documentation

contracts/token/OnTokenTransferAdapter.sol

@@ -4,14 +4,21 @@ pragma solidity ^0.8.20;
 
 import "@openzeppelin/contracts/interfaces/IERC1363Receiver.sol";
 
+/**
+ * @dev This contract exposes the 667 `onTokenTransfer` hook on top of {ERC-1363-onTransferReceived}.
+ *
+ * Inheriting from this adapter makes every `ERC1363Receiver` contract automatically compatible with tokens, such as
+ * Chainlink's Link, that implement the 667 interface for transferAndCall.
+ */
 abstract contract OnTokenTransferAdapter is IERC1363Receiver {
     function onTokenTransfer(address from, uint256 amount, bytes calldata data) public virtual returns (bool) {
         // Rewrite call as IERC1363.onTransferReceived
         // This uses delegate call to keep the correct sender (token contracts)
         //
-        // TODO: use operator = 0 or operator = from ?
+        // Note that since 667 doesn't implement `transferFromAndCall`, this hook was called by a simple
+        // `transferAndCall` and thus the operator is necessarily the `from` address.
         (bool success, bytes memory returndata) = address(this).delegatecall(
-            abi.encodeCall(IERC1363Receiver.onTransferReceived, (address(0), from, amount, data))
+            abi.encodeCall(IERC1363Receiver.onTransferReceived, (from, from, amount, data))
         );
         // check success and return as boolean
         return