Merge pull request #18 from axieinfinity/feature/lib-native-transfer

feat: add `LibNativeTransfer`

foundry.toml

@@ -7,6 +7,7 @@ ffi = true
 # See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options
 
 remappings = [
+    'contract-libs/=src/',
     'forge-std/=lib/forge-std/src/',
     'ds-test/=lib/forge-std/lib/ds-test/src/',
     '@openzeppelin/=lib/openzeppelin-contracts/',

src/transfers/LibNativeTransfer.sol

@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import { LibErrorHandler } from "../LibErrorHandler.sol";
+
+/**
+ * @title NativeTransferHelper
+ */
+library LibNativeTransfer {
+  using LibErrorHandler for bool;
+
+  /**
+   * @dev Transfers Native Coin and wraps result for the method caller to a recipient.
+   */
+  function transfer(address to, uint256 value, uint256 gasAmount) internal {
+    (bool success, bytes memory returnOrRevertData) = trySendValue(to, value, gasAmount);
+    success.handleRevert(bytes4(0x0), returnOrRevertData);
+  }
+
+  /**
+   * @dev Unsafe send `amount` Native to the address `to`. If the sender's balance is insufficient,
+   * the call does not revert.
+   *
+   * Note:
+   * - Does not assert whether the balance of sender is sufficient.
+   * - Does not assert whether the recipient accepts NATIVE.
+   * - Consider using `ReentrancyGuard` before calling this function.
+   *
+   */
+  function trySendValue(address to, uint256 value, uint256 gasAmount)
+    internal
+    returns (bool success, bytes memory returnOrRevertData)
+  {
+    (success, returnOrRevertData) = to.call{ value: value, gas: gasAmount }("");
+  }
+}

test/transfers/LibNativeTransfer.t.sol

@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+import { Test } from "forge-std/Test.sol";
+import { LibNativeTransfer } from "contract-libs/transfers/LibNativeTransfer.sol";
+
+contract LibNativeTransferTest is Test {
+  function testFork_RevertWhen_TransferNativeToContractWithoutFallback_safeTransfer(
+    address any,
+    uint256 amount,
+    uint256 gas
+  ) external {
+    vm.deal(any, amount);
+    vm.expectRevert();
+    vm.prank(any);
+    LibNativeTransfer.transfer(address(this), amount, gas);
+  }
+
+  function testConcrete_TransferNative(uint256 gas) external {
+    LibNativeTransfer.transfer(address(0xBEEF), 1e18, gas);
+    assertEq(address(0xBEEF).balance, 1e18);
+  }
+
+  function testFork_TransferNativeToRecipient(address recipient, uint256 amount, uint256 gas) external {
+    // Transferring to msg.sender can fail because it's possible to overflow their ETH balance as it begins non-zero.
+    if (recipient.code.length > 0 || uint256(uint160(recipient)) <= 18 || recipient == msg.sender) return;
+
+    amount = bound(amount, 0, address(this).balance);
+    LibNativeTransfer.transfer(recipient, amount, gas);
+
+    assertEq(recipient.balance, amount);
+  }
+}