aave-protocol-v2/test/helpers/utils/calculations.ts
2020-09-14 11:13:53 +02:00

1229 lines
40 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>;
}
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.principalStableDebt = userDataBeforeAction.principalStableDebt;
expectedUserData.principalVariableDebt = userDataBeforeAction.principalVariableDebt;
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
expectedUserData.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = userDataBeforeAction.stableRateLastUpdated;
expectedUserData.liquidityRate = reserveDataAfterAction.liquidityRate;
expectedUserData.scaledATokenBalance = calcExpectedScaledATokenBalance(
userDataBeforeAction,
reserveDataAfterAction.liquidityIndex,
new BigNumber(amountDeposited),
new BigNumber(0)
);
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
).plus(amountDeposited);
if (userDataBeforeAction.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = true;
} else {
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
}
expectedUserData.variableBorrowIndex = userDataBeforeAction.variableBorrowIndex;
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.minus(amountDeposited);
expectedUserData.currentStableDebt = expectedUserData.principalStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentVariableDebt = expectedUserData.principalStableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
return expectedUserData;
};
export const calcExpectedUserDataAfterWithdraw = (
amountWithdrawn: string,
reserveDataBeforeAction: ReserveData,
reserveDataAfterAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber,
currentTimestamp: BigNumber,
txCost: BigNumber
): UserReserveData => {
const expectedUserData = <UserReserveData>{};
const aTokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
if (amountWithdrawn == MAX_UINT_AMOUNT) {
amountWithdrawn = aTokenBalance.toFixed(0);
}
expectedUserData.scaledATokenBalance = calcExpectedScaledATokenBalance(
userDataBeforeAction,
reserveDataAfterAction.liquidityIndex,
new BigNumber(0),
new BigNumber(amountWithdrawn)
);
expectedUserData.currentATokenBalance = aTokenBalance.minus(amountWithdrawn);
expectedUserData.principalStableDebt = userDataBeforeAction.principalStableDebt;
expectedUserData.principalVariableDebt = userDataBeforeAction.principalVariableDebt;
expectedUserData.currentStableDebt = calcExpectedStableDebtTokenBalance(
userDataBeforeAction,
txTimestamp
);
expectedUserData.currentVariableDebt = calcExpectedVariableDebtTokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
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 the user is withdrawing everything, usageAsCollateralEnabled must be false
if (expectedUserData.currentATokenBalance.eq(0)) {
expectedUserData.usageAsCollateralEnabled = false;
} else {
expectedUserData.usageAsCollateralEnabled = userDataBeforeAction.usageAsCollateralEnabled;
}
}
expectedUserData.walletBalance = userDataBeforeAction.walletBalance.plus(amountWithdrawn);
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 calcExpectedReserveDataAfterWithdraw = (
amountWithdrawn: string,
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
txTimestamp: BigNumber
): ReserveData => {
const expectedReserveData: ReserveData = <ReserveData>{};
expectedReserveData.address = reserveDataBeforeAction.address;
if (amountWithdrawn == MAX_UINT_AMOUNT) {
amountWithdrawn = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
).toFixed();
}
expectedReserveData.totalLiquidity = new BigNumber(reserveDataBeforeAction.totalLiquidity).minus(
amountWithdrawn
);
expectedReserveData.availableLiquidity = new BigNumber(
reserveDataBeforeAction.availableLiquidity
).minus(amountWithdrawn);
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);
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.scaledATokenBalance = userDataBeforeAction.scaledATokenBalance;
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.stableBorrowRate = userDataBeforeAction.stableBorrowRate;
expectedUserData.stableRateLastUpdated = txTimestamp;
}
} 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.scaledATokenBalance = userDataBeforeAction.scaledATokenBalance;
if (user === onBehalfOf) {
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;
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
);
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;
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;
expectedUserData.stableBorrowRate = reserveDataBeforeAction.stableBorrowRate;
expectedUserData.liquidityRate = expectedDataAfterAction.liquidityRate;
expectedUserData.currentATokenBalance = calcExpectedATokenBalance(
reserveDataBeforeAction,
userDataBeforeAction,
txTimestamp
);
return expectedUserData;
};
const calcExpectedScaledATokenBalance = (
userDataBeforeAction: UserReserveData,
index: BigNumber,
amountAdded: BigNumber,
amountTaken: BigNumber
) => {
return userDataBeforeAction.scaledATokenBalance
.plus(amountAdded.rayDiv(index))
.minus(amountTaken.rayDiv(index));
};
const calcExpectedATokenBalance = (
reserveDataBeforeAction: ReserveData,
userDataBeforeAction: UserReserveData,
currentTimestamp: BigNumber
) => {
const index = calcExpectedReserveNormalizedIncome(reserveDataBeforeAction, currentTimestamp);
const {
scaledATokenBalance: scaledBalanceBeforeAction,
} = userDataBeforeAction;
return scaledBalanceBeforeAction.rayMul(index);
};
const calcExpectedAverageStableBorrowRate = (
avgStableRateBefore: BigNumber,
totalBorrowsStableBefore: BigNumber,
amountChanged: string | BigNumber,
rate: BigNumber
) => {
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);
if (timeDifference.eq(0)) {
return new BigNumber(RAY);
}
const expMinusOne = timeDifference.minus(1);
const expMinusTwo = timeDifference.gt(2) ? timeDifference.minus(2) : 0;
const ratePerSecond = rate.div(ONE_YEAR);
const basePowerTwo = ratePerSecond.rayMul(ratePerSecond);
const basePowerThree = basePowerTwo.rayMul(ratePerSecond);
const secondTerm = timeDifference.times(expMinusOne).times(basePowerTwo).div(2);
const thirdTerm = timeDifference
.times(expMinusOne)
.times(expMinusTwo)
.times(basePowerThree)
.div(6);
return new BigNumber(RAY)
.plus(ratePerSecond.times(timeDifference))
.plus(secondTerm)
.plus(thirdTerm);
};
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 totalBorrowsVariable is 0, nothing to compound
if (reserveData.totalBorrowsVariable.eq('0')) {
return reserveData.variableBorrowIndex;
}
const cumulatedInterest = calcCompoundedInterest(
reserveData.variableBorrowRate,
timestamp,
reserveData.lastUpdateTimestamp
);
return cumulatedInterest.rayMul(reserveData.variableBorrowIndex);
};