feat: refactored the pool variable to immutable in atoken/debt tokens

contracts/interfaces/IInitializableAToken.sol

@@ -34,7 +34,6 @@ interface IInitializableAToken {
 
   /**
    * @notice Initializes the aToken
-   * @param pool The address of the pool where this aToken will be used
    * @param treasury The address of the Aave treasury, receiving the fees on this aToken
    * @param underlyingAsset The address of the underlying asset of this aToken (E.g. WETH for aWETH)
    * @param incentivesController The smart contract managing potential incentives distribution
@@ -44,7 +43,6 @@ interface IInitializableAToken {
    * @param params A set of encoded parameters for additional initialization
    */
   function initialize(
-    IPool pool,
     address treasury,
     address underlyingAsset,
     IAaveIncentivesController incentivesController,

contracts/interfaces/IInitializableDebtToken.sol

@@ -32,7 +32,6 @@ interface IInitializableDebtToken {
 
   /**
    * @notice Initializes the debt token.
-   * @param pool The address of the pool where this aToken will be used
    * @param underlyingAsset The address of the underlying asset of this aToken (E.g. WETH for aWETH)
    * @param incentivesController The smart contract managing potential incentives distribution
    * @param debtTokenDecimals The decimals of the debtToken, same as the underlying asset's
@@ -41,7 +40,6 @@ interface IInitializableDebtToken {
    * @param params A set of encoded parameters for additional initialization
    */
   function initialize(
-    IPool pool,
     address underlyingAsset,
     IAaveIncentivesController incentivesController,
     uint8 debtTokenDecimals,

contracts/mocks/upgradeability/MockAToken.sol

@@ -6,6 +6,8 @@ import {IPool} from '../../interfaces/IPool.sol';
 import {IAaveIncentivesController} from '../../interfaces/IAaveIncentivesController.sol';
 
 contract MockAToken is AToken {
+  constructor(IPool pool) AToken(pool) {}
+
   function getRevision() internal pure override returns (uint256) {
     return 0x2;
   }

contracts/mocks/upgradeability/MockStableDebtToken.sol

@@ -2,8 +2,11 @@
 pragma solidity 0.8.7;
 
 import {StableDebtToken} from '../../protocol/tokenization/StableDebtToken.sol';
+import {IPool} from '../../interfaces/IPool.sol';
 
 contract MockStableDebtToken is StableDebtToken {
+  constructor(IPool pool) StableDebtToken(pool) {}
+
   function getRevision() internal pure override returns (uint256) {
     return 0x3;
   }

contracts/mocks/upgradeability/MockVariableDebtToken.sol

@@ -2,8 +2,11 @@
 pragma solidity 0.8.7;
 
 import {VariableDebtToken} from '../../protocol/tokenization/VariableDebtToken.sol';
+import {IPool} from '../../interfaces/IPool.sol';
 
 contract MockVariableDebtToken is VariableDebtToken {
+  constructor(IPool pool) VariableDebtToken(pool) {}
+
   function getRevision() internal pure override returns (uint256) {
     return 0x3;
   }

contracts/protocol/libraries/logic/ConfiguratorLogic.sol

@@ -53,7 +53,6 @@ library ConfiguratorLogic {
       input.aTokenImpl,
       abi.encodeWithSelector(
         IInitializableAToken.initialize.selector,
-        pool,
         input.treasury,
         input.underlyingAsset,
         IAaveIncentivesController(input.incentivesController),
@@ -68,7 +67,6 @@ library ConfiguratorLogic {
       input.stableDebtTokenImpl,
       abi.encodeWithSelector(
         IInitializableDebtToken.initialize.selector,
-        pool,
         input.underlyingAsset,
         IAaveIncentivesController(input.incentivesController),
         input.underlyingAssetDecimals,
@@ -82,7 +80,6 @@ library ConfiguratorLogic {
       input.variableDebtTokenImpl,
       abi.encodeWithSelector(
         IInitializableDebtToken.initialize.selector,
-        pool,
         input.underlyingAsset,
         IAaveIncentivesController(input.incentivesController),
         input.underlyingAssetDecimals,
@@ -126,11 +123,10 @@ library ConfiguratorLogic {
   {
     DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);
 
-    (, , , uint256 decimals, ,) = cachedPool.getConfiguration(input.asset).getParams();
+    (, , , uint256 decimals, , ) = cachedPool.getConfiguration(input.asset).getParams();
 
     bytes memory encodedCall = abi.encodeWithSelector(
       IInitializableAToken.initialize.selector,
-      cachedPool,
       input.treasury,
       input.asset,
       input.incentivesController,
@@ -151,11 +147,10 @@ library ConfiguratorLogic {
   ) public {
     DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);
 
-    (, , , uint256 decimals, ,) = cachedPool.getConfiguration(input.asset).getParams();
+    (, , , uint256 decimals, , ) = cachedPool.getConfiguration(input.asset).getParams();
 
     bytes memory encodedCall = abi.encodeWithSelector(
       IInitializableDebtToken.initialize.selector,
-      cachedPool,
       input.asset,
       input.incentivesController,
       decimals,
@@ -183,11 +178,10 @@ library ConfiguratorLogic {
   ) public {
     DataTypes.ReserveData memory reserveData = cachedPool.getReserveData(input.asset);
 
-    (, , , uint256 decimals, ,) = cachedPool.getConfiguration(input.asset).getParams();
+    (, , , uint256 decimals, , ) = cachedPool.getConfiguration(input.asset).getParams();
 
     bytes memory encodedCall = abi.encodeWithSelector(
       IInitializableDebtToken.initialize.selector,
-      cachedPool,
       input.asset,
       input.incentivesController,
       decimals,

contracts/protocol/tokenization/AToken.sol

@@ -40,7 +40,7 @@ contract AToken is
 
   bytes32 public DOMAIN_SEPARATOR;
 
-  IPool internal _pool;
+  IPool internal immutable _pool;
   address internal _treasury;
   address internal _underlyingAsset;
 
@@ -54,9 +54,12 @@ contract AToken is
     return ATOKEN_REVISION;
   }
 
+  constructor(IPool pool) {
+    _pool = pool;
+  }
+
   /// @inheritdoc IInitializableAToken
   function initialize(
-    IPool pool,
     address treasury,
     address underlyingAsset,
     IAaveIncentivesController incentivesController,
@@ -86,14 +89,13 @@ contract AToken is
     _setSymbol(aTokenSymbol);
     _setDecimals(aTokenDecimals);
 
-    _pool = pool;
     _treasury = treasury;
     _underlyingAsset = underlyingAsset;
     _incentivesController = incentivesController;
 
     emit Initialized(
       underlyingAsset,
-      address(pool),
+      address(_pool),
       treasury,
       address(incentivesController),
       aTokenDecimals,
@@ -309,17 +311,16 @@ contract AToken is
     bool validate
   ) internal {
     address underlyingAsset = _underlyingAsset;
-    IPool pool = _pool;
 
-    uint256 index = pool.getReserveNormalizedIncome(underlyingAsset);
+    uint256 index = _pool.getReserveNormalizedIncome(underlyingAsset);
 
     uint256 fromBalanceBefore = super.balanceOf(from).rayMul(index);
     uint256 toBalanceBefore = super.balanceOf(to).rayMul(index);
 
     super._transfer(from, to, Helpers.castUint128(amount.rayDiv(index)));
 
     if (validate) {
-      pool.finalizeTransfer(underlyingAsset, from, to, amount, fromBalanceBefore, toBalanceBefore);
+      _pool.finalizeTransfer(underlyingAsset, from, to, amount, fromBalanceBefore, toBalanceBefore);
     }
 
     emit BalanceTransfer(from, to, amount, index);

contracts/protocol/tokenization/DelegationAwareAToken.sol

@@ -14,6 +14,8 @@ import {AToken} from './AToken.sol';
  * @dev The underlying asset needs to be compatible with the COMP delegation interface
  */
 contract DelegationAwareAToken is AToken {
+  constructor(IPool pool) AToken(pool) {}
+
   modifier onlyPoolAdmin() {
     IACLManager aclManager = IACLManager(IPool(_pool).getAddressesProvider().getACLManager());
     require(aclManager.isPoolAdmin(msg.sender), Errors.CALLER_NOT_POOL_ADMIN);

contracts/protocol/tokenization/StableDebtToken.sol

@@ -29,12 +29,15 @@ contract StableDebtToken is IStableDebtToken, DebtTokenBase {
   mapping(address => uint40) internal _timestamps;
   uint40 internal _totalSupplyTimestamp;
 
-  IPool internal _pool;
+  IPool internal immutable _pool;
   address internal _underlyingAsset;
 
+  constructor(IPool pool) {
+    _pool = pool;
+  }
+
   /// @inheritdoc IInitializableDebtToken
   function initialize(
-    IPool pool,
     address underlyingAsset,
     IAaveIncentivesController incentivesController,
     uint8 debtTokenDecimals,
@@ -53,7 +56,6 @@ contract StableDebtToken is IStableDebtToken, DebtTokenBase {
     _setSymbol(debtTokenSymbol);
     _setDecimals(debtTokenDecimals);
 
-    _pool = pool;
     _underlyingAsset = underlyingAsset;
     _incentivesController = incentivesController;
 
@@ -69,7 +71,7 @@ contract StableDebtToken is IStableDebtToken, DebtTokenBase {
 
     emit Initialized(
       underlyingAsset,
-      address(pool),
+      address(_pool),
       address(incentivesController),
       debtTokenDecimals,
       debtTokenName,

contracts/protocol/tokenization/VariableDebtToken.sol

@@ -24,12 +24,15 @@ contract VariableDebtToken is DebtTokenBase, IVariableDebtToken {
 
   uint256 public constant DEBT_TOKEN_REVISION = 0x2;
 
-  IPool internal _pool;
+  IPool internal immutable _pool;
   address internal _underlyingAsset;
 
+  constructor(IPool pool) {
+    _pool = pool;
+  }
+
   /// @inheritdoc IInitializableDebtToken
   function initialize(
-    IPool pool,
     address underlyingAsset,
     IAaveIncentivesController incentivesController,
     uint8 debtTokenDecimals,
@@ -48,7 +51,6 @@ contract VariableDebtToken is DebtTokenBase, IVariableDebtToken {
     _setSymbol(debtTokenSymbol);
     _setDecimals(debtTokenDecimals);
 
-    _pool = pool;
     _underlyingAsset = underlyingAsset;
     _incentivesController = incentivesController;
 
@@ -64,7 +66,7 @@ contract VariableDebtToken is DebtTokenBase, IVariableDebtToken {
 
     emit Initialized(
       underlyingAsset,
-      address(pool),
+      address(_pool),
       address(incentivesController),
       debtTokenDecimals,
       debtTokenName,

helpers/contracts-deployments.ts

@@ -241,15 +241,15 @@ export const deployDefaultReserveInterestRateStrategy = async (
     eContractid.DefaultReserveInterestRateStrategy
   );
 
-export const deployGenericStableDebtToken = async () =>
+export const deployGenericStableDebtToken = async (poolAddress: tEthereumAddress) =>
   withSave(
-    await new StableDebtTokenFactory(await getFirstSigner()).deploy(),
+    await new StableDebtTokenFactory(await getFirstSigner()).deploy(poolAddress),
     eContractid.StableDebtToken
   );
 
-export const deployGenericVariableDebtToken = async () =>
+export const deployGenericVariableDebtToken = async (poolAddress: tEthereumAddress) =>
   withSave(
-    await new VariableDebtTokenFactory(await getFirstSigner()).deploy(),
+    await new VariableDebtTokenFactory(await getFirstSigner()).deploy(poolAddress),
     eContractid.VariableDebtToken
   );
 
@@ -262,12 +262,11 @@ export const deployGenericAToken = async ([
   symbol,
 ]: [tEthereumAddress, tEthereumAddress, tEthereumAddress, tEthereumAddress, string, string]) => {
   const instance = await withSave(
-    await new ATokenFactory(await getFirstSigner()).deploy(),
+    await new ATokenFactory(await getFirstSigner()).deploy(poolAddress),
     eContractid.AToken
   );
 
   await instance.initialize(
-    poolAddress,
     treasuryAddress,
     underlyingAssetAddress,
     incentivesController,
@@ -280,24 +279,23 @@ export const deployGenericAToken = async ([
   return instance;
 };
 
-export const deployGenericATokenImpl = async () =>
-  withSave(await new ATokenFactory(await getFirstSigner()).deploy(), eContractid.AToken);
+export const deployGenericATokenImpl = async (poolAddress: tEthereumAddress) =>
+  withSave(await new ATokenFactory(await getFirstSigner()).deploy(poolAddress), eContractid.AToken);
 
 export const deployDelegationAwareAToken = async ([
-  pool,
+  poolAddress,
   underlyingAssetAddress,
   treasuryAddress,
   incentivesController,
   name,
   symbol,
 ]: [tEthereumAddress, tEthereumAddress, tEthereumAddress, tEthereumAddress, string, string]) => {
   const instance = await withSave(
-    await new DelegationAwareATokenFactory(await getFirstSigner()).deploy(),
+    await new DelegationAwareATokenFactory(await getFirstSigner()).deploy(poolAddress),
     eContractid.DelegationAwareAToken
   );
 
   await instance.initialize(
-    pool,
     treasuryAddress,
     underlyingAssetAddress,
     incentivesController,
@@ -310,9 +308,9 @@ export const deployDelegationAwareAToken = async ([
   return instance;
 };
 
-export const deployDelegationAwareATokenImpl = async () =>
+export const deployDelegationAwareATokenImpl = async (poolAddress: tEthereumAddress) =>
   withSave(
-    await new DelegationAwareATokenFactory(await getFirstSigner()).deploy(),
+    await new DelegationAwareATokenFactory(await getFirstSigner()).deploy(poolAddress),
     eContractid.DelegationAwareAToken
   );
 
@@ -366,11 +364,11 @@ export const deployMockStableDebtToken = async (
   args: [tEthereumAddress, tEthereumAddress, tEthereumAddress, string, string, string]
 ) => {
   const instance = await withSave(
-    await new MockStableDebtTokenFactory(await getFirstSigner()).deploy(),
+    await new MockStableDebtTokenFactory(await getFirstSigner()).deploy(args[0]),
     eContractid.MockStableDebtToken
   );
 
-  await instance.initialize(args[0], args[1], args[2], '18', args[3], args[4], args[5]);
+  await instance.initialize(args[1], args[2], '18', args[3], args[4], args[5]);
 
   return instance;
 };
@@ -382,11 +380,11 @@ export const deployMockVariableDebtToken = async (
   args: [tEthereumAddress, tEthereumAddress, tEthereumAddress, string, string, string]
 ) => {
   const instance = await withSave(
-    await new MockVariableDebtTokenFactory(await getFirstSigner()).deploy(),
+    await new MockVariableDebtTokenFactory(await getFirstSigner()).deploy(args[0]),
     eContractid.MockVariableDebtToken
   );
 
-  await instance.initialize(args[0], args[1], args[2], '18', args[3], args[4], args[5]);
+  await instance.initialize(args[1], args[2], '18', args[3], args[4], args[5]);
 
   return instance;
 };
@@ -403,11 +401,11 @@ export const deployMockAToken = async (
   ]
 ) => {
   const instance = await withSave(
-    await new MockATokenFactory(await getFirstSigner()).deploy(),
+    await new MockATokenFactory(await getFirstSigner()).deploy(args[0]),
     eContractid.MockAToken
   );
 
-  await instance.initialize(args[0], args[2], args[1], args[3], '18', args[4], args[5], args[6]);
+  await instance.initialize(args[2], args[1], args[3], '18', args[4], args[5], args[6]);
 
   return instance;
 };