Add ILiquidityLayerRouter (#1378)

solidity/contracts/Router.sol

@@ -161,8 +161,8 @@ abstract contract Router is HyperlaneConnectionClient, IMessageRecipient {
         uint256 _gasAmount,
         uint256 _gasPayment,
         address _gasPaymentRefundAddress
-    ) internal {
-        bytes32 _messageId = _dispatch(_destinationDomain, _messageBody);
+    ) internal returns (bytes32 _messageId) {
+        _messageId = _dispatch(_destinationDomain, _messageBody);
         // Call the IGP even if the gas payment is zero. This is to support on-chain
         // fee quoting in IGPs, which should always revert if gas payment is insufficient.
         interchainGasPaymaster.payForGas{value: _gasPayment}(

solidity/contracts/middleware/liquidity-layer/LiquidityLayerRouter.sol

@@ -3,17 +3,17 @@ pragma solidity ^0.8.13;
 
 import {Router} from "../../Router.sol";
 
-import {IMessageRecipient} from "../../../interfaces/IMessageRecipient.sol";
+import {ILiquidityLayerRouter} from "../../../interfaces/ILiquidityLayerRouter.sol";
 import {ICircleBridge} from "./interfaces/circle/ICircleBridge.sol";
 import {ICircleMessageTransmitter} from "./interfaces/circle/ICircleMessageTransmitter.sol";
 import {ILiquidityLayerAdapter} from "./interfaces/ILiquidityLayerAdapter.sol";
-import {ILiquidityLayerMessageRecipient} from "./interfaces/ILiquidityLayerMessageRecipient.sol";
+import {ILiquidityLayerMessageRecipient} from "../../../interfaces/ILiquidityLayerMessageRecipient.sol";
 
 import {TypeCasts} from "../../libs/TypeCasts.sol";
 
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 
-contract LiquidityLayerRouter is Router {
+contract LiquidityLayerRouter is Router, ILiquidityLayerRouter {
     // Token bridge => adapter address
     mapping(string => address) public liquidityLayerAdapters;
 
@@ -39,7 +39,7 @@ contract LiquidityLayerRouter is Router {
         address _token,
         uint256 _amount,
         string calldata _bridge
-    ) external payable {
+    ) external payable returns (bytes32) {
         ILiquidityLayerAdapter _adapter = _getAdapter(_bridge);
 
         // Transfer the tokens to the adapter
@@ -71,13 +71,14 @@ contract LiquidityLayerRouter is Router {
         );
 
         // Dispatch the _messageWithMetadata to the destination's LiquidityLayerRouter.
-        _dispatchWithGas(
-            _destinationDomain,
-            _messageWithMetadata,
-            0, // TODO eventually accommodate gas amounts
-            msg.value,
-            msg.sender
-        );
+        return
+            _dispatchWithGas(
+                _destinationDomain,
+                _messageWithMetadata,
+                0, // TODO eventually accommodate gas amounts
+                msg.value,
+                msg.sender
+            );
     }
 
     // Handles a message from an enrolled remote LiquidityLayerRouter

solidity/contracts/test/TestLiquidityLayerMessageRecipient.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 pragma solidity ^0.8.13;
 
-import {ILiquidityLayerMessageRecipient} from "../middleware/liquidity-layer/interfaces/ILiquidityLayerMessageRecipient.sol";
+import {ILiquidityLayerMessageRecipient} from "../../interfaces/ILiquidityLayerMessageRecipient.sol";
 
 contract TestLiquidityLayerMessageRecipient is ILiquidityLayerMessageRecipient {
     event HandledWithTokens(

solidity/contracts/test/TestTokenRecipient.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: MIT OR Apache-2.0
 pragma solidity >=0.8.0;
 
-import {ILiquidityLayerMessageRecipient} from "../middleware/liquidity-layer/interfaces/ILiquidityLayerMessageRecipient.sol";
+import {ILiquidityLayerMessageRecipient} from "../../interfaces/ILiquidityLayerMessageRecipient.sol";
 
 contract TestTokenRecipient is ILiquidityLayerMessageRecipient {
     bytes32 public lastSender;

solidity/interfaces/ILiquidityLayerRouter.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT OR Apache-2.0
+pragma solidity >=0.6.11;
+
+import {Call} from "../contracts/Call.sol";
+
+interface ILiquidityLayerRouter {
+    function dispatchWithTokens(
+        uint32 _destinationDomain,
+        bytes32 _recipientAddress,
+        bytes calldata _messageBody,
+        address _token,
+        uint256 _amount,
+        string calldata _bridge
+    ) external payable returns (bytes32);
+}