feat: add validation that payload has no storage vars

foundry.toml

@@ -5,10 +5,12 @@ script = 'scripts'
 out = 'out'
 libs = ['lib']
 remappings = []
-fs_permissions = [{ access = "read-write", path = "./reports" }]
+fs_permissions = [{ access = "read-write", path = "./reports" }, { access = "read", path = "./out" }]
 ffi = true
 evm_version = 'cancun'
 decode_external_storage = true
+allow_internal_expect_revert = true
+extra_output = ["storageLayout"]
 
 [profile.zksync]
 src = 'zksync/src'

src/ProtocolV2TestBase.sol

@@ -7,6 +7,7 @@ import {ReserveConfiguration} from 'aave-v3-origin/contracts/protocol/libraries/
 import {IERC20} from 'openzeppelin-contracts/contracts/token/ERC20/IERC20.sol';
 import {IERC20Metadata} from 'openzeppelin-contracts/contracts/token/ERC20/extensions/IERC20Metadata.sol';
 import {SafeERC20} from 'openzeppelin-contracts/contracts/token/ERC20/utils/SafeERC20.sol';
+import {Strings} from 'openzeppelin-contracts/contracts/utils/Strings.sol';
 import {AaveV2EthereumAMM} from 'aave-address-book/AaveV2EthereumAMM.sol';
 import {AaveV2EthereumAssets} from 'aave-address-book/AaveV2Ethereum.sol';
 import {DiffUtils} from './DiffUtils.sol';
@@ -85,6 +86,10 @@ contract ProtocolV2TestBase is CommonTestBase, SeatbeltUtils, DiffUtils {
 
     string memory afterString = string(abi.encodePacked(reportName, '_after'));
     ReserveConfig[] memory configAfter = createConfigurationSnapshot(afterString, pool);
+
+    // as executor does delegateCall to the payload, the payload should have no storage variable
+    _validateNoPayloadStorageSlots(payload);
+
     vm.writeJson(
       vm.serializeString('root', 'raw', rawDiff), // output
       string(abi.encodePacked('./reports/', afterString, '.json'))
@@ -993,6 +998,41 @@ contract ProtocolV2TestBase is CommonTestBase, SeatbeltUtils, DiffUtils {
     );
   }
 
+  /**
+   * @dev Validates that a payload contract declares no state variables by inspecting the
+   *      compiler-generated storage layout from the build artifact.
+   *
+   *      If the artifact cannot be resolved (e.g. the contract was not compiled locally),
+   *      you can skip this test manually by overriding this virtual method in your test
+   *
+   *      Requires foundry.toml to have:
+   *        extra_output = ["storageLayout"]
+   *        fs_permissions includes { access = "read", path = "./out" }
+   */
+  function _validateNoPayloadStorageSlots(address payload) internal view virtual {
+    string memory artifactPath = vm.getArtifactPathByDeployedCode(payload.code);
+    string memory artifact = vm.readFile(artifactPath);
+
+    // vm.parseJson ABI-encodes the JSON value at the given key.
+    // A dynamic array is encoded as [uint256 offset][uint256 length][elements...], so
+    // decoding the first two words as (uint256, uint256) yields (offset, arrayLength).
+    bytes memory storageEncoded = vm.parseJson(artifact, '.storageLayout.storage');
+    (, uint256 storageLength) = abi.decode(storageEncoded, (uint256, uint256));
+
+    require(
+      storageLength == 0,
+      string(
+        abi.encodePacked(
+          'PAYLOAD_MUST_NOT_HAVE_STORAGE_VARIABLES: ',
+          artifactPath,
+          ' declares ',
+          Strings.toString(storageLength),
+          ' storage slot(s)'
+        )
+      )
+    );
+  }
+
   function _isInUint256Array(
     uint256[] memory haystack,
     uint256 needle

src/ProtocolV3TestBase.sol

@@ -96,6 +96,9 @@ contract ProtocolV3TestBase is RawProtocolV3TestBase, SeatbeltUtils, CommonTestB
 
     ReserveConfig[] memory configAfter = createConfigurationSnapshot(afterString, pool);
 
+    // as executor does delegateCall to the payload, the payload should have no storage variable
+    _validateNoPayloadStorageSlots(payload);
+
     {
       string memory rawDiff = vm.getStateDiffJson();
       vm.writeJson(rawDiff, string(abi.encodePacked('./reports/', afterString, '.json')), '$.raw');
@@ -729,4 +732,39 @@ contract ProtocolV3TestBase is RawProtocolV3TestBase, SeatbeltUtils, CommonTestB
 
     vm.stopPrank();
   }
+
+  /**
+   * @dev Validates that a payload contract declares no state variables by inspecting the
+   *      compiler-generated storage layout from the build artifact.
+   *
+   *      If the artifact cannot be resolved (e.g. the contract was not compiled locally),
+   *      you can skip this test manually by overriding this virtual method in your test
+   *
+   *      Requires foundry.toml to have:
+   *        extra_output = ["storageLayout"]
+   *        fs_permissions includes { access = "read", path = "./out" }
+   */
+  function _validateNoPayloadStorageSlots(address payload) internal view virtual {
+    string memory artifactPath = vm.getArtifactPathByDeployedCode(payload.code);
+    string memory artifact = vm.readFile(artifactPath);
+
+    // vm.parseJson ABI-encodes the JSON value at the given key.
+    // A dynamic array is encoded as [uint256 offset][uint256 length][elements...], so
+    // decoding the first two words as (uint256, uint256) yields (offset, arrayLength).
+    bytes memory storageEncoded = vm.parseJson(artifact, '.storageLayout.storage');
+    (, uint256 storageLength) = abi.decode(storageEncoded, (uint256, uint256));
+
+    require(
+      storageLength == 0,
+      string(
+        abi.encodePacked(
+          'PAYLOAD_MUST_NOT_HAVE_STORAGE_VARIABLES: ',
+          artifactPath,
+          ' declares ',
+          Strings.toString(storageLength),
+          ' storage slot(s)'
+        )
+      )
+    );
+  }
 }

tests/ProtocolV2TestBase.t.sol

@@ -7,6 +7,7 @@ import {AaveV2Ethereum, AaveV2EthereumAssets} from 'aave-address-book/AaveV2Ethe
 import {AaveV2EthereumAMM} from 'aave-address-book/AaveV2EthereumAMM.sol';
 import {IERC20} from 'openzeppelin-contracts/contracts/token/ERC20/IERC20.sol';
 import {PayloadWithEmit} from './mocks/PayloadWithEmit.sol';
+import {PayloadWithStorage} from './mocks/PayloadWithStorage.sol';
 
 contract ProtocolV2TestBaseTest is ProtocolV2TestBase {
   function setUp() public {
@@ -40,3 +41,24 @@ contract ProtocolV2TestE2ETestAsset is ProtocolV2TestBase {
     defaultTest('AMMTEST', AaveV2EthereumAMM.POOL, address(new PayloadWithEmit()), false, false);
   }
 }
+
+contract ProtocolV2TestStorageValidation is ProtocolV2TestBase {
+  function test_noStorageSlots_passes() public {
+    // PayloadWithEmit has no state variables — should pass silently.
+    _validateNoPayloadStorageSlots(address(new PayloadWithEmit()));
+  }
+
+  function test_withStorageSlots_reverts() public {
+    address payload = address(new PayloadWithStorage());
+    // PayloadWithStorage declares `uint256 internal _randomStorageVariable` — must be rejected.
+    vm.expectRevert();
+    _validateNoPayloadStorageSlots(payload);
+  }
+
+  function test_unknownArtifact_logsWarning() public {
+    // makeAddr produces an address with no deployed code; getArtifactPathByDeployedCode
+    // cannot resolve it, so the function vm.getArtifactPathByDeployedCode reverts
+    vm.expectRevert();
+    _validateNoPayloadStorageSlots(makeAddr('unknownPayload'));
+  }
+}

tests/ProtocolV3TestBase.t.sol

@@ -13,6 +13,7 @@ import {AaveV3MegaEth} from 'aave-address-book/AaveV3MegaEth.sol';
 import {AaveV3Mantle} from 'aave-address-book/AaveV3Mantle.sol';
 import {AaveV3Fantom} from 'aave-address-book/AaveV3Fantom.sol';
 import {PayloadWithEmit} from './mocks/PayloadWithEmit.sol';
+import {PayloadWithStorage} from './mocks/PayloadWithStorage.sol';
 
 contract ProtocolV3TestBaseTest is ProtocolV3TestBase {
   function setUp() public {
@@ -179,4 +180,28 @@ contract ProtocolV3TestMantleSnapshot is ProtocolV3TestBase {
       false
     );
   }
+
+  // overriding the storage slot check as payload artifacts does not exists
+  function _validateNoPayloadStorageSlots(address payload) internal view override {}
+}
+
+contract ProtocolV3TestStorageValidation is ProtocolV3TestBase {
+  function test_noStorageSlots_passes() public {
+    // PayloadWithEmit has no state variables — should pass silently.
+    _validateNoPayloadStorageSlots(address(new PayloadWithEmit()));
+  }
+
+  function test_withStorageSlots_reverts() public {
+    address payload = address(new PayloadWithStorage());
+    // PayloadWithStorage declares `uint256 internal _randomStorageVariable` — must be rejected.
+    vm.expectRevert();
+    _validateNoPayloadStorageSlots(payload);
+  }
+
+  function test_unknownArtifact_logsWarning() public {
+    // makeAddr produces an address with no deployed code; getArtifactPathByDeployedCode
+    // cannot resolve it, so the function vm.getArtifactPathByDeployedCode reverts
+    vm.expectRevert();
+    _validateNoPayloadStorageSlots(makeAddr('unknownPayload'));
+  }
 }

tests/mocks/PayloadWithStorage.sol

@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.10;
+
+import {IProposalGenericExecutor} from '../../src/interfaces/IProposalGenericExecutor.sol';
+
+/**
+ * @dev Mock payload that incorrectly declares a state variable.
+ * Used to test that _validateNoPayloadStorageSlots detects storage variables.
+ */
+contract PayloadWithStorage is IProposalGenericExecutor {
+  uint256 internal _randomStorageVariable;
+
+  function execute() external {
+    // do nothing just relax
+  }
+}