refactor and enhance testing utilities

src/interfaces/cctp/IMessageTransmitter.sol

@@ -1,27 +1,87 @@
-/*
- * Copyright (c) 2022, Circle Internet Financial Limited.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// SPDX-License-Identifier: Apache 2
 pragma solidity ^0.8.0;
 
-import "./IRelayer.sol";
-import "./IReceiver.sol";
+interface IMessageTransmitter {
+	event MessageSent(bytes message);
 
-/**
- * @title IMessageTransmitter
- * @notice Interface for message transmitters, which both relay and receive messages.
- */
-interface IMessageTransmitter is IRelayer, IReceiver {
+	/**
+	 * @notice Emitted when tokens are minted
+	 * @param _mintRecipient recipient address of minted tokens
+	 * @param _amount amount of minted tokens
+	 * @param _mintToken contract address of minted token
+	 */
+	event MintAndWithdraw(
+		address _mintRecipient,
+		uint256 _amount,
+		address _mintToken
+	);
 
+	/**
+	 * @notice Receive a message. Messages with a given nonce
+	 * can only be broadcast once for a (sourceDomain, destinationDomain)
+	 * pair. The message body of a valid message is passed to the
+	 * specified recipient for further processing.
+	 *
+	 * @dev Attestation format:
+	 * A valid attestation is the concatenated 65-byte signature(s) of exactly
+	 * `thresholdSignature` signatures, in increasing order of attester address.
+	 * ***If the attester addresses recovered from signatures are not in
+	 * increasing order, signature verification will fail.***
+	 * If incorrect number of signatures or duplicate signatures are supplied,
+	 * signature verification will fail.
+	 *
+	 * Message format:
+	 * Field Bytes Type Index
+	 * version 4 uint32 0
+	 * sourceDomain 4 uint32 4
+	 * destinationDomain 4 uint32 8
+	 * nonce 8 uint64 12
+	 * sender 32 bytes32 20
+	 * recipient 32 bytes32 52
+	 * messageBody dynamic bytes 84
+	 * @param _message Message bytes
+	 * @param _attestation Concatenated 65-byte signature(s) of `_message`, in increasing order
+	 * of the attester address recovered from signatures.
+	 * @return success bool, true if successful
+	 */
+	function receiveMessage(
+		bytes memory _message,
+		bytes calldata _attestation
+	) external returns (bool success);
+
+	function attesterManager() external view returns (address);
+
+	function availableNonces(uint32 domain) external view returns (uint64);
+
+	function getNumEnabledAttesters() external view returns (uint256);
+
+	function isEnabledAttester(address _attester) external view returns (bool);
+
+	function localDomain() external view returns (uint32);
+
+	function maxMessageBodySize() external view returns (uint256);
+
+	function owner() external view returns (address);
+
+	function paused() external view returns (bool);
+
+	function pauser() external view returns (address);
+
+	function rescuer() external view returns (address);
+
+	function version() external view returns (uint32);
+
+	// owner only methods
+	function transferOwnership(address newOwner) external;
+
+	function updateAttesterManager(address _newAttesterManager) external;
+
+	// attester manager only methods
+	function getEnabledAttester(uint256 _index) external view returns (address);
+
+	function disableAttester(address _attester) external;
+
+	function enableAttester(address _attester) external;
+
+	function setSignatureThreshold(uint256 newSignatureThreshold) external;
 }

src/interfaces/cctp/ITokenMessenger.sol

@@ -1,53 +1,84 @@
-/*
- * Copyright (c) 2022, Circle Internet Financial Limited.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+// SPDX-License-Identifier: Apache 2
 pragma solidity ^0.8.0;
 
-/**
- * @title TokenMessenger
- * @notice Sends messages and receives messages to/from MessageTransmitters
- * and to/from TokenMinters
- */
+import {IMessageTransmitter} from "./IMessageTransmitter.sol";
+import {ITokenMinter} from "./ITokenMinter.sol";
+
 interface ITokenMessenger {
-   /**
+    /**
+     * @notice Deposits and burns tokens from sender to be minted on destination domain.
+     * Emits a `DepositForBurn` event.
+     * @dev reverts if:
+     * - given burnToken is not supported
+     * - given destinationDomain has no CircleBridge registered
+     * - transferFrom() reverts. For example, if sender's burnToken balance or approved allowance
+     * to this contract is less than `amount`.
+     * - burn() reverts. For example, if `amount` is 0.
+     * - MessageTransmitter returns false or reverts.
+     * @param _amount amount of tokens to burn
+     * @param _destinationDomain destination domain (ETH = 0, AVAX = 1)
+     * @param _mintRecipient address of mint recipient on destination domain
+     * @param _burnToken address of contract to burn deposited tokens, on local domain
+     * @return _nonce unique nonce reserved by message
+     */
+    function depositForBurn(
+        uint256 _amount,
+        uint32 _destinationDomain,
+        bytes32 _mintRecipient,
+        address _burnToken
+    ) external returns (uint64 _nonce);
+
+    /**
      * @notice Deposits and burns tokens from sender to be minted on destination domain. The mint
-     * on the destination domain must be called by `destinationCaller`.
-     * WARNING: if the `destinationCaller` does not represent a valid address as bytes32, then it will not be possible
+     * on the destination domain must be called by `_destinationCaller`.
+     * WARNING: if the `_destinationCaller` does not represent a valid address as bytes32, then it will not be possible
      * to broadcast the message on the destination domain. This is an advanced feature, and the standard
      * depositForBurn() should be preferred for use cases where a specific destination caller is not required.
      * Emits a `DepositForBurn` event.
      * @dev reverts if:
      * - given destinationCaller is zero address
      * - given burnToken is not supported
-     * - given destinationDomain has no TokenMessenger registered
+     * - given destinationDomain has no CircleBridge registered
      * - transferFrom() reverts. For example, if sender's burnToken balance or approved allowance
      * to this contract is less than `amount`.
      * - burn() reverts. For example, if `amount` is 0.
      * - MessageTransmitter returns false or reverts.
-     * @param amount amount of tokens to burn
-     * @param destinationDomain destination domain
-     * @param mintRecipient address of mint recipient on destination domain
-     * @param burnToken address of contract to burn deposited tokens, on local domain
-     * @param destinationCaller caller on the destination domain, as bytes32
-     * @return nonce unique nonce reserved by message
+     * @param _amount amount of tokens to burn
+     * @param _destinationDomain destination domain
+     * @param _mintRecipient address of mint recipient on destination domain
+     * @param _burnToken address of contract to burn deposited tokens, on local domain
+     * @param _destinationCaller caller on the destination domain, as bytes32
+     * @return _nonce unique nonce reserved by message
      */
     function depositForBurnWithCaller(
-        uint256 amount,
-        uint32 destinationDomain,
-        bytes32 mintRecipient,
-        address burnToken,
-        bytes32 destinationCaller
-    ) external returns (uint64 nonce);
-}
+        uint256 _amount,
+        uint32 _destinationDomain,
+        bytes32 _mintRecipient,
+        address _burnToken,
+        bytes32 _destinationCaller
+    ) external returns (uint64 _nonce);
+
+    function localMessageTransmitter() external view returns (IMessageTransmitter);
+
+    function localMinter() external view returns (ITokenMinter);
+
+    function messageBodyVersion() external view returns (uint32);
+
+    function owner() external view returns (address);
+
+    function pendingOwner() external view returns (address);
+
+    function rescuer() external view returns (address);
+
+    function remoteTokenMessengers(uint32 domain) external view returns (bytes32);
+
+    function addRemoteTokenMessenger(uint32 domain, bytes32 tokenMessenger) external;
+
+    function handleReceiveMessage(uint32 _remoteDomain, bytes32 _sender, bytes memory messageBody)
+        external
+        view
+        returns (bool);
+
+    // owner only methods
+    function transferOwnership(address newOwner) external;
+}

src/interfaces/cctp/ITokenMinter.sol

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: Apache 2
+pragma solidity ^0.8.0;
+
+/**
+ * @title ITokenMinter
+ * @notice interface for minter of tokens that are mintable, burnable, and interchangeable
+ * across domains.
+ */
+interface ITokenMinter {
+	function tokenController() external view returns (address);
+
+	function burnLimitsPerMessage(address token) external view returns (uint256);
+
+	function remoteTokensToLocalTokens(bytes32 sourceIdHash) external view returns (address);
+
+	function linkTokenPair(address localToken, uint32 remoteDomain, bytes32 remoteToken) external;
+}