Features/refactoring

contracts/Keep3rGovernance.sol

@@ -1,190 +1,9 @@
-pragma solidity ^0.5.17;
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.6.6;
 pragma experimental ABIEncoderV2;
 
-// From https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/math/Math.sol
-// Subject to the MIT license.
-
-/**
- * @dev Wrappers over Solidity's arithmetic operations with added overflow
- * checks.
- *
- * Arithmetic operations in Solidity wrap on overflow. This can easily result
- * in bugs, because programmers usually assume that an overflow raises an
- * error, which is the standard behavior in high level programming languages.
- * `SafeMath` restores this intuition by reverting the transaction when an
- * operation overflows.
- *
- * Using this library instead of the unchecked operations eliminates an entire
- * class of bugs, so it's recommended to use it always.
- */
-library SafeMath {
-    /**
-     * @dev Returns the addition of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `+` operator.
-     *
-     * Requirements:
-     * - Addition cannot overflow.
-     */
-    function add(uint256 a, uint256 b) internal pure returns (uint256) {
-        uint256 c = a + b;
-        require(c >= a, "SafeMath: addition overflow");
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the addition of two unsigned integers, reverting with custom message on overflow.
-     *
-     * Counterpart to Solidity's `+` operator.
-     *
-     * Requirements:
-     * - Addition cannot overflow.
-     */
-    function add(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        uint256 c = a + b;
-        require(c >= a, errorMessage);
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the subtraction of two unsigned integers, reverting on underflow (when the result is negative).
-     *
-     * Counterpart to Solidity's `-` operator.
-     *
-     * Requirements:
-     * - Subtraction cannot underflow.
-     */
-    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
-        return sub(a, b, "SafeMath: subtraction underflow");
-    }
-
-    /**
-     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on underflow (when the result is negative).
-     *
-     * Counterpart to Solidity's `-` operator.
-     *
-     * Requirements:
-     * - Subtraction cannot underflow.
-     */
-    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        require(b <= a, errorMessage);
-        uint256 c = a - b;
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `*` operator.
-     *
-     * Requirements:
-     * - Multiplication cannot overflow.
-     */
-    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
-        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-        // benefit is lost if 'b' is also tested.
-        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
-        if (a == 0) {
-            return 0;
-        }
-
-        uint256 c = a * b;
-        require(c / a == b, "SafeMath: multiplication overflow");
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the multiplication of two unsigned integers, reverting on overflow.
-     *
-     * Counterpart to Solidity's `*` operator.
-     *
-     * Requirements:
-     * - Multiplication cannot overflow.
-     */
-    function mul(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
-        // benefit is lost if 'b' is also tested.
-        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
-        if (a == 0) {
-            return 0;
-        }
-
-        uint256 c = a * b;
-        require(c / a == b, errorMessage);
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the integer division of two unsigned integers.
-     * Reverts on division by zero. The result is rounded towards zero.
-     *
-     * Counterpart to Solidity's `/` operator. Note: this function uses a
-     * `revert` opcode (which leaves remaining gas untouched) while Solidity
-     * uses an invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
-    function div(uint256 a, uint256 b) internal pure returns (uint256) {
-        return div(a, b, "SafeMath: division by zero");
-    }
-
-    /**
-     * @dev Returns the integer division of two unsigned integers.
-     * Reverts with custom message on division by zero. The result is rounded towards zero.
-     *
-     * Counterpart to Solidity's `/` operator. Note: this function uses a
-     * `revert` opcode (which leaves remaining gas untouched) while Solidity
-     * uses an invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
-    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        // Solidity only automatically asserts when dividing by 0
-        require(b > 0, errorMessage);
-        uint256 c = a / b;
-        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
-
-        return c;
-    }
-
-    /**
-     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
-     * Reverts when dividing by zero.
-     *
-     * Counterpart to Solidity's `%` operator. This function uses a `revert`
-     * opcode (which leaves remaining gas untouched) while Solidity uses an
-     * invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
-    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
-        return mod(a, b, "SafeMath: modulo by zero");
-    }
-
-    /**
-     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
-     * Reverts with custom message when dividing by zero.
-     *
-     * Counterpart to Solidity's `%` operator. This function uses a `revert`
-     * opcode (which leaves remaining gas untouched) while Solidity uses an
-     * invalid opcode to revert (consuming all remaining gas).
-     *
-     * Requirements:
-     * - The divisor cannot be zero.
-     */
-    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
-        require(b != 0, errorMessage);
-        return a % b;
-    }
-}
+import '@openzeppelin/contracts/math/SafeMath.sol';
+import "./interfaces/DelegateInterface.sol";
 
 contract Governance {
     using SafeMath for uint;
@@ -516,7 +335,7 @@ contract Governance {
         VOTER = DelegateInterface(token_);
     }
 
-    function() external payable { }
+    receive() external payable { }
 
     function setDelay(uint delay_) public {
         require(msg.sender == address(this), "Timelock::setDelay: Call must come from Timelock.");
@@ -566,7 +385,7 @@ contract Governance {
         }
 
         // solium-disable-next-line security/no-call-value
-        (bool success, bytes memory returnData) = target.call.value(value)(callData);
+        (bool success, bytes memory returnData) = target.call{value: value}(callData);
         require(success, "Timelock::executeTransaction: Transaction execution reverted.");
 
         emit ExecuteTransaction(txHash, target, value, signature, data, eta);
@@ -578,9 +397,4 @@ contract Governance {
         // solium-disable-next-line security/no-block-members
         return block.timestamp;
     }
-}
-
-interface DelegateInterface {
-    function getPriorVotes(address account, uint blockNumber) external view returns (uint);
-    function totalBonded() external view returns (uint);
-}
+}