feat: removal of the rate oracle, initial implementation, tests fixed

contracts/interfaces/IPoolAddressesProvider.sol

@@ -11,7 +11,6 @@ interface IPoolAddressesProvider {
   event PoolUpdated(address indexed newAddress);
   event PoolConfiguratorUpdated(address indexed newAddress);
   event PriceOracleUpdated(address indexed newAddress);
-  event RateOracleUpdated(address indexed newAddress);
   event ACLManagerUpdated(address indexed newAddress);
   event ACLAdminUpdated(address indexed newAddress);
   event ProxyCreated(bytes32 id, address indexed newAddress);
@@ -85,10 +84,6 @@ interface IPoolAddressesProvider {
 
   function setPriceOracle(address priceOracle) external;
 
-  function getRateOracle() external view returns (address);
-
-  function setRateOracle(address rateOracle) external;
-
   /**
    * @notice Returns the address of the ACL manager proxy
    * @return The ACLManager proxy address

contracts/misc/AaveProtocolDataProvider.sol

@@ -303,4 +303,25 @@ contract AaveProtocolDataProvider {
       reserve.variableDebtTokenAddress
     );
   }
+
+   /**
+   * @notice Returns the address of the IR strategy
+   * @param asset The address of the underlying asset of the reserve
+   * @return irStrategyAddress The address of the IR strategy
+   */
+  function getIRStrategyAddress(address asset)
+    external
+    view
+    returns (
+      address irStrategyAddress
+    )
+  {
+    DataTypes.ReserveData memory reserve = IPool(ADDRESSES_PROVIDER.getPool()).getReserveData(
+      asset
+    );
+
+    return (
+      reserve.interestRateStrategyAddress
+    );
+  }
 }

contracts/protocol/configuration/PoolAddressesProvider.sol

@@ -19,7 +19,6 @@ contract PoolAddressesProvider is Ownable, IPoolAddressesProvider {
   bytes32 private constant POOL = 'POOL';
   bytes32 private constant POOL_CONFIGURATOR = 'POOL_CONFIGURATOR';
   bytes32 private constant PRICE_ORACLE = 'PRICE_ORACLE';
-  bytes32 private constant RATE_ORACLE = 'RATE_ORACLE';
   bytes32 private constant ACL_MANAGER = 'ACL_MANAGER';
   bytes32 private constant ACL_ADMIN = 'ACL_ADMIN';
 
@@ -89,15 +88,6 @@ contract PoolAddressesProvider is Ownable, IPoolAddressesProvider {
     emit PriceOracleUpdated(priceOracle);
   }
 
-  function getRateOracle() external view override returns (address) {
-    return getAddress(RATE_ORACLE);
-  }
-
-  function setRateOracle(address rateOracle) external override onlyOwner {
-    _addresses[RATE_ORACLE] = rateOracle;
-    emit RateOracleUpdated(rateOracle);
-  }
-
   /// @inheritdoc IPoolAddressesProvider
   function getACLManager() external view override returns (address) {
     return getAddress(ACL_MANAGER);

contracts/protocol/libraries/logic/BorrowLogic.sol

@@ -15,6 +15,7 @@ import {PercentageMath} from '../math/PercentageMath.sol';
 import {DataTypes} from '../types/DataTypes.sol';
 import {ValidationLogic} from './ValidationLogic.sol';
 import {ReserveLogic} from './ReserveLogic.sol';
+import 'hardhat/console.sol';
 
 /**
  * @title BorrowLogic library
@@ -164,6 +165,8 @@ library BorrowLogic {
       ? stableDebt
       : variableDebt;
 
+    console.log('Payback amount: ', paybackAmount);
+
     if (params.amount < paybackAmount) {
       paybackAmount = params.amount;
     }

contracts/protocol/libraries/types/DataTypes.sol

@@ -8,10 +8,10 @@ library DataTypes {
     ReserveConfigurationMap configuration;
     //the liquidity index. Expressed in ray
     uint128 liquidityIndex;
-    //variable borrow index. Expressed in ray
-    uint128 variableBorrowIndex;
     //the current supply rate. Expressed in ray
     uint128 currentLiquidityRate;
+    //variable borrow index. Expressed in ray
+    uint128 variableBorrowIndex;
     //the current variable borrow rate. Expressed in ray
     uint128 currentVariableBorrowRate;
     //the current stable borrow rate. Expressed in ray

contracts/protocol/pool/DefaultReserveInterestRateStrategy.sol

@@ -6,9 +6,9 @@ import {WadRayMath} from '../libraries/math/WadRayMath.sol';
 import {PercentageMath} from '../libraries/math/PercentageMath.sol';
 import {IReserveInterestRateStrategy} from '../../interfaces/IReserveInterestRateStrategy.sol';
 import {IPoolAddressesProvider} from '../../interfaces/IPoolAddressesProvider.sol';
-import {IRateOracle} from '../../interfaces/IRateOracle.sol';
 import {IERC20} from '../../dependencies/openzeppelin/contracts/IERC20.sol';
 import {DataTypes} from '../libraries/types/DataTypes.sol';
+import "hardhat/console.sol";
 
 /**
  * @title DefaultReserveInterestRateStrategy contract
@@ -54,14 +54,20 @@ contract DefaultReserveInterestRateStrategy is IReserveInterestRateStrategy {
   // Slope of the stable interest curve when utilization rate > OPTIMAL_UTILIZATION_RATE. Expressed in ray
   uint256 internal immutable _stableRateSlope2;
 
+  uint256 internal immutable _baseStableRateOffset;
+
+  uint256 internal immutable _stableRateExcessOffset;
+
   constructor(
     IPoolAddressesProvider provider,
     uint256 optimalUtilizationRate,
     uint256 baseVariableBorrowRate,
     uint256 variableRateSlope1,
     uint256 variableRateSlope2,
     uint256 stableRateSlope1,
-    uint256 stableRateSlope2
+    uint256 stableRateSlope2,
+    uint256 baseStableRateOffset,
+    uint256 stableRateExcessOffset
   ) {
     OPTIMAL_UTILIZATION_RATE = optimalUtilizationRate;
     EXCESS_UTILIZATION_RATE = WadRayMath.RAY - optimalUtilizationRate;
@@ -71,6 +77,8 @@ contract DefaultReserveInterestRateStrategy is IReserveInterestRateStrategy {
     _variableRateSlope2 = variableRateSlope2;
     _stableRateSlope1 = stableRateSlope1;
     _stableRateSlope2 = stableRateSlope2;
+    _baseStableRateOffset = baseStableRateOffset;
+    _stableRateExcessOffset = stableRateExcessOffset;
   }
 
   function getVariableRateSlope1() external view returns (uint256) {
@@ -89,6 +97,10 @@ contract DefaultReserveInterestRateStrategy is IReserveInterestRateStrategy {
     return _stableRateSlope2;
   }
 
+  function getBaseStableBorrowRate() public view returns(uint256) {
+    return _variableRateSlope1 + _baseStableRateOffset;
+  }
+
   /// @inheritdoc IReserveInterestRateStrategy
   function getBaseVariableBorrowRate() external view override returns (uint256) {
     return _baseVariableBorrowRate;
@@ -140,8 +152,7 @@ contract DefaultReserveInterestRateStrategy is IReserveInterestRateStrategy {
       ? 0
       : vars.totalDebt.rayDiv(vars.availableLiquidity + params.unbacked + vars.totalDebt);
 
-    vars.currentStableBorrowRate = IRateOracle(addressesProvider.getRateOracle())
-      .getMarketBorrowRate(params.reserve);
+    vars.currentStableBorrowRate = getBaseStableBorrowRate();
 
     if (vars.borrowUtilizationRate > OPTIMAL_UTILIZATION_RATE) {
       uint256 excessUtilizationRateRatio = (vars.borrowUtilizationRate - OPTIMAL_UTILIZATION_RATE)

helpers/contracts-deployments.ts

@@ -14,7 +14,6 @@ import {
   PoolAddressesProviderRegistryFactory,
   PoolConfiguratorFactory,
   PoolFactory,
-  RateOracleFactory,
   MintableDelegationERC20Factory,
   MintableERC20Factory,
   MockAggregatorFactory,
@@ -45,7 +44,6 @@ import {
   linkBytecode,
   insertContractAddressInDb,
 } from './contracts-helpers';
-import { RateOracleSetupHelperFactory } from '../types/RateOracleSetupHelperFactory';
 import { MintableDelegationERC20 } from '../types/MintableDelegationERC20';
 import { HardhatRuntimeEnvironment } from 'hardhat/types';
 import { PoolLibraryAddresses } from '../types/PoolFactory';
@@ -197,9 +195,6 @@ export const deployPool = async () => {
 export const deployPriceOracle = async () =>
   withSave(await new PriceOracleFactory(await getFirstSigner()).deploy(), eContractid.PriceOracle);
 
-export const deployRateOracle = async () =>
-  withSave(await new RateOracleFactory(await getFirstSigner()).deploy(), eContractid.RateOracle);
-
 export const deployMockAggregator = async (price: tStringTokenSmallUnits) =>
   withSave(
     await new MockAggregatorFactory(await getFirstSigner()).deploy(price),
@@ -241,7 +236,7 @@ export const deployMintableDelegationERC20 = async (
   );
 
 export const deployDefaultReserveInterestRateStrategy = async (
-  args: [tEthereumAddress, string, string, string, string, string, string]
+  args: [tEthereumAddress, string, string, string, string, string, string, string, string]
 ) =>
   withSave(
     await new DefaultReserveInterestRateStrategyFactory(await getFirstSigner()).deploy(...args),
@@ -353,12 +348,6 @@ export const deployAllMockTokens = async () => {
   return tokens;
 };
 
-export const deployRateOracleSetupHelper = async () =>
-  withSave(
-    await new RateOracleSetupHelperFactory(await getFirstSigner()).deploy(),
-    eContractid.RateOracleSetupHelper
-  );
-
 export const deployReservesSetupHelper = async () =>
   withSave(
     await new ReservesSetupHelperFactory(await getFirstSigner()).deploy(),

helpers/contracts-getters.ts

@@ -6,13 +6,11 @@ import {
   PoolAddressesProviderRegistryFactory,
   PoolConfiguratorFactory,
   PoolFactory,
-  RateOracleFactory,
   MintableERC20Factory,
   MockFlashLoanReceiverFactory,
   MockStableDebtTokenFactory,
   MockVariableDebtTokenFactory,
   PriceOracleFactory,
-  RateOracleSetupHelperFactory,
   StableDebtTokenFactory,
   VariableDebtTokenFactory,
   WETH9MockedFactory,
@@ -26,6 +24,8 @@ import {
   BridgeLogicFactory,
   ACLManagerFactory,
   EModeLogicFactory,
+  DefaultReserveInterestRateStrategy,
+  DefaultReserveInterestRateStrategyFactory,
 } from '../types';
 import { IERC20DetailedFactory } from '../types/IERC20DetailedFactory';
 import { getEthersSigners, MockTokenMap } from './contracts-helpers';
@@ -130,6 +130,15 @@ export const getVariableDebtToken = async (address?: tEthereumAddress) =>
     await getFirstSigner()
   );
 
+  export const getIRStrategy = async (address?: tEthereumAddress) =>
+  await DefaultReserveInterestRateStrategyFactory.connect(
+    address ||
+      (
+        await getDb().get(`${eContractid.DefaultReserveInterestRateStrategy}.${DRE.network.name}`).value()
+      ).address,
+    await getFirstSigner()
+  );
+
 export const getMintableERC20 = async (address: tEthereumAddress) =>
   await MintableERC20Factory.connect(
     address ||
@@ -172,12 +181,6 @@ export const getMockFlashLoanReceiver = async (address?: tEthereumAddress) =>
     await getFirstSigner()
   );
 
-export const getRateOracle = async (address?: tEthereumAddress) =>
-  await RateOracleFactory.connect(
-    address || (await getDb().get(`${eContractid.RateOracle}.${DRE.network.name}`).value()).address,
-    await getFirstSigner()
-  );
-
 export const getAllMockedTokens = async () => {
   const db = getDb();
   const tokens: MockTokenMap = await Object.keys(TokenContractId).reduce<Promise<MockTokenMap>>(
@@ -230,15 +233,6 @@ export const getPoolAddressesProviderRegistry = async (address?: tEthereumAddres
     await getFirstSigner()
   );
 
-export const getRateOracleSetupHelper = async (address?: tEthereumAddress) =>
-  await RateOracleSetupHelperFactory.connect(
-    address ||
-      (
-        await getDb().get(`${eContractid.RateOracleSetupHelper}.${DRE.network.name}`).value()
-      ).address,
-    await getFirstSigner()
-  );
-
 export const getReservesSetupHelper = async (address?: tEthereumAddress) =>
   await ReservesSetupHelperFactory.connect(
     address ||