrow USDT against USDC collateral", async () => {
+      await comptroller.connect(user).enterMarkets([VUSDC_ADDRESS]);
+
+      const borrowAmount = parseUnits("1000", 18);
+      const usdtBefore = await usdt.balanceOf(userAddress);
+      await vUSDT.connect(user).borrow(borrowAmount);
+      const usdtAfter = await usdt.balanceOf(userAddress);
+
+      expect(usdtAfter.sub(usdtBefore)).to.equal(borrowAmount);
+    });
+
+    it("should repay partial USDT borrow", async () => {
+      const borrowBefore = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowBefore).to.be.gt(0);
+
+      const repayAmount = parseUnits("500", 18);
+      await usdt.connect(user).approve(VUSDT_ADDRESS, repayAmount);
+      await vUSDT.connect(user).repayBorrow(repayAmount);
+
+      const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowAfter).to.be.lt(borrowBefore);
+    });
+
+    it("should fully repay using type(uint256).max", async () => {
+      const borrowBefore = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowBefore).to.be.gt(0);
+
+      await usdt.connect(user).approve(VUSDT_ADDRESS, ethers.constants.MaxUint256);
+      await vUSDT.connect(user).repayBorrow(ethers.constants.MaxUint256);
+
+      const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowAfter).to.equal(0);
+    });
+
+    it("should redeem USDC from vUSDC", async () => {
+      const usdcBefore = await usdc.balanceOf(userAddress);
+      const redeemAmount = parseUnits("1000", 18);
+      await vUSDC.connect(user).redeemUnderlying(redeemAmount);
+      const usdcAfter = await usdc.balanceOf(userAddress);
+
+      expect(usdcAfter.sub(usdcBefore)).to.equal(redeemAmount);
+    });
+  });
+
+  describe("Repay logic change: caps repayment to actual borrow balance", async () => {
+    let user: any;
+    let userAddress: string;
+
+    before(async () => {
+      const usdcWhale = await initMainnetUser(USDC_WHALE, ethers.utils.parseEther("1"));
+      const usdtWhale = await initMainnetUser(USDT_WHALE, ethers.utils.parseEther("1"));
+
+      const signers = await ethers.getSigners();
+      user = signers[1];
+      userAddress = await user.getAddress();
+
+      await usdc.connect(usdcWhale).transfer(userAddress, parseUnits("10000", 18));
+      await usdt.connect(usdtWhale).transfer(userAddress, parseUnits("10000", 18));
+
+      // Supply collateral and borrow
+      await usdc.connect(user).approve(VUSDC_ADDRESS, parseUnits("5000", 18));
+      await vUSDC.connect(user).mint(parseUnits("5000", 18));
+      await comptroller.connect(user).enterMarkets([VUSDC_ADDRESS]);
+      await vUSDT.connect(user).borrow(parseUnits("100", 18));
+    });
+
+    it("should cap repayment when amount exceeds borrow balance", async () => {
+      const borrowBalance: BigNumber = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowBalance).to.be.gt(0);
+
+      // Approve and repay 2x the borrow balance — should be capped to actual debt
+      const excessAmount = borrowBalance.mul(2);
+      const usdtBefore = await usdt.balanceOf(userAddress);
+
+      await usdt.connect(user).approve(VUSDT_ADDRESS, excessAmount);
+      await vUSDT.connect(user).repayBorrow(excessAmount);
+
+      const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(userAddress);
+      expect(borrowAfter).to.equal(0);
+
+      // Verify only the actual borrow amount was taken, not the excess
+      const usdtAfter = await usdt.balanceOf(userAddress);
+      const actualRepaid = usdtBefore.sub(usdtAfter);
+
+      // actualRepaid should be close to borrowBalance (within interest accrual tolerance)
+      const tolerance = borrowBalance.mul(1).div(100); // 1% tolerance for interest
+      expect(actualRepaid).to.be.closeTo(borrowBalance, tolerance);
+    });
+  });
+
+  describe("repayBorrowBehalf: third-party repay (SwapRouter path)", async () => {
+    let borrower: any;
+    let borrowerAddress: string;
+    let repayer: any;
+    let repayerAddress: string;
+
+    before(async () => {
+      const usdcWhale = await initMainnetUser(USDC_WHALE, ethers.utils.parseEther("1"));
+      const usdtWhale = await initMainnetUser(USDT_WHALE, ethers.utils.parseEther("1"));
+
+      const signers = await ethers.getSigners();
+      borrower = signers[4];
+      borrowerAddress = await borrower.getAddress();
+      repayer = signers[5];
+      repayerAddress = await repayer.getAddress();
+
+      await usdc.connect(usdcWhale).transfer(borrowerAddress, parseUnits("5000", 18));
+      await usdt.connect(usdtWhale).transfer(repayerAddress, parseUnits("10000", 18));
+
+      // Borrower: supply USDC and borrow USDT
+      await usdc.connect(borrower).approve(VUSDC_ADDRESS, parseUnits("5000", 18));
+      await vUSDC.connect(borrower).mint(parseUnits("5000", 18));
+      await comptroller.connect(borrower).enterMarkets([VUSDC_ADDRESS]);
+      await vUSDT.connect(borrower).borrow(parseUnits("100", 18));
+    });
+
+    it("repayBorrowBehalf should work with exact amount", async () => {
+      const borrowBalance: BigNumber = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+      expect(borrowBalance).to.be.gt(0);
+
+      const repayAmount = parseUnits("50", 18);
+      await usdt.connect(repayer).approve(VUSDT_ADDRESS, repayAmount);
+      await vUSDT.connect(repayer).repayBorrowBehalf(borrowerAddress, repayAmount);
+
+      const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+      expect(borrowAfter).to.be.lt(borrowBalance);
+    });
+
+    it("repayBorrowBehalf should cap when amount exceeds borrow balance", async () => {
+      const borrowBalance: BigNumber = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+      expect(borrowBalance).to.be.gt(0);
+
+      // Repayer sends 2x the borrow balance — should be capped
+      const excessAmount = borrowBalance.mul(2);
+      const usdtBefore = await usdt.balanceOf(repayerAddress);
+
+      await usdt.connect(repayer).approve(VUSDT_ADDRESS, excessAmount);
+      await vUSDT.connect(repayer).repayBorrowBehalf(borrowerAddress, excessAmount);
+
+      const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+      expect(borrowAfter).to.equal(0);
+
+      // Verify only the actual borrow amount was taken from repayer
+      const usdtAfter = await usdt.balanceOf(repayerAddress);
+      const actualRepaid = usdtBefore.sub(usdtAfter);
+
+      const tolerance = borrowBalance.mul(1).div(100); // 1% tolerance for interest
+      expect(actualRepaid).to.be.closeTo(borrowBalance, tolerance);
+    });
+  });
+
+  describe("Liquidation path", async () => {
+    let borrower: any;
+    let borrowerAddress: string;
+    let liquidator: any;
+    let liquidatorAddress: string;
+
+    before(async () => {
+      const usdcWhale = await initMainnetUser(USDC_WHALE, ethers.utils.parseEther("1"));
+      const usdtWhale = await initMainnetUser(USDT_WHALE, ethers.utils.parseEther("1"));
+
+      const signers = await ethers.getSigners();
+      borrower = signers[2];
+      borrowerAddress = await borrower.getAddress();
+      liquidator = signers[3];
+      liquidatorAddress = await liquidator.getAddress();
+
+      await usdc.connect(usdcWhale).transfer(borrowerAddress, parseUnits("1000", 18));
+      await usdt.connect(usdtWhale).transfer(liquidatorAddress, parseUnits("10000", 18));
+
+      // Borrower: supply USDC collateral and borrow USDT near max
+      await usdc.connect(borrower).approve(VUSDC_ADDRESS, parseUnits("1000", 18));
+      await vUSDC.connect(borrower).mint(parseUnits("1000", 18));
+      await comptroller.connect(borrower).enterMarkets([VUSDC_ADDRESS]);
+      await vUSDT.connect(borrower).borrow(parseUnits("750", 18));
+    });
+
+    it("liquidateBorrow should work with the new implementation", async () => {
+      // Advance blocks to accrue interest and push borrower into shortfall
+      for (let i = 0; i < 100000; i++) {
+        await ethers.provider.send("evm_mine", []);
+      }
+      await vUSDT.connect(liquidator).accrueInterest();
+
+      const [, , shortfall] = await comptroller.getAccountLiquidity(borrowerAddress);
+
+      if (shortfall.gt(0)) {
+        const borrowBalance = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+        const repayAmount = borrowBalance.div(2);
+
+        await usdt.connect(liquidator).approve(VUSDT_ADDRESS, repayAmount);
+        await vUSDT.connect(liquidator).liquidateBorrow(borrowerAddress, repayAmount, VUSDC_ADDRESS);
+
+        const borrowAfter = await vUSDT.callStatic.borrowBalanceCurrent(borrowerAddress);
+        expect(borrowAfter).to.be.lt(borrowBalance);
+      } else {
+        console.log("Borrower not yet in shortfall after mining blocks, skipping liquidation test");
+      }
+    });
+  });
+
+  describe("generic tests", async () => {
+    checkCorePoolComptroller({
+      account: GENERIC_ETH_ACCOUNT,
+      lens: COMPTROLLER_LENS,
+    });
+  });
+});

simulations/vip-610/bsctestnet.ts

@@ -0,0 +1,39 @@
+import { TransactionResponse } from "@ethersproject/providers";
+import { expect } from "chai";
+import { ethers } from "hardhat";
+import { expectEvents } from "src/utils";
+import { forking, testVip } from "src/vip-framework";
+
+import vip596Testnet, { CORE_MARKETS, NEW_VBEP20_DELEGATE_IMPL } from "../../vips/vip-610/bsctestnet";
+import VBEP20_DELEGATOR_ABI from "./abi/VBep20Delegator.json";
+
+// TODO: Set the correct block number
+const BLOCK_NUMBER = 92753245;
+
+forking(BLOCK_NUMBER, async () => {
+  describe("Pre-VIP state", async () => {
+    it("markets should have old implementation", async () => {
+      for (const market of CORE_MARKETS) {
+        const marketContract = await ethers.getContractAt(VBEP20_DELEGATOR_ABI, market.address);
+        const currentImpl = await marketContract.implementation();
+        expect(currentImpl).to.not.equal(NEW_VBEP20_DELEGATE_IMPL);
+      }
+    });
+  });
+
+  testVip("VIP-596 testnet", await vip596Testnet(), {
+    callbackAfterExecution: async (txResponse: TransactionResponse) => {
+      const totalMarkets = CORE_MARKETS.length;
+      await expectEvents(txResponse, [VBEP20_DELEGATOR_ABI], ["NewImplementation"], [totalMarkets]);
+    },
+  });
+
+  describe("Post-VIP state", async () => {
+    it("markets should have new implementation", async () => {
+      for (const market of CORE_MARKETS) {
+        const marketContract = await ethers.getContractAt(VBEP20_DELEGATOR_ABI, market.address);
+        expect(await marketContract.implementation()).to.equal(NEW_VBEP20_DELEGATE_IMPL);
+      }
+    });
+  });
+});