fix: use bps instead of ray

src/contracts/misc/GhoAaveSteward.sol

@@ -26,6 +26,12 @@ contract GhoAaveSteward is RiskCouncilControlled, IGhoAaveSteward {
   using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
   using Address for address;
 
+  /// @inheritdoc IGhoAaveSteward
+  uint256 public constant GHO_BORROW_RATE_CHANGE_MAX = 0.0500e27; // 5.00%
+
+  /// @inheritdoc IGhoAaveSteward
+  uint256 public constant GHO_BORROW_RATE_MAX = 0.2500e27; // 25.00%
+
   /// @inheritdoc IGhoAaveSteward
   address public immutable CONFIG_ENGINE;
 
@@ -88,6 +94,7 @@ contract GhoAaveSteward is RiskCouncilControlled, IGhoAaveSteward {
 
   /// @inheritdoc IGhoAaveSteward
   function updateGhoBorrowRate(
+    /* TODO: Add all 4 parameters back */
     uint256 baseVariableBorrowRate
   ) external onlyRiskCouncil notTimelocked(_ghoTimelocks.ghoBorrowCapLastUpdate) {
     _validateRatesUpdate(baseVariableBorrowRate);
@@ -185,15 +192,14 @@ contract GhoAaveSteward is RiskCouncilControlled, IGhoAaveSteward {
 
   function _validateRatesUpdate(uint256 baseVariableBorrowRate) internal view {
     (, uint256 currentBaseVariableBorrowRate, , ) = _getInterestRatesForAsset(GHO_TOKEN);
-
     require(
       _updateWithinAllowedRange(
         currentBaseVariableBorrowRate,
         baseVariableBorrowRate,
         0.05e4,
         false
       ),
-      'INVALID_BASE_VARIABLE_BORROW_RATE_UPDATE'
+      'INVALID_BORROW_RATE_UPDATE'
     );
   }
 

src/contracts/misc/interfaces/IGhoAaveSteward.sol

@@ -70,6 +70,18 @@ interface IGhoAaveSteward {
    */
   function updateGhoSupplyCap(uint256 newSupplyCap) external;
 
+  /**
+   * @notice Returns the maximum increase/decrease for GHO borrow rate updates.
+   * @return The maximum increase change for borrow rate updates in ray (e.g. 0.010e27 results in 1.00%)
+   */
+  function GHO_BORROW_RATE_CHANGE_MAX() external view returns (uint256);
+
+  /**
+   * @notice Returns maximum value that can be assigned to GHO borrow rate.
+   * @return The maximum value that can be assigned to GHO borrow rate in ray (e.g. 0.01e27 results in 1.0%)
+   */
+  function GHO_BORROW_RATE_MAX() external view returns (uint256);
+
   /**
    * @notice The address of the config engine used to perform the borrow rate update via delegatecall
    */

src/test/TestGhoAaveSteward.t.sol

@@ -3,22 +3,35 @@ pragma solidity ^0.8.0;
 
 import './TestGhoBase.t.sol';
 import {IGhoAaveSteward} from '../contracts/misc/interfaces/IGhoAaveSteward.sol';
+import {IDefaultInterestRateStrategyV2} from '../contracts/misc/deps/Dependencies.sol';
 
 contract TestGhoAaveSteward is TestGhoBase {
   using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
 
   function setUp() public {
     // Deploy Gho Aave Steward
-    MockConfigEngine engine = new MockConfigEngine();
+    MockConfigEngine engine = new MockConfigEngine(address(CONFIGURATOR), address(PROVIDER));
     GHO_AAVE_STEWARD = new GhoAaveSteward(
       address(PROVIDER),
-      address(AaveV3Ethereum.AAVE_PROTOCOL_DATA_PROVIDER),
+      address(MOCK_POOL_DATA_PROVIDER),
       address(engine),
       address(GHO_TOKEN),
       address(FIXED_RATE_STRATEGY_FACTORY),
       RISK_COUNCIL
     );
 
+    MockConfigEngine.RateStrategyUpdate[] memory update = new MockConfigEngine.RateStrategyUpdate[](
+      1
+    );
+    update[0].asset = address(GHO_TOKEN);
+    update[0].params = MockConfigEngine.InterestRateInputData({
+      optimalUsageRatio: 1_00,
+      baseVariableBorrowRate: 0.25e4,
+      variableRateSlope1: 0,
+      variableRateSlope2: 0
+    });
+    engine.updateRateStrategies(update);
+
     /// @dev Since block.timestamp starts at 0 this is a necessary condition (block.timestamp > `MINIMUM_DELAY`) for the timelocked contract methods to work.
     vm.warp(GHO_AAVE_STEWARD.MINIMUM_DELAY() + 1);
   }
@@ -27,10 +40,7 @@ contract TestGhoAaveSteward is TestGhoBase {
     assertEq(GHO_AAVE_STEWARD.MINIMUM_DELAY(), MINIMUM_DELAY_V2);
 
     assertEq(GHO_AAVE_STEWARD.POOL_ADDRESSES_PROVIDER(), address(PROVIDER));
-    assertEq(
-      GHO_AAVE_STEWARD.POOL_DATA_PROVIDER(),
-      address(AaveV3Ethereum.AAVE_PROTOCOL_DATA_PROVIDER)
-    );
+    assertEq(GHO_AAVE_STEWARD.POOL_DATA_PROVIDER(), address(MOCK_POOL_DATA_PROVIDER));
     assertEq(GHO_AAVE_STEWARD.GHO_TOKEN(), address(GHO_TOKEN));
     assertEq(GHO_AAVE_STEWARD.FIXED_RATE_STRATEGY_FACTORY(), address(FIXED_RATE_STRATEGY_FACTORY));
     assertEq(GHO_AAVE_STEWARD.RISK_COUNCIL(), RISK_COUNCIL);
@@ -257,6 +267,41 @@ contract TestGhoAaveSteward is TestGhoBase {
     GHO_AAVE_STEWARD.updateGhoSupplyCap(oldSupplyCap * 2 + 1);
   }
 
+  function testUpdateGhoBorrowRate() public {
+    vm.prank(RISK_COUNCIL);
+    GHO_AAVE_STEWARD.updateGhoBorrowRate(0.26e4);
+    assertEq(_getGhoBorrowRate(), 0.26e4);
+  }
+
+  function testUpdateGhoBorrowRateUpwards() public {
+    uint256 oldBorrowRate = _getGhoBorrowRate();
+    uint256 newBorrowRate = oldBorrowRate + 1;
+    vm.prank(RISK_COUNCIL);
+    GHO_AAVE_STEWARD.updateGhoBorrowRate(newBorrowRate);
+    uint256 currentBorrowRate = _getGhoBorrowRate();
+    assertEq(currentBorrowRate, newBorrowRate);
+  }
+
+  function testRevertUpdateGhoBorrowRateIfMaxExceededDownwards() public {
+    vm.startPrank(RISK_COUNCIL);
+
+    // set a high borrow rate
+    GHO_AAVE_STEWARD.updateGhoBorrowRate(
+      _getGhoBorrowRate() + GHO_AAVE_STEWARD.GHO_BORROW_RATE_CHANGE_MAX() / 1e23
+    );
+    vm.warp(block.timestamp + GHO_AAVE_STEWARD.MINIMUM_DELAY() + 1);
+
+    uint256 oldBorrowRate = _getGhoBorrowRate();
+    uint256 newBorrowRate = oldBorrowRate -
+      GHO_AAVE_STEWARD.GHO_BORROW_RATE_CHANGE_MAX() /
+      1e23 -
+      1;
+    vm.expectRevert('INVALID_BORROW_RATE_UPDATE');
+    GHO_AAVE_STEWARD.updateGhoBorrowRate(newBorrowRate);
+
+    vm.stopPrank();
+  }
+
   function _setGhoBorrowCapViaConfigurator(uint256 newBorrowCap) internal {
     CONFIGURATOR.setBorrowCap(address(GHO_TOKEN), newBorrowCap);
   }
@@ -278,4 +323,35 @@ contract TestGhoAaveSteward is TestGhoBase {
     );
     return configuration.getSupplyCap();
   }
+
+  function _setGhoBorrowRateViaConfigurator(
+    uint256 newBorrowRate
+  ) internal returns (GhoInterestRateStrategy, uint256) {
+    GhoInterestRateStrategy newRateStrategy = new GhoInterestRateStrategy(
+      address(PROVIDER),
+      newBorrowRate
+    );
+    CONFIGURATOR.setReserveInterestRateStrategyAddress(
+      address(GHO_TOKEN),
+      address(newRateStrategy)
+    );
+    address currentInterestRateStrategy = POOL.getReserveInterestRateStrategyAddress(
+      address(GHO_TOKEN)
+    );
+    uint256 currentBorrowRate = GhoInterestRateStrategy(currentInterestRateStrategy)
+      .getBaseVariableBorrowRate();
+    assertEq(currentInterestRateStrategy, address(newRateStrategy));
+    assertEq(currentBorrowRate, newBorrowRate);
+    return (newRateStrategy, newBorrowRate);
+  }
+
+  function _getGhoBorrowRate() internal view returns (uint256) {
+    address currentInterestRateStrategy = POOL.getReserveInterestRateStrategyAddress(
+      address(GHO_TOKEN)
+    );
+    return
+      IDefaultInterestRateStrategyV2(currentInterestRateStrategy).getBaseVariableBorrowRate(
+        address(GHO_TOKEN)
+      ) / 1e23; // Convert to bps
+  }
 }

src/test/TestGhoBase.t.sol

@@ -30,6 +30,7 @@ import {PriceOracle} from '@aave/core-v3/contracts/mocks/oracle/PriceOracle.sol'
 import {TestnetERC20} from '@aave/periphery-v3/contracts/mocks/testnet-helpers/TestnetERC20.sol';
 import {WETH9Mock} from '@aave/periphery-v3/contracts/mocks/WETH9Mock.sol';
 import {MockConfigEngine} from './mocks/MockConfigEngine.sol';
+import {MockPoolDataProvider} from './mocks/MockPoolDataProvider.sol';
 
 // interfaces
 import {IAaveIncentivesController} from '@aave/core-v3/contracts/interfaces/IAaveIncentivesController.sol';
@@ -143,6 +144,7 @@ contract TestGhoBase is Test, Constants, Events {
   GhoCcipSteward GHO_CCIP_STEWARD;
   GhoGsmSteward GHO_GSM_STEWARD;
   GhoBucketCapacitySteward GHO_BUCKET_CAPACITY_STEWARD;
+  MockPoolDataProvider MOCK_POOL_DATA_PROVIDER;
 
   FixedRateStrategyFactory FIXED_RATE_STRATEGY_FACTORY;
   GsmFeeStrategyFactory GSM_FEE_STRATEGY_FACTORY;
@@ -161,6 +163,7 @@ contract TestGhoBase is Test, Constants, Events {
     bytes memory empty;
     ACL_MANAGER = new MockAclManager();
     PROVIDER = new MockAddressesProvider(address(ACL_MANAGER));
+    MOCK_POOL_DATA_PROVIDER = new MockPoolDataProvider(address(PROVIDER));
     POOL = new MockPool(IPoolAddressesProvider(address(PROVIDER)));
     CONFIGURATOR = new MockConfigurator(IPool(POOL));
     PRICE_ORACLE = new PriceOracle();

src/test/mocks/MockConfigEngine.sol

@@ -1,8 +1,19 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.10;
 
+import {MockConfigurator} from './MockConfigurator.sol';
+import {GhoInterestRateStrategy} from 'src/contracts/facilitators/aave/interestStrategy/GhoInterestRateStrategy.sol';
+import {DefaultReserveInterestRateStrategyV2} from '../../contracts/misc/deps/Dependencies.sol';
+import {IDefaultInterestRateStrategyV2} from '../../contracts/misc/deps/Dependencies.sol';
+
 contract MockConfigEngine {
-  constructor() {}
+  address public immutable CONFIGURATOR;
+  address public immutable PROVIDER;
+
+  constructor(address configurator, address provider) {
+    CONFIGURATOR = configurator;
+    PROVIDER = provider;
+  }
 
   struct InterestRateInputData {
     uint256 optimalUsageRatio;
@@ -16,5 +27,29 @@ contract MockConfigEngine {
     InterestRateInputData params;
   }
 
-  function updateRateStrategies(RateStrategyUpdate[] calldata updates) external {}
+  function updateRateStrategies(RateStrategyUpdate[] calldata updates) external {
+    /*
+    GhoInterestRateStrategy newRateStrategy = new GhoInterestRateStrategy(
+      address(PROVIDER),
+      updates[0].params.baseVariableBorrowRate
+    );*/
+    DefaultReserveInterestRateStrategyV2 newRateStrategy = new DefaultReserveInterestRateStrategyV2(
+      address(PROVIDER)
+    );
+
+    MockConfigurator(CONFIGURATOR).setReserveInterestRateStrategyAddress(
+      address(updates[0].asset),
+      address(newRateStrategy)
+    );
+
+    MockConfigurator(CONFIGURATOR).setReserveInterestRateParams(
+      address(updates[0].asset),
+      IDefaultInterestRateStrategyV2.InterestRateData({
+        optimalUsageRatio: uint16(updates[0].params.optimalUsageRatio),
+        baseVariableBorrowRate: uint32(updates[0].params.baseVariableBorrowRate),
+        variableRateSlope1: uint32(updates[0].params.variableRateSlope1),
+        variableRateSlope2: uint32(updates[0].params.variableRateSlope2)
+      })
+    );
+  }
 }

src/test/mocks/MockConfigurator.sol

@@ -4,6 +4,8 @@ pragma solidity ^0.8.0;
 import {IPool} from '@aave/core-v3/contracts/interfaces/IPool.sol';
 import {DataTypes} from '@aave/core-v3/contracts/protocol/libraries/types/DataTypes.sol';
 import {ReserveConfiguration} from '@aave/core-v3/contracts/protocol/libraries/configuration/ReserveConfiguration.sol';
+import {DefaultReserveInterestRateStrategyV2} from '../../contracts/misc/deps/Dependencies.sol';
+import {IDefaultInterestRateStrategyV2} from '../../contracts/misc/deps/Dependencies.sol';
 
 contract MockConfigurator {
   using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
@@ -39,6 +41,18 @@ contract MockConfigurator {
     emit ReserveInterestRateStrategyChanged(asset, oldRateStrategyAddress, newRateStrategyAddress);
   }
 
+  function setReserveInterestRateParams(
+    address asset,
+    IDefaultInterestRateStrategyV2.InterestRateData calldata rateParams
+  ) external {
+    DataTypes.ReserveData memory reserve = _pool.getReserveData(asset);
+    address rateStrategyAddress = reserve.interestRateStrategyAddress;
+    DefaultReserveInterestRateStrategyV2(rateStrategyAddress).setInterestRateParams(
+      asset,
+      rateParams
+    );
+  }
+
   function setBorrowCap(address asset, uint256 newBorrowCap) external {
     DataTypes.ReserveConfigurationMap memory currentConfig = _pool.getConfiguration(asset);
     uint256 oldBorrowCap = currentConfig.getBorrowCap();