From dade5406c44e6bb82e6c593ad8b84270c1b2cab4 Mon Sep 17 00:00:00 2001
From: Ameesha Agrawal <ameeshaagrawal12@gmail.com>
Date: Thu, 2 Oct 2025 16:43:34 +0530
Subject: [PATCH] feat: payload revert

---
 contracts/evmx/helpers/AsyncPromise.sol | 40 ++++++++++++++++++++-----
 contracts/evmx/interfaces/IPromise.sol  |  5 ++++
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/contracts/evmx/helpers/AsyncPromise.sol b/contracts/evmx/helpers/AsyncPromise.sol
index f727947d..012b9a4e 100644
--- a/contracts/evmx/helpers/AsyncPromise.sol
+++ b/contracts/evmx/helpers/AsyncPromise.sol
@@ -38,8 +38,16 @@ abstract contract AsyncPromiseStorage is IPromise {
     /// @notice The callback data to be used when the promise is resolved.
     bytes public callbackData;
 
-    // slots [53-102] reserved for gap
-    uint256[50] _gap_after;
+    // slot 53
+    /// @notice The revert handler selector of the promise
+    bytes4 public revertHandlerSelector;
+
+    // slot 54
+    /// @notice The revert handler data of the promise
+    bytes public revertHandlerData;
+
+    // slots [55-102] reserved for gap
+    uint256[48] _gap_after;
 
     // slots 103-154 (51) reserved for addr resolver util
 }
@@ -133,7 +141,14 @@ contract AsyncPromise is AsyncPromiseStorage, Initializable, AddressResolverUtil
     /// @dev Only callable by the watcher.
     /// @dev handleRevert function can be retried till it succeeds
     function _handleRevert(bytes32 payloadId_) internal {
-        try IAppGateway(localInvoker).handleRevert(payloadId_) {} catch {
+        bytes memory combinedCalldata = abi.encodePacked(
+            revertHandlerSelector,
+            abi.encode(revertHandlerData, payloadId_)
+        );
+
+        (bool success, , ) = localInvoker.tryCall(0, gasleft(), 0, combinedCalldata);
+
+        if (!success) {
             // todo: in this case, promise will stay unresolved
             revert PromiseRevertFailed();
         }
@@ -143,20 +158,31 @@ contract AsyncPromise is AsyncPromiseStorage, Initializable, AddressResolverUtil
     /// @param selector_ The function selector for the callback.
     /// @param data_ The data to be passed to the callback.
     function then(bytes4 selector_, bytes memory data_) external override {
-        if (msg.sender != localInvoker) revert NotInvoker();
         // if the promise is already set up, revert
         if (state != AsyncPromiseState.WAITING_FOR_CALLBACK_SELECTOR) {
             revert PromiseAlreadySetUp();
         }
-        if (watcher__().latestAsyncPromise() != address(this)) revert NotLatestPromise();
-        if (requestCount != watcher__().getCurrentRequestCount()) revert RequestCountMismatch();
-
+        _validate();
         // if the promise is waiting for the callback selector, set it and update the state
         callbackSelector = selector_;
         callbackData = data_;
         state = AsyncPromiseState.WAITING_FOR_CALLBACK_EXECUTION;
     }
 
+    function error(bytes4 selector_, bytes memory data_) external override {
+        _validate();
+        // if the promise is waiting for the callback selector, set it and update the state
+        revertHandlerSelector = selector_;
+        revertHandlerData = data_;
+        state = AsyncPromiseState.WAITING_FOR_CALLBACK_EXECUTION;
+    }
+
+    function _validate() internal {
+        if (msg.sender != localInvoker) revert NotInvoker();
+        if (watcher__().latestAsyncPromise() != address(this)) revert NotLatestPromise();
+        if (requestCount != watcher__().getCurrentRequestCount()) revert RequestCountMismatch();
+    }
+
     /**
      * @notice Rescues funds from the contract if they are locked by mistake. This contract does not
      * theoretically need this function but it is added for safety.
diff --git a/contracts/evmx/interfaces/IPromise.sol b/contracts/evmx/interfaces/IPromise.sol
index f323ae69..c898e16e 100644
--- a/contracts/evmx/interfaces/IPromise.sol
+++ b/contracts/evmx/interfaces/IPromise.sol
@@ -32,6 +32,11 @@ interface IPromise {
     /// @param data_ The data to be passed to the callback.
     function then(bytes4 selector_, bytes memory data_) external;
 
+    /// @notice Sets the revert handler selector and data for the promise.
+    /// @param selector_ The function selector for the revert handler.
+    /// @param data_ The data to be passed to the revert handler.
+    function error(bytes4 selector_, bytes memory data_) external;
+
     /// @notice Marks the promise as resolved and executes the callback if set.
     /// @dev Only callable by the watcher precompile.
     /// @param resolvedPromise_ The data returned from the async payload execution.