feat: add SafeERC20 dependency

contracts/dependencies/openzeppelin/contracts/Address.sol

@@ -1,5 +1,7 @@
-// SPDX-License-Identifier: AGPL-3.0
-pragma solidity 0.8.10;
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)
+
+pragma solidity ^0.8.0;
 
 /**
  * @dev Collection of functions related to the address type
@@ -23,16 +25,15 @@ library Address {
  * ====
  */
  function isContract(address account) internal view returns (bool) {
- // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
- // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
- // for accounts without code, i.e. `keccak256('')`
- bytes32 codehash;
- bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
- // solhint-disable-next-line no-inline-assembly
+ // This method relies on extcodesize, which returns 0 for contracts in
+ // construction, since the code is only stored at the end of the
+ // constructor execution.
+
+ uint256 size;
  assembly {
- codehash := extcodehash(account)
+ size := extcodesize(account)
  }
- return (codehash != accountHash && codehash != 0x0);
+ return size > 0;
  }
 
  /**
@@ -54,8 +55,166 @@ library Address {
  function sendValue(address payable recipient, uint256 amount) internal {
  require(address(this).balance >= amount, 'Address: insufficient balance');
 
- // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
  (bool success, ) = recipient.call{value: amount}('');
  require(success, 'Address: unable to send value, recipient may have reverted');
  }
+
+ /**
+ * @dev Performs a Solidity function call using a low level `call`. A
+ * plain `call` is an unsafe replacement for a function call: use this
+ * function instead.
+ *
+ * If `target` reverts with a revert reason, it is bubbled up by this
+ * function (like regular Solidity function calls).
+ *
+ * Returns the raw returned data. To convert to the expected return value,
+ * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
+ *
+ * Requirements:
+ *
+ * - `target` must be a contract.
+ * - calling `target` with `data` must not revert.
+ *
+ * _Available since v3.1._
+ */
+ function functionCall(address target, bytes memory data) internal returns (bytes memory) {
+ return functionCall(target, data, 'Address: low-level call failed');
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
+ * `errorMessage` as a fallback revert reason when `target` reverts.
+ *
+ * _Available since v3.1._
+ */
+ function functionCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ return functionCallWithValue(target, data, 0, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but also transferring `value` wei to `target`.
+ *
+ * Requirements:
+ *
+ * - the calling contract must have an ETH balance of at least `value`.
+ * - the called Solidity function must be `payable`.
+ *
+ * _Available since v3.1._
+ */
+ function functionCallWithValue(
+ address target,
+ bytes memory data,
+ uint256 value
+ ) internal returns (bytes memory) {
+ return functionCallWithValue(target, data, value, 'Address: low-level call with value failed');
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
+ * with `errorMessage` as a fallback revert reason when `target` reverts.
+ *
+ * _Available since v3.1._
+ */
+ function functionCallWithValue(
+ address target,
+ bytes memory data,
+ uint256 value,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ require(address(this).balance >= value, 'Address: insufficient balance for call');
+ require(isContract(target), 'Address: call to non-contract');
+
+ (bool success, bytes memory returndata) = target.call{value: value}(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but performing a static call.
+ *
+ * _Available since v3.3._
+ */
+ function functionStaticCall(
+ address target,
+ bytes memory data
+ ) internal view returns (bytes memory) {
+ return functionStaticCall(target, data, 'Address: low-level static call failed');
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+ * but performing a static call.
+ *
+ * _Available since v3.3._
+ */
+ function functionStaticCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal view returns (bytes memory) {
+ require(isContract(target), 'Address: static call to non-contract');
+
+ (bool success, bytes memory returndata) = target.staticcall(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
+ * but performing a delegate call.
+ *
+ * _Available since v3.4._
+ */
+ function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
+ return functionDelegateCall(target, data, 'Address: low-level delegate call failed');
+ }
+
+ /**
+ * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
+ * but performing a delegate call.
+ *
+ * _Available since v3.4._
+ */
+ function functionDelegateCall(
+ address target,
+ bytes memory data,
+ string memory errorMessage
+ ) internal returns (bytes memory) {
+ require(isContract(target), 'Address: delegate call to non-contract');
+
+ (bool success, bytes memory returndata) = target.delegatecall(data);
+ return verifyCallResult(success, returndata, errorMessage);
+ }
+
+ /**
+ * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
+ * revert reason using the provided one.
+ *
+ * _Available since v4.3._
+ */
+ function verifyCallResult(
+ bool success,
+ bytes memory returndata,
+ string memory errorMessage
+ ) internal pure returns (bytes memory) {
+ if (success) {
+ return returndata;
+ } else {
+ // Look for revert reason and bubble it up if present
+ if (returndata.length > 0) {
+ // The easiest way to bubble the revert reason is using memory via assembly
+
+ assembly {
+ let returndata_size := mload(returndata)
+ revert(add(32, returndata), returndata_size)
+ }
+ } else {
+ revert(errorMessage);
+ }
+ }
+ }
 }

contracts/dependencies/openzeppelin/contracts/SafeERC20.sol

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: MIT
+// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)
+
+pragma solidity ^0.8.0;
+
+import './IERC20.sol';
+import './Address.sol';
+
+/**
+ * @title SafeERC20
+ * @dev Wrappers around ERC20 operations that throw on failure (when the token
+ * contract returns false). Tokens that return no value (and instead revert or
+ * throw on failure) are also supported, non-reverting calls are assumed to be
+ * successful.
+ * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
+ * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
+ */
+library SafeERC20 {
+ using Address for address;
+
+ function safeTransfer(IERC20 token, address to, uint256 value) internal {
+ _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
+ }
+
+ function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
+ _callOptionalReturn(
+ token,
+ abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
+ );
+ }
+
+ /**
+ * @dev Deprecated. This function has issues similar to the ones found in
+ * {IERC20-approve}, and its usage is discouraged.
+ *
+ * Whenever possible, use {safeIncreaseAllowance} and
+ * {safeDecreaseAllowance} instead.
+ */
+ function safeApprove(IERC20 token, address spender, uint256 value) internal {
+ // safeApprove should only be called when setting an initial allowance,
+ // or when resetting it to zero. To increase and decrease it, use
+ // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
+ require(
+ (value == 0) || (token.allowance(address(this), spender) == 0),
+ 'SafeERC20: approve from non-zero to non-zero allowance'
+ );
+ _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
+ }
+
+ function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
+ uint256 newAllowance = token.allowance(address(this), spender) + value;
+ _callOptionalReturn(
+ token,
+ abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
+ );
+ }
+
+ function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
+ unchecked {
+ uint256 oldAllowance = token.allowance(address(this), spender);
+ require(oldAllowance >= value, 'SafeERC20: decreased allowance below zero');
+ uint256 newAllowance = oldAllowance - value;
+ _callOptionalReturn(
+ token,
+ abi.encodeWithSelector(token.approve.selector, spender, newAllowance)
+ );
+ }
+ }
+
+ /**
+ * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
+ * on the return value: the return value is optional (but if data is returned, it must not be false).
+ * @param token The token targeted by the call.
+ * @param data The call data (encoded using abi.encode or one of its variants).
+ */
+ function _callOptionalReturn(IERC20 token, bytes memory data) private {
+ // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
+ // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
+ // the target address contains contract code and also asserts for success in the low-level call.
+
+ bytes memory returndata = address(token).functionCall(data, 'SafeERC20: low-level call failed');
+ if (returndata.length > 0) {
+ // Return data is optional
+ require(abi.decode(returndata, (bool)), 'SafeERC20: ERC20 operation did not succeed');
+ }
+ }
+}