aave-protocol-v2/test/helpers/utils/calculations.ts
2020-07-08 17:26:50 +02:00

1526 lines
50 KiB
TypeScript

import BigNumber from 'bignumber.js';
import {
ONE_YEAR,
RAY,
MAX_UINT_AMOUNT,
OPTIMAL_UTILIZATION_RATE,
EXCESS_UTILIZATION_RATE,
ZERO_ADDRESS,
} from '../../../helpers/constants';
import {IReserveParams, iAavePoolAssets, RateMode} from '../../../helpers/types';
import './math';
import {ReserveData, UserReserveData} from './interfaces';
export const strToBN = (amount: string): BigNumber => new BigNumber(amount);
interface Configuration {
reservesParams: iAavePoolAssets<IReserveParams>;
ethereumAddress: string;
}
export const configuration: Configuration = <Configuration>{};
export const calcExpectedUserDataAfterDeposit = (
amountDeposited: string,
reserveDataBeforeAction: ReserveData,
reserveDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = <UserReserveData>{};
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentVariableDebt = expectedUserData.principalStableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.principalATokenBalance = userDataBeforeAction.principalStableDebt;
expectedUserData.principalVariableDebt =
userDataBeforeAction.principalVariableDebt;
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
expectedUserData.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = userDataBeforeAction.stableRateLastUpdated;
expectedUserData.liquidityRate = reserveDataAfterAction.liquidityRate;
expectedUserData.currentATokenBalance = userDataBeforeAction.currentATokenBalance.plus(
amountDeposited
);
if (userDataBeforeAction.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = true;
} else {
//if user is redeeming everything, usageAsCollateralEnabled must be false
if (expectedUserData.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = false;
} else {
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
}
}
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
// console.log("** ETH CASE ****")
expectedUserData.walletBalance = userDataBeforeAction.walletBalance
.minus(txCost)
.minus(amountDeposited);
} else {
// console.log("** TOKEN CASE ****")
// console.log(userDataBeforeAction.walletBalance.toString())
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(amountDeposited);
}
expectedUserData.principalATokenBalance = expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
).plus(amountDeposited);
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
expectedUserData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedUserData.currentATokenBalance,
expectedUserData.redirectedBalance,
txTimestamp
);
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentVariableDebt = expectedUserData.principalStableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.redirectionAddressRedirectedBalance = calcExpectedRedirectedBalance(
userDataBeforeAction,
expectedUserData,
userDataBeforeAction.redirectionAddressRedirectedBalance,
new BigNumber(amountDeposited),
new BigNumber(0)
);
return expectedUserData;
};
export const calcExpectedUserDataAfterRedeem = (
amountRedeemed: string,
reserveDataBeforeAction: ReserveData,
reserveDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = <UserReserveData>{};
const aTokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
if (amountRedeemed == MAX_UINT_AMOUNT) {
amountRedeemed = aTokenBalance.toFixed(0);
}
expectedUserData.principalATokenBalance = expectedUserData.currentATokenBalance = aTokenBalance.minus(
amountRedeemed
);
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentVariableDebt = expectedUserData.principalStableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.principalStableDebt = userDataBeforeAction.principalStableDebt;
expectedUserData.principalVariableDebt =
userDataBeforeAction.principalVariableDebt;
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
expectedUserData.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = userDataBeforeAction.stableRateLastUpdated;
expectedUserData.liquidityRate = reserveDataAfterAction.liquidityRate;
if (userDataBeforeAction.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = true;
} else {
//if user is redeeming everything, usageAsCollateralEnabled must be false
if (expectedUserData.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = false;
} else {
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
}
}
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance
.minus(txCost)
.plus(amountRedeemed);
} else {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.plus(amountRedeemed);
}
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
if (expectedUserData.currentATokenBalance.eq(0) && expectedUserData.redirectedBalance.eq(0)) {
expectedUserData.interestRedirectionAddress = ZERO_ADDRESS;
} else {
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
}
expectedUserData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedUserData.currentATokenBalance,
expectedUserData.redirectedBalance,
txTimestamp
);
expectedUserData.redirectionAddressRedirectedBalance = calcExpectedRedirectedBalance(
userDataBeforeAction,
expectedUserData,
userDataBeforeAction.redirectionAddressRedirectedBalance,
new BigNumber(0),
new BigNumber(amountRedeemed)
);
return expectedUserData;
};
export const calcExpectedReserveDataAfterDeposit = (
amountDeposited: string,
reserveDataBeforeAction: ReserveData,
txTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
expectedReserveData.totalLiquidity = new BigNumber(reserveDataBeforeAction.totalLiquidity).plus(
amountDeposited
);
expectedReserveData.availableLiquidity = new BigNumber(
reserveDataBeforeAction.availableLiquidity
).plus(amountDeposited);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable;
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable;
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
return expectedReserveData;
};
export const calcExpectedReserveDataAfterRedeem = (
amountRedeemed: string,
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
if (amountRedeemed == MAX_UINT_AMOUNT) {
amountRedeemed = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
).toFixed();
}
expectedReserveData.totalLiquidity = new BigNumber(reserveDataBeforeAction.totalLiquidity).minus(
amountRedeemed
);
expectedReserveData.availableLiquidity = new BigNumber(
reserveDataBeforeAction.availableLiquidity
).minus(amountRedeemed);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable;
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable;
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
return expectedReserveData;
};
export const calcExpectedReserveDataAfterBorrow = (
amountBorrowed: string,
borrowRateMode: string,
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber
): ReserveData => {
const expectedReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
const amountBorrowedBN = new BigNumber(amountBorrowed);
const userStableBorrowBalance = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
const userVariableBorrowBalance = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
if (borrowRateMode == RateMode.Stable) {
const debtAccrued = userStableBorrowBalance.minus(
userDataBeforeAction.principalStableDebt
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable
.plus(amountBorrowedBN)
.plus(debtAccrued);
expectedReserveData.averageStableBorrowRate = calcExpectedAverageStableBorrowRate(
reserveDataBeforeAction.averageStableBorrowRate,
reserveDataBeforeAction.totalBorrowsStable.plus(debtAccrued),
amountBorrowedBN,
reserveDataBeforeAction.stableBorrowRate
);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable;
} else {
const debtAccrued = userVariableBorrowBalance.minus(
userDataBeforeAction.principalVariableDebt
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable
.plus(amountBorrowedBN)
.plus(debtAccrued);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable;
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
}
expectedReserveData.availableLiquidity = reserveDataBeforeAction.availableLiquidity.minus(
amountBorrowedBN
);
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.lastUpdateTimestamp = txTimestamp;
return expectedReserveData;
};
export const calcExpectedReserveDataAfterRepay = (
amountRepaid: string,
borrowRateMode: RateMode,
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
let amountRepaidBN = new BigNumber(amountRepaid);
const userStableBorrowBalance = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
const userVariableBorrowBalance = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
//if amount repaid = MAX_UINT_AMOUNT, user is repaying everything
if (amountRepaidBN.abs().eq(MAX_UINT_AMOUNT)) {
if (borrowRateMode == RateMode.Stable) {
amountRepaidBN = userStableBorrowBalance;
} else {
amountRepaidBN = userVariableBorrowBalance;
}
}
if (borrowRateMode == RateMode.Stable) {
const debtAccrued = userStableBorrowBalance.minus(
userDataBeforeAction.principalStableDebt
);
console.log(
'Debt accrued: ',
debtAccrued.toFixed(),
' Total liquidity:',
reserveDataBeforeAction.totalLiquidity.toFixed(),
' total borrow stable: ',
reserveDataBeforeAction.totalBorrowsStable.toFixed()
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable
.minus(amountRepaidBN)
.plus(debtAccrued);
expectedReserveData.averageStableBorrowRate = calcExpectedAverageStableBorrowRate(
reserveDataBeforeAction.averageStableBorrowRate,
reserveDataBeforeAction.totalBorrowsStable.plus(debtAccrued),
amountRepaidBN.negated(),
userDataBeforeAction.stableBorrowRate
);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable;
} else {
const debtAccrued = userVariableBorrowBalance.minus(
userDataBeforeAction.principalVariableDebt
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable
.plus(debtAccrued)
.minus(amountRepaidBN);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable;
expectedReserveData.averageStableBorrowRate = reserveDataBeforeAction.averageStableBorrowRate;
}
expectedReserveData.availableLiquidity = reserveDataBeforeAction.availableLiquidity.plus(
amountRepaidBN
);
expectedReserveData.availableLiquidity = reserveDataBeforeAction.availableLiquidity.plus(
amountRepaidBN
);
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.lastUpdateTimestamp = txTimestamp;
return expectedReserveData;
};
export const calcExpectedUserDataAfterBorrow = (
amountBorrowed: string,
interestRateMode: string,
reserveDataBeforeAction: ReserveData,
expectedDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = <UserReserveData>{};
const currentStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
const currentVariableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
if (interestRateMode == RateMode.Stable) {
const debtAccrued = currentStableDebt.minus(
userDataBeforeAction.principalStableDebt
);
expectedUserData.principalStableDebt = currentStableDebt.plus(amountBorrowed);
expectedUserData.principalVariableDebt =
userDataBeforeAction.principalVariableDebt;
expectedUserData.stableBorrowRate = calcExpectedUserStableRate(
userDataBeforeAction.principalStableDebt.plus(debtAccrued),
userDataBeforeAction.stableBorrowRate,
new BigNumber(amountBorrowed),
reserveDataBeforeAction.stableBorrowRate
);
expectedUserData.stableRateLastUpdated = txTimestamp;
} else {
expectedUserData.principalVariableDebt = currentVariableDebt.plus(
amountBorrowed
);
expectedUserData.principalStableDebt =
userDataBeforeAction.principalStableDebt;
expectedUserData.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = userDataBeforeAction.stableRateLastUpdated;
}
expectedUserData.currentStableDebt = calcExpectedStableDebtTokenBalance(
{
...userDataBeforeAction,
currentStableDebt: expectedUserData.principalStableDebt,
principalStableDebt: expectedUserData.principalStableDebt,
stableBorrowRate: expectedUserData.stableBorrowRate,
stableRateLastUpdated: expectedUserData.stableRateLastUpdated,
},
currentTimestamp
);
expectedUserData.currentVariableDebt = calcExpectedVariableDebtTokenBalance(
expectedDataAfterAction,
{
...userDataBeforeAction,
currentVariableDebt: expectedUserData.principalVariableDebt,
principalVariableDebt: expectedUserData.principalVariableDebt,
variableBorrowIndex:
interestRateMode == RateMode.Variable
? expectedDataAfterAction.variableBorrowIndex
: userDataBeforeAction.variableBorrowIndex,
},
currentTimestamp
);
if (expectedUserData.principalVariableDebt.eq(0)) {
expectedUserData.variableBorrowIndex = new BigNumber(0);
} else {
expectedUserData.variableBorrowIndex =
interestRateMode == RateMode.Variable
? expectedDataAfterAction.variableBorrowIndex
: userDataBeforeAction.variableBorrowIndex;
}
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
expectedDataAfterAction,
userDataBeforeAction,
currentTimestamp
);
expectedUserData.principalATokenBalance = userDataBeforeAction.principalATokenBalance;
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
expectedUserData.redirectionAddressRedirectedBalance =
userDataBeforeAction.redirectionAddressRedirectedBalance;
expectedUserData.currentATokenUserIndex = userDataBeforeAction.currentATokenUserIndex;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance
.minus(txCost)
.plus(amountBorrowed);
} else {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.plus(amountBorrowed);
}
return expectedUserData;
};
export const calcExpectedUserDataAfterRepay = (
totalRepaid: string,
rateMode: RateMode,
reserveDataBeforeAction: ReserveData,
expectedDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
user: string,
onBehalfOf: string,
txTimestamp: BigNumber,
currentTimestamp: BigNumber,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = <UserReserveData>{};
const variableBorrowBalance = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
currentTimestamp
);
const stableBorrowBalance = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
currentTimestamp
);
if (new BigNumber(totalRepaid).abs().eq(MAX_UINT_AMOUNT)) {
totalRepaid =
rateMode == RateMode.Stable
? stableBorrowBalance.toFixed(0)
: variableBorrowBalance.toFixed();
}
if (rateMode == RateMode.Stable) {
expectedUserData.principalVariableDebt =
userDataBeforeAction.principalVariableDebt;
expectedUserData.currentVariableDebt = variableBorrowBalance;
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = stableBorrowBalance.minus(
totalRepaid
);
if (expectedUserData.currentStableDebt.eq('0')) {
//user repaid everything
expectedUserData.stableBorrowRate = expectedUserData.stableRateLastUpdated = new BigNumber(
'0'
);
}
} else {
expectedUserData.currentStableDebt = stableBorrowBalance;
expectedUserData.principalStableDebt =
userDataBeforeAction.principalStableDebt;
expectedUserData.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = userDataBeforeAction.stableRateLastUpdated;
expectedUserData.currentVariableDebt = expectedUserData.principalVariableDebt = variableBorrowBalance.minus(
totalRepaid
);
if (expectedUserData.currentVariableDebt.eq('0')) {
//user repaid everything
expectedUserData.variableBorrowIndex = new BigNumber('0');
} else {
expectedUserData.variableBorrowIndex = expectedDataAfterAction.variableBorrowIndex;
}
}
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.principalATokenBalance = userDataBeforeAction.principalATokenBalance;
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
expectedUserData.redirectionAddressRedirectedBalance =
userDataBeforeAction.redirectionAddressRedirectedBalance;
expectedUserData.currentATokenUserIndex = userDataBeforeAction.currentATokenUserIndex;
if (user === onBehalfOf) {
//if user repaid for himself, update the wallet balances
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance
.minus(txCost)
.minus(totalRepaid);
} else {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(totalRepaid);
}
} else {
//wallet balance didn't change
expectedUserData.walletBalance = userDataBeforeAction.walletBalance;
}
return expectedUserData;
};
export const calcExpectedUserDataAfterSetUseAsCollateral = (
useAsCollateral: boolean,
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = {...userDataBeforeAction};
expectedUserData.usageAsCollateralEnabled = useAsCollateral;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(txCost);
}
return expectedUserData;
};
export const calcExpectedReserveDataAfterSwapRateMode = (
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
rateMode: string,
txTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
const variableBorrowBalance = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
const stableBorrowBalance = calcExpectedStableDebtTokenBalance(userDataBeforeAction, txTimestamp);
expectedReserveData.availableLiquidity = reserveDataBeforeAction.availableLiquidity;
if (rateMode === RateMode.Stable) {
//swap user stable debt to variable
const debtAccrued = stableBorrowBalance.minus(
userDataBeforeAction.principalStableDebt
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.averageStableBorrowRate = calcExpectedAverageStableBorrowRate(
reserveDataBeforeAction.averageStableBorrowRate,
reserveDataBeforeAction.totalBorrowsStable.plus(debtAccrued),
stableBorrowBalance.negated(),
userDataBeforeAction.stableBorrowRate
);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable.plus(
stableBorrowBalance
);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable.minus(
userDataBeforeAction.principalStableDebt
);
} else {
const debtAccrued = variableBorrowBalance.minus(
userDataBeforeAction.principalVariableDebt
);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable.minus(
userDataBeforeAction.principalVariableDebt
);
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable.plus(
variableBorrowBalance
);
expectedReserveData.averageStableBorrowRate = calcExpectedAverageStableBorrowRate(
reserveDataBeforeAction.averageStableBorrowRate,
reserveDataBeforeAction.totalBorrowsStable,
variableBorrowBalance,
reserveDataBeforeAction.stableBorrowRate
);
}
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
return expectedReserveData;
};
export const calcExpectedUserDataAfterSwapRateMode = (
reserveDataBeforeAction: ReserveData,
expectedDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
rateMode: string,
txCost: BigNumber,
txTimestamp: BigNumber
): UserReserveData => {
const expectedUserData = {...userDataBeforeAction};
const variableBorrowBalance = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
const stableBorrowBalance = calcExpectedStableDebtTokenBalance(userDataBeforeAction, txTimestamp);
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.principalATokenBalance = userDataBeforeAction.principalATokenBalance;
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
expectedUserData.redirectionAddressRedirectedBalance =
userDataBeforeAction.redirectionAddressRedirectedBalance;
expectedUserData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedUserData.currentATokenBalance,
expectedUserData.redirectedBalance,
txTimestamp
);
if (rateMode === RateMode.Stable) {
// swap to variable
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = new BigNumber(
0
);
expectedUserData.stableBorrowRate = new BigNumber(0);
expectedUserData.principalVariableDebt = expectedUserData.currentVariableDebt = userDataBeforeAction.currentVariableDebt.plus(
stableBorrowBalance
);
expectedUserData.variableBorrowIndex = expectedDataAfterAction.variableBorrowIndex;
expectedUserData.stableRateLastUpdated = new BigNumber(0);
} else {
expectedUserData.principalStableDebt = expectedUserData.currentStableDebt = userDataBeforeAction.currentStableDebt.plus(
variableBorrowBalance
);
//weighted average of the previous and the current
expectedUserData.stableBorrowRate = calcExpectedUserStableRate(
userDataBeforeAction.principalStableDebt,
userDataBeforeAction.stableBorrowRate,
variableBorrowBalance,
reserveDataBeforeAction.stableBorrowRate
);
expectedUserData.stableRateLastUpdated = txTimestamp;
expectedUserData.currentVariableDebt = expectedUserData.principalVariableDebt = new BigNumber(
0
);
expectedUserData.variableBorrowIndex = new BigNumber(0);
}
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(txCost);
}
return expectedUserData;
};
export const calcExpectedReserveDataAfterStableRateRebalance = (
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
const stableBorrowBalance = calcExpectedStableDebtTokenBalance(userDataBeforeAction, txTimestamp);
const debtAccrued = stableBorrowBalance.minus(userDataBeforeAction.principalStableDebt);
expectedReserveData.totalLiquidity = reserveDataBeforeAction.totalLiquidity.plus(debtAccrued);
expectedReserveData.availableLiquidity = reserveDataBeforeAction.availableLiquidity;
//removing the stable liquidity at the old rate
const avgRateBefore = calcExpectedAverageStableBorrowRate(
reserveDataBeforeAction.averageStableBorrowRate,
reserveDataBeforeAction.totalBorrowsStable.plus(debtAccrued),
stableBorrowBalance.negated(),
userDataBeforeAction.stableBorrowRate
);
// adding it again at the new rate
expectedReserveData.averageStableBorrowRate = calcExpectedAverageStableBorrowRate(
avgRateBefore,
reserveDataBeforeAction.totalBorrowsStable.minus(userDataBeforeAction.principalStableDebt),
stableBorrowBalance,
reserveDataBeforeAction.stableBorrowRate
);
expectedReserveData.totalBorrowsVariable = reserveDataBeforeAction.totalBorrowsVariable;
expectedReserveData.totalBorrowsStable = reserveDataBeforeAction.totalBorrowsStable.plus(debtAccrued);
expectedReserveData.utilizationRate = calcExpectedUtilizationRate(
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.totalLiquidity
);
const rates = calcExpectedInterestRates(
reserveDataBeforeAction.symbol,
reserveDataBeforeAction.marketStableRate,
expectedReserveData.utilizationRate,
expectedReserveData.totalBorrowsStable,
expectedReserveData.totalBorrowsVariable,
expectedReserveData.averageStableBorrowRate
);
expectedReserveData.liquidityRate = rates[0];
expectedReserveData.stableBorrowRate = rates[1];
expectedReserveData.variableBorrowRate = rates[2];
expectedReserveData.liquidityIndex = calcExpectedLiquidityIndex(
reserveDataBeforeAction,
txTimestamp
);
expectedReserveData.variableBorrowIndex = calcExpectedVariableBorrowIndex(
reserveDataBeforeAction,
txTimestamp
);
return expectedReserveData;
};
export const calcExpectedUserDataAfterStableRateRebalance = (
reserveDataBeforeAction: ReserveData,
expectedDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
txCost: BigNumber,
txTimestamp: BigNumber
): UserReserveData => {
const expectedUserData = {...userDataBeforeAction};
expectedUserData.principalVariableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.stableRateLastUpdated = txTimestamp;
expectedUserData.principalVariableDebt =
userDataBeforeAction.principalVariableDebt;
const debtAccrued = expectedUserData.currentStableDebt.minus(
userDataBeforeAction.principalStableDebt
);
expectedUserData.stableBorrowRate = reserveDataBeforeAction.stableBorrowRate;
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(txCost);
}
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
expectedUserData.principalATokenBalance = userDataBeforeAction.principalATokenBalance;
expectedUserData.redirectedBalance = userDataBeforeAction.redirectedBalance;
expectedUserData.interestRedirectionAddress = userDataBeforeAction.interestRedirectionAddress;
expectedUserData.redirectionAddressRedirectedBalance =
userDataBeforeAction.redirectionAddressRedirectedBalance;
expectedUserData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedUserData.currentATokenBalance,
expectedUserData.redirectedBalance,
txTimestamp
);
return expectedUserData;
};
export const calcExpectedUsersDataAfterRedirectInterest = (
reserveDataBeforeAction: ReserveData,
fromDataBeforeAction: UserReserveData,
toDataBeforeAction: UserReserveData,
fromAddress: string,
toAddress: string,
isFromExecutingTx: boolean,
txCost: BigNumber,
txTimestamp: BigNumber
): UserReserveData[] => {
const expectedFromData = {...fromDataBeforeAction};
const expectedToData = {...toDataBeforeAction};
expectedFromData.currentStableDebt = calcExpectedStableDebtTokenBalance(
fromDataBeforeAction,
txTimestamp
);
expectedToData.currentVariableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
toDataBeforeAction,
txTimestamp
);
expectedFromData.variableBorrowIndex = fromDataBeforeAction.variableBorrowIndex;
expectedToData.variableBorrowIndex = toDataBeforeAction.variableBorrowIndex;
expectedFromData.stableBorrowRate = fromDataBeforeAction.stableBorrowRate;
expectedToData.stableBorrowRate = toDataBeforeAction.stableBorrowRate;
expectedFromData.principalATokenBalance = expectedFromData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
fromDataBeforeAction,
txTimestamp
);
expectedToData.principalATokenBalance = expectedToData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
toDataBeforeAction,
txTimestamp
);
if (isFromExecutingTx) {
if (reserveDataBeforeAction.address === configuration.ethereumAddress) {
expectedFromData.walletBalance = fromDataBeforeAction.walletBalance.minus(txCost);
}
}
expectedToData.redirectedBalance = toDataBeforeAction.redirectedBalance.plus(
expectedFromData.currentATokenBalance
);
if (fromAddress === toAddress) {
expectedFromData.interestRedirectionAddress = ZERO_ADDRESS;
expectedFromData.redirectedBalance = new BigNumber(0);
expectedFromData.redirectionAddressRedirectedBalance = new BigNumber(0);
expectedToData.interestRedirectionAddress = ZERO_ADDRESS;
expectedToData.redirectedBalance = new BigNumber(0);
expectedToData.redirectionAddressRedirectedBalance = new BigNumber(0);
} else {
expectedFromData.interestRedirectionAddress = toAddress;
expectedFromData.redirectionAddressRedirectedBalance = calcExpectedRedirectedBalance(
toDataBeforeAction,
expectedFromData,
toDataBeforeAction.redirectedBalance,
expectedFromData.currentATokenBalance,
new BigNumber(0)
);
}
expectedFromData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedFromData.currentATokenBalance,
expectedFromData.redirectedBalance,
txTimestamp
);
expectedToData.currentATokenUserIndex = calcExpectedATokenUserIndex(
reserveDataBeforeAction,
expectedToData.currentATokenBalance,
expectedToData.redirectedBalance,
txTimestamp
);
return [expectedFromData, expectedToData];
};
const calcExpectedATokenUserIndex = (
reserveDataBeforeAction: ReserveData,
expectedUserBalanceAfterAction: BigNumber,
expectedUserRedirectedBalanceAterAction: BigNumber,
currentTimestamp: BigNumber
) => {
if (expectedUserBalanceAfterAction.eq(0) && expectedUserRedirectedBalanceAterAction.eq(0)) {
return new BigNumber(0);
}
return calcExpectedReserveNormalizedIncome(reserveDataBeforeAction, currentTimestamp);
};
const calcExpectedATokenBalance = (
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
currentTimestamp: BigNumber
) => {
const income = calcExpectedReserveNormalizedIncome(reserveDataBeforeAction, currentTimestamp);
const {
interestRedirectionAddress,
currentATokenUserIndex: userIndexBeforeAction,
redirectedBalance,
principalATokenBalance: principalBalanceBeforeAction,
} = userDataBeforeAction;
if (userIndexBeforeAction.eq(0)) {
return principalBalanceBeforeAction;
}
if (interestRedirectionAddress === ZERO_ADDRESS) {
return principalBalanceBeforeAction
.plus(redirectedBalance)
.wadToRay()
.rayMul(income)
.rayDiv(userIndexBeforeAction)
.rayToWad()
.minus(redirectedBalance);
} else {
return principalBalanceBeforeAction.plus(
redirectedBalance
.wadToRay()
.rayMul(income)
.rayDiv(userIndexBeforeAction)
.rayToWad()
.minus(redirectedBalance)
);
}
};
const calcExpectedRedirectedBalance = (
userDataBeforeAction: UserReserveData,
expectedUserDataAfterAction: UserReserveData,
redirectedBalanceBefore: BigNumber,
amountToAdd: BigNumber,
amountToSubstract: BigNumber
): BigNumber => {
const balanceIncrease = userDataBeforeAction.currentATokenBalance.minus(
userDataBeforeAction.principalATokenBalance
);
return expectedUserDataAfterAction.interestRedirectionAddress !== ZERO_ADDRESS
? redirectedBalanceBefore.plus(balanceIncrease).plus(amountToAdd).minus(amountToSubstract)
: new BigNumber('0');
};
const calcExpectedAverageStableBorrowRate = (
avgStableRateBefore: BigNumber,
totalBorrowsStableBefore: BigNumber,
amountChanged: string | BigNumber,
rate: BigNumber
) => {
console.log(avgStableRateBefore, totalBorrowsStableBefore);
const weightedTotalBorrows = avgStableRateBefore.multipliedBy(totalBorrowsStableBefore);
const weightedAmountBorrowed = rate.multipliedBy(amountChanged);
const totalBorrowedStable = totalBorrowsStableBefore.plus(new BigNumber(amountChanged));
if (totalBorrowedStable.eq(0)) return new BigNumber('0');
return weightedTotalBorrows
.plus(weightedAmountBorrowed)
.div(totalBorrowedStable)
.decimalPlaces(0, BigNumber.ROUND_DOWN);
};
const calcExpectedVariableDebtUserIndex = (
reserveDataBeforeAction: ReserveData,
expectedUserBalanceAfterAction: BigNumber,
currentTimestamp: BigNumber
) => {
if (expectedUserBalanceAfterAction.eq(0)) {
return new BigNumber(0);
}
return calcExpectedReserveNormalizedDebt(reserveDataBeforeAction, currentTimestamp);
};
export const calcExpectedVariableDebtTokenBalance = (
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
currentTimestamp: BigNumber
) => {
const debt = calcExpectedReserveNormalizedDebt(reserveDataBeforeAction, currentTimestamp);
const {principalVariableDebt, variableBorrowIndex} = userDataBeforeAction;
if (variableBorrowIndex.eq(0)) {
return principalVariableDebt;
}
return principalVariableDebt
.wadToRay()
.rayMul(debt)
.rayDiv(variableBorrowIndex)
.rayToWad();
};
export const calcExpectedStableDebtTokenBalance = (
userDataBeforeAction: UserReserveData,
currentTimestamp: BigNumber
) => {
const {
principalStableDebt,
stableBorrowRate,
stableRateLastUpdated,
} = userDataBeforeAction;
if (
stableBorrowRate.eq(0) ||
currentTimestamp.eq(stableRateLastUpdated) ||
stableRateLastUpdated.eq(0)
) {
return principalStableDebt;
}
const cumulatedInterest = calcCompoundedInterest(
stableBorrowRate,
currentTimestamp,
stableRateLastUpdated
);
return principalStableDebt.wadToRay().rayMul(cumulatedInterest).rayToWad();
};
const calcLinearInterest = (
rate: BigNumber,
currentTimestamp: BigNumber,
lastUpdateTimestamp: BigNumber
) => {
const timeDifference = currentTimestamp.minus(lastUpdateTimestamp).wadToRay();
const timeDelta = timeDifference.rayDiv(new BigNumber(ONE_YEAR).wadToRay());
const cumulatedInterest = rate.rayMul(timeDelta).plus(RAY);
return cumulatedInterest;
};
const calcCompoundedInterest = (
rate: BigNumber,
currentTimestamp: BigNumber,
lastUpdateTimestamp: BigNumber
) => {
const timeDifference = currentTimestamp.minus(lastUpdateTimestamp);
const ratePerSecond = rate.div(ONE_YEAR);
const compoundedInterest = ratePerSecond.plus(RAY).rayPow(timeDifference);
return compoundedInterest;
};
const calcExpectedInterestRates = (
reserveSymbol: string,
marketStableRate: BigNumber,
utilizationRate: BigNumber,
totalBorrowsStable: BigNumber,
totalBorrowsVariable: BigNumber,
averageStableBorrowRate: BigNumber
): BigNumber[] => {
const {reservesParams} = configuration;
const reserveIndex = Object.keys(reservesParams).findIndex((value) => value === reserveSymbol);
const [, reserveConfiguration] = (Object.entries(reservesParams) as [string, IReserveParams][])[
reserveIndex
];
let stableBorrowRate: BigNumber = marketStableRate;
let variableBorrowRate: BigNumber = new BigNumber(reserveConfiguration.baseVariableBorrowRate);
if (utilizationRate.gt(OPTIMAL_UTILIZATION_RATE)) {
const excessUtilizationRateRatio = utilizationRate
.minus(OPTIMAL_UTILIZATION_RATE)
.rayDiv(EXCESS_UTILIZATION_RATE);
stableBorrowRate = stableBorrowRate
.plus(reserveConfiguration.stableRateSlope1)
.plus(
new BigNumber(reserveConfiguration.stableRateSlope2).rayMul(excessUtilizationRateRatio)
);
variableBorrowRate = variableBorrowRate
.plus(reserveConfiguration.variableRateSlope1)
.plus(
new BigNumber(reserveConfiguration.variableRateSlope2).rayMul(excessUtilizationRateRatio)
);
} else {
stableBorrowRate = stableBorrowRate.plus(
new BigNumber(reserveConfiguration.stableRateSlope1).rayMul(
utilizationRate.rayDiv(new BigNumber(OPTIMAL_UTILIZATION_RATE))
)
);
variableBorrowRate = variableBorrowRate.plus(
utilizationRate
.rayDiv(OPTIMAL_UTILIZATION_RATE)
.rayMul(new BigNumber(reserveConfiguration.variableRateSlope1))
);
}
const expectedOverallRate = calcExpectedOverallBorrowRate(
totalBorrowsStable,
totalBorrowsVariable,
variableBorrowRate,
averageStableBorrowRate
);
const liquidityRate = expectedOverallRate.rayMul(utilizationRate);
return [liquidityRate, stableBorrowRate, variableBorrowRate];
};
const calcExpectedOverallBorrowRate = (
totalBorrowsStable: BigNumber,
totalBorrowsVariable: BigNumber,
currentVariableBorrowRate: BigNumber,
currentAverageStableBorrowRate: BigNumber
): BigNumber => {
const totalBorrows = totalBorrowsStable.plus(totalBorrowsVariable);
if (totalBorrows.eq(0)) return strToBN('0');
const weightedVariableRate = totalBorrowsVariable.wadToRay().rayMul(currentVariableBorrowRate);
const weightedStableRate = totalBorrowsStable.wadToRay().rayMul(currentAverageStableBorrowRate);
const overallBorrowRate = weightedVariableRate
.plus(weightedStableRate)
.rayDiv(totalBorrows.wadToRay());
return overallBorrowRate;
};
const calcExpectedUtilizationRate = (
totalBorrowsStable: BigNumber,
totalBorrowsVariable: BigNumber,
totalLiquidity: BigNumber
): BigNumber => {
if (totalBorrowsStable.eq('0') && totalBorrowsVariable.eq('0')) {
return strToBN('0');
}
const utilization = totalBorrowsStable.plus(totalBorrowsVariable).rayDiv(totalLiquidity);
return utilization;
};
const calcExpectedReserveNormalizedIncome = (
reserveData: ReserveData,
currentTimestamp: BigNumber
) => {
const {liquidityRate, liquidityIndex, lastUpdateTimestamp} = reserveData;
//if utilization rate is 0, nothing to compound
if (liquidityRate.eq('0')) {
return liquidityIndex;
}
const cumulatedInterest = calcLinearInterest(
liquidityRate,
currentTimestamp,
lastUpdateTimestamp
);
const income = cumulatedInterest.rayMul(liquidityIndex);
return income;
};
const calcExpectedReserveNormalizedDebt = (
reserveData: ReserveData,
currentTimestamp: BigNumber
) => {
const {variableBorrowRate, variableBorrowIndex, lastUpdateTimestamp} = reserveData;
//if utilization rate is 0, nothing to compound
if (variableBorrowRate.eq('0')) {
return variableBorrowIndex;
}
const cumulatedInterest = calcCompoundedInterest(
variableBorrowRate,
currentTimestamp,
lastUpdateTimestamp
);
const debt = cumulatedInterest.rayMul(variableBorrowIndex);
return debt;
};
const calcExpectedUserStableRate = (
balanceBefore: BigNumber,
rateBefore: BigNumber,
amount: BigNumber,
rateNew: BigNumber
) => {
return balanceBefore
.times(rateBefore)
.plus(amount.times(rateNew))
.div(balanceBefore.plus(amount));
};
const calcExpectedLiquidityIndex = (reserveData: ReserveData, timestamp: BigNumber) => {
//if utilization rate is 0, nothing to compound
if (reserveData.utilizationRate.eq('0')) {
return reserveData.liquidityIndex;
}
const cumulatedInterest = calcLinearInterest(
reserveData.liquidityRate,
timestamp,
reserveData.lastUpdateTimestamp
);
return cumulatedInterest.rayMul(reserveData.liquidityIndex);
};
const calcExpectedVariableBorrowIndex = (reserveData: ReserveData, timestamp: BigNumber) => {
//if utilization rate is 0, nothing to compound
if (reserveData.utilizationRate.eq('0')) {
return reserveData.variableBorrowIndex;
}
const cumulatedInterest = calcCompoundedInterest(
reserveData.variableBorrowRate,
timestamp,
reserveData.lastUpdateTimestamp
);
return cumulatedInterest.rayMul(reserveData.variableBorrowIndex);
};
export const calculateHealthFactorFromBalances = (
collateralBalanceETH: BigNumber,
borrowBalanceETH: BigNumber,
currentLiquidationThreshold: BigNumber
): BigNumber => {
if (borrowBalanceETH.eq(0)) {
return strToBN('-1'); // invalid number
}
return collateralBalanceETH.multipliedBy(currentLiquidationThreshold).div(borrowBalanceETH);
};
const calculateAvailableBorrowsETH = (
collateralBalanceETH: BigNumber,
borrowBalanceETH: BigNumber,
currentLtv: BigNumber
): BigNumber => {
if (currentLtv.eq(0)) {
return strToBN('0');
}
let availableBorrowsETH = collateralBalanceETH.multipliedBy(currentLtv);
if (availableBorrowsETH.lt(borrowBalanceETH)) {
return strToBN('0');
}
availableBorrowsETH = availableBorrowsETH.minus(borrowBalanceETH);
const borrowFee = availableBorrowsETH.multipliedBy(0.0025);
return availableBorrowsETH.minus(borrowFee);
};