import BigNumber from 'bignumber.js'; import {BRE} from '../helpers/misc-utils'; import {APPROVAL_AMOUNT_LENDING_POOL, oneEther} from '../helpers/constants'; import {convertToCurrencyDecimals} from '../helpers/contracts-helpers'; import {makeSuite} from './helpers/make-suite'; import {ProtocolErrors, RateMode} from '../helpers/types'; import {calcExpectedStableDebtTokenBalance} from './helpers/utils/calculations'; import {getUserData} from './helpers/utils/helpers'; const chai = require('chai'); const {expect} = chai; makeSuite('LendingPool liquidation - liquidator receiving the underlying asset', (testEnv) => { const {INVALID_HF} = ProtocolErrors; it('LIQUIDATION - Deposits WETH, borrows DAI', async () => { const {dai, weth, users, pool, oracle} = testEnv; const depositor = users[0]; const borrower = users[1]; //mints DAI to depositor await dai.connect(depositor.signer).mint(await convertToCurrencyDecimals(dai.address, '1000')); //approve protocol to access depositor wallet await dai.connect(depositor.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); //user 1 deposits 1000 DAI const amountDAItoDeposit = await convertToCurrencyDecimals(dai.address, '1000'); await pool.connect(depositor.signer).deposit(dai.address, amountDAItoDeposit, '0'); //user 2 deposits 1 ETH const amountETHtoDeposit = await convertToCurrencyDecimals(weth.address, '1'); //mints WETH to borrower await weth.connect(borrower.signer).mint(await convertToCurrencyDecimals(weth.address, '1000')); //approve protocol to access the borrower wallet await weth.connect(borrower.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); await pool.connect(borrower.signer).deposit(weth.address, amountETHtoDeposit, '0'); //user 2 borrows const userGlobalData = await pool.getUserAccountData(borrower.address); const daiPrice = await oracle.getAssetPrice(dai.address); const amountDAIToBorrow = await convertToCurrencyDecimals( dai.address, new BigNumber(userGlobalData.availableBorrowsETH.toString()) .div(daiPrice.toString()) .multipliedBy(0.95) .toFixed(0) ); await pool .connect(borrower.signer) .borrow(dai.address, amountDAIToBorrow, RateMode.Stable, '0'); const userGlobalDataAfter = await pool.getUserAccountData(borrower.address); expect(userGlobalDataAfter.currentLiquidationThreshold.toString()).to.be.bignumber.equal( '8000', INVALID_HF ); }); it('LIQUIDATION - Drop the health factor below 1', async () => { const {dai, weth, users, pool, oracle} = testEnv; const borrower = users[1]; const daiPrice = await oracle.getAssetPrice(dai.address); await oracle.setAssetPrice( dai.address, new BigNumber(daiPrice.toString()).multipliedBy(1.25).toFixed(0) ); const userGlobalData = await pool.getUserAccountData(borrower.address); expect(userGlobalData.healthFactor.toString()).to.be.bignumber.lt( oneEther.toFixed(0), INVALID_HF ); }); it('LIQUIDATION - Liquidates the borrow', async () => { const {dai, weth, users, pool, oracle} = testEnv; const liquidator = users[3]; const borrower = users[1]; //mints dai to the liquidator await dai.connect(liquidator.signer).mint(await convertToCurrencyDecimals(dai.address, '1000')); //approve protocol to access the liquidator wallet await dai.connect(liquidator.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); const daiReserveDataBefore = await pool.getReserveData(dai.address); const ethReserveDataBefore = await pool.getReserveData(weth.address); const userReserveDataBefore = await getUserData(pool, dai.address, borrower.address); const amountToLiquidate = userReserveDataBefore.currentStableDebt.div(2).toFixed(0); const tx = await pool .connect(liquidator.signer) .liquidationCall(weth.address, dai.address, borrower.address, amountToLiquidate, false); const userReserveDataAfter = await getUserData(pool, dai.address, borrower.address); const daiReserveDataAfter = await pool.getReserveData(dai.address); const ethReserveDataAfter = await pool.getReserveData(weth.address); const collateralPrice = await oracle.getAssetPrice(weth.address); const principalPrice = await oracle.getAssetPrice(dai.address); const collateralDecimals = ( await pool.getReserveConfigurationData(weth.address) ).decimals.toString(); const principalDecimals = ( await pool.getReserveConfigurationData(dai.address) ).decimals.toString(); const expectedCollateralLiquidated = new BigNumber(principalPrice.toString()) .times(new BigNumber(amountToLiquidate).times(105)) .times(new BigNumber(10).pow(collateralDecimals)) .div( new BigNumber(collateralPrice.toString()).times(new BigNumber(10).pow(principalDecimals)) ) .div(100) .decimalPlaces(0, BigNumber.ROUND_DOWN); if (!tx.blockNumber) { expect(false, 'Invalid block number'); return; } const txTimestamp = new BigNumber( (await BRE.ethers.provider.getBlock(tx.blockNumber)).timestamp ); const stableDebtBeforeTx = calcExpectedStableDebtTokenBalance( userReserveDataBefore, txTimestamp ); expect(userReserveDataAfter.currentStableDebt.toString()).to.be.bignumber.almostEqual( stableDebtBeforeTx.minus(amountToLiquidate).toFixed(0), 'Invalid user debt after liquidation' ); //the liquidity index of the principal reserve needs to be bigger than the index before expect(daiReserveDataAfter.liquidityIndex.toString()).to.be.bignumber.gt( daiReserveDataBefore.liquidityIndex.toString(), 'Invalid liquidity index' ); //the principal APY after a liquidation needs to be lower than the APY before expect(daiReserveDataAfter.liquidityRate.toString()).to.be.bignumber.lt( daiReserveDataBefore.liquidityRate.toString(), 'Invalid liquidity APY' ); expect(daiReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(daiReserveDataBefore.availableLiquidity.toString()) .plus(amountToLiquidate) .toFixed(0), 'Invalid principal available liquidity' ); expect(ethReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(ethReserveDataBefore.availableLiquidity.toString()) .minus(expectedCollateralLiquidated) .toFixed(0), 'Invalid collateral available liquidity' ); }); it('User 3 deposits 1000 USDC, user 4 1 WETH, user 4 borrows - drops HF, liquidates the borrow', async () => { const {usdc, users, pool, oracle, weth} = testEnv; const depositor = users[3]; const borrower = users[4]; const liquidator = users[5]; //mints USDC to depositor await usdc .connect(depositor.signer) .mint(await convertToCurrencyDecimals(usdc.address, '1000')); //approve protocol to access depositor wallet await usdc.connect(depositor.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); //depositor deposits 1000 USDC const amountUSDCtoDeposit = await convertToCurrencyDecimals(usdc.address, '1000'); await pool.connect(depositor.signer).deposit(usdc.address, amountUSDCtoDeposit, '0'); //borrower deposits 1 ETH const amountETHtoDeposit = await convertToCurrencyDecimals(weth.address, '1'); //mints WETH to borrower await weth.connect(borrower.signer).mint(await convertToCurrencyDecimals(weth.address, '1000')); //approve protocol to access the borrower wallet await weth.connect(borrower.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); await pool.connect(borrower.signer).deposit(weth.address, amountETHtoDeposit, '0'); //borrower borrows const userGlobalData = await pool.getUserAccountData(borrower.address); const usdcPrice = await oracle.getAssetPrice(usdc.address); const amountUSDCToBorrow = await convertToCurrencyDecimals( usdc.address, new BigNumber(userGlobalData.availableBorrowsETH.toString()) .div(usdcPrice.toString()) .multipliedBy(0.95) .toFixed(0) ); await pool .connect(borrower.signer) .borrow(usdc.address, amountUSDCToBorrow, RateMode.Stable, '0'); //drops HF below 1 await oracle.setAssetPrice( usdc.address, new BigNumber(usdcPrice.toString()).multipliedBy(1.2).toFixed(0) ); //mints dai to the liquidator await usdc .connect(liquidator.signer) .mint(await convertToCurrencyDecimals(usdc.address, '1000')); //approve protocol to access depositor wallet await usdc.connect(liquidator.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); const userReserveDataBefore = await pool.getUserReserveData(usdc.address, borrower.address); const usdcReserveDataBefore = await pool.getReserveData(usdc.address); const ethReserveDataBefore = await pool.getReserveData(weth.address); const amountToLiquidate = new BigNumber(userReserveDataBefore.currentStableDebt.toString()) .div(2) .decimalPlaces(0, BigNumber.ROUND_DOWN) .toFixed(0); await pool .connect(liquidator.signer) .liquidationCall(weth.address, usdc.address, borrower.address, amountToLiquidate, false); const userReserveDataAfter = await pool.getUserReserveData(usdc.address, borrower.address); const userGlobalDataAfter = await pool.getUserAccountData(borrower.address); const usdcReserveDataAfter = await pool.getReserveData(usdc.address); const ethReserveDataAfter = await pool.getReserveData(weth.address); const collateralPrice = await oracle.getAssetPrice(weth.address); const principalPrice = await oracle.getAssetPrice(usdc.address); const collateralDecimals = ( await pool.getReserveConfigurationData(weth.address) ).decimals.toString(); const principalDecimals = ( await pool.getReserveConfigurationData(usdc.address) ).decimals.toString(); const expectedCollateralLiquidated = new BigNumber(principalPrice.toString()) .times(new BigNumber(amountToLiquidate).times(105)) .times(new BigNumber(10).pow(collateralDecimals)) .div( new BigNumber(collateralPrice.toString()).times(new BigNumber(10).pow(principalDecimals)) ) .div(100) .decimalPlaces(0, BigNumber.ROUND_DOWN); expect(userGlobalDataAfter.healthFactor.toString()).to.be.bignumber.gt( oneEther.toFixed(0), 'Invalid health factor' ); expect(userReserveDataAfter.currentStableDebt.toString()).to.be.bignumber.almostEqual( new BigNumber(userReserveDataBefore.currentStableDebt.toString()) .minus(amountToLiquidate) .toFixed(0), 'Invalid user borrow balance after liquidation' ); //the liquidity index of the principal reserve needs to be bigger than the index before expect(usdcReserveDataAfter.liquidityIndex.toString()).to.be.bignumber.gt( usdcReserveDataBefore.liquidityIndex.toString(), 'Invalid liquidity index' ); //the principal APY after a liquidation needs to be lower than the APY before expect(usdcReserveDataAfter.liquidityRate.toString()).to.be.bignumber.lt( usdcReserveDataBefore.liquidityRate.toString(), 'Invalid liquidity APY' ); expect(usdcReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(usdcReserveDataBefore.availableLiquidity.toString()) .plus(amountToLiquidate) .toFixed(0), 'Invalid principal available liquidity' ); expect(ethReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(ethReserveDataBefore.availableLiquidity.toString()) .minus(expectedCollateralLiquidated) .toFixed(0), 'Invalid collateral available liquidity' ); }); it('User 4 deposits 1000 LEND - drops HF, liquidates the LEND, which results on a lower amount being liquidated', async () => { const {lend, usdc, users, pool, oracle} = testEnv; const depositor = users[3]; const borrower = users[4]; const liquidator = users[5]; //mints LEND to borrower await lend.connect(borrower.signer).mint(await convertToCurrencyDecimals(lend.address, '1000')); //approve protocol to access the borrower wallet await lend.connect(borrower.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); //borrower deposits 1000 LEND const amountLENDtoDeposit = await convertToCurrencyDecimals(lend.address, '1000'); await pool.connect(borrower.signer).deposit(lend.address, amountLENDtoDeposit, '0'); const usdcPrice = await oracle.getAssetPrice(usdc.address); //drops HF below 1 await oracle.setAssetPrice( usdc.address, new BigNumber(usdcPrice.toString()).multipliedBy(1.12).toFixed(0) ); //mints usdc to the liquidator await usdc .connect(liquidator.signer) .mint(await convertToCurrencyDecimals(usdc.address, '1000')); //approve protocol to access depositor wallet await usdc.connect(liquidator.signer).approve(pool.address, APPROVAL_AMOUNT_LENDING_POOL); const userReserveDataBefore = await pool.getUserReserveData(usdc.address, borrower.address); const usdcReserveDataBefore = await pool.getReserveData(usdc.address); const lendReserveDataBefore = await pool.getReserveData(lend.address); const amountToLiquidate = new BigNumber(userReserveDataBefore.currentStableDebt.toString()) .div(2) .decimalPlaces(0, BigNumber.ROUND_DOWN) .toFixed(0); const collateralPrice = await oracle.getAssetPrice(lend.address); const principalPrice = await oracle.getAssetPrice(usdc.address); await pool .connect(liquidator.signer) .liquidationCall(lend.address, usdc.address, borrower.address, amountToLiquidate, false); const userReserveDataAfter = await pool.getUserReserveData(usdc.address, borrower.address); const userGlobalDataAfter = await pool.getUserAccountData(borrower.address); const usdcReserveDataAfter = await pool.getReserveData(usdc.address); const lendReserveDataAfter = await pool.getReserveData(lend.address); const collateralDecimals = ( await pool.getReserveConfigurationData(lend.address) ).decimals.toString(); const principalDecimals = ( await pool.getReserveConfigurationData(usdc.address) ).decimals.toString(); const expectedCollateralLiquidated = oneEther.multipliedBy('1000'); const liquidationBonus = ( await pool.getReserveConfigurationData(lend.address) ).liquidationBonus.toString(); const expectedPrincipal = new BigNumber(collateralPrice.toString()) .times(expectedCollateralLiquidated) .times(new BigNumber(10).pow(principalDecimals)) .div( new BigNumber(principalPrice.toString()).times(new BigNumber(10).pow(collateralDecimals)) ) .times(10000) .div(liquidationBonus.toString()) .decimalPlaces(0, BigNumber.ROUND_DOWN); expect(userGlobalDataAfter.healthFactor.toString()).to.be.bignumber.gt( oneEther.toFixed(0), 'Invalid health factor' ); expect(userReserveDataAfter.currentStableDebt.toString()).to.be.bignumber.almostEqual( new BigNumber(userReserveDataBefore.currentStableDebt.toString()) .minus(expectedPrincipal) .toFixed(0), 'Invalid user borrow balance after liquidation' ); expect(usdcReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(usdcReserveDataBefore.availableLiquidity.toString()) .plus(expectedPrincipal) .toFixed(0), 'Invalid principal available liquidity' ); expect(lendReserveDataAfter.availableLiquidity.toString()).to.be.bignumber.almostEqual( new BigNumber(lendReserveDataBefore.availableLiquidity.toString()) .minus(expectedCollateralLiquidated) .toFixed(0), 'Invalid collateral available liquidity' ); }); });