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feat: use require in SafeMath (#1187)

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* feat: use require in SafeMath

* fix: grammar with revert
This commit is contained in:
Brett Sun
2018-08-10 19:41:06 +01:00
committed by Nicolás Venturo
parent 6dab31288e
commit c9e91586e7
2 changed files with 18 additions and 18 deletions
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18
contracts/math/SafeMath.sol
View File

@ -3,15 +3,15 @@ pragma solidity ^0.4.24;
/** /**
* @title SafeMath * @title SafeMath
* @dev Math operations with safety checks that throw on error * @dev Math operations with safety checks that revert on error
*/ */
library SafeMath { library SafeMath {
/** /**
* @dev Multiplies two numbers, throws on overflow. * @dev Multiplies two numbers, reverts on overflow.
*/ */
function mul(uint256 _a, uint256 _b) internal pure returns (uint256) { function mul(uint256 _a, uint256 _b) internal pure returns (uint256) {
// Gas optimization: this is cheaper than asserting 'a' not being zero, but the // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
// benefit is lost if 'b' is also tested. // benefit is lost if 'b' is also tested.
// See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522 // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
if (_a == 0) { if (_a == 0) {
@ -19,7 +19,7 @@ library SafeMath {
} }
uint256 c = _a * _b; uint256 c = _a * _b;
assert(c / _a == _b); require(c / _a == _b);
return c; return c;
} }
@ -28,7 +28,7 @@ library SafeMath {
* @dev Integer division of two numbers, truncating the quotient. * @dev Integer division of two numbers, truncating the quotient.
*/ */
function div(uint256 _a, uint256 _b) internal pure returns (uint256) { function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
// assert(_b > 0); // Solidity automatically throws when dividing by 0 require(_b > 0); // Solidity only automatically asserts when dividing by 0
uint256 c = _a / _b; uint256 c = _a / _b;
// assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
@ -36,21 +36,21 @@ library SafeMath {
} }
/** /**
* @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend). * @dev Subtracts two numbers, reverts on overflow (i.e. if subtrahend is greater than minuend).
*/ */
function sub(uint256 _a, uint256 _b) internal pure returns (uint256) { function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
assert(_b <= _a); require(_b <= _a);
uint256 c = _a - _b; uint256 c = _a - _b;
return c; return c;
} }
/** /**
* @dev Adds two numbers, throws on overflow. * @dev Adds two numbers, reverts on overflow.
*/ */
function add(uint256 _a, uint256 _b) internal pure returns (uint256) { function add(uint256 _a, uint256 _b) internal pure returns (uint256) {
uint256 c = _a + _b; uint256 c = _a + _b;
assert(c >= _a); require(c >= _a);
return c; return c;
} }

18
test/math/SafeMath.test.js
View File

@ -1,4 +1,4 @@
const { assertJump } = require('../helpers/assertJump'); const { assertRevert } = require('../helpers/assertRevert');
const BigNumber = web3.BigNumber; const BigNumber = web3.BigNumber;
const SafeMathMock = artifacts.require('SafeMathMock'); const SafeMathMock = artifacts.require('SafeMathMock');
@ -22,11 +22,11 @@ contract('SafeMath', () => {
result.should.be.bignumber.equal(a.plus(b)); result.should.be.bignumber.equal(a.plus(b));
}); });
it('throws an error on addition overflow', async function () { it('throws a revert error on addition overflow', async function () {
const a = MAX_UINT; const a = MAX_UINT;
const b = new BigNumber(1); const b = new BigNumber(1);
await assertJump(this.safeMath.add(a, b)); await assertRevert(this.safeMath.add(a, b));
}); });
}); });
@ -39,11 +39,11 @@ contract('SafeMath', () => {
result.should.be.bignumber.equal(a.minus(b)); result.should.be.bignumber.equal(a.minus(b));
}); });
it('throws an error if subtraction result would be negative', async function () { it('throws a revert error if subtraction result would be negative', async function () {
const a = new BigNumber(1234); const a = new BigNumber(1234);
const b = new BigNumber(5678); const b = new BigNumber(5678);
await assertJump(this.safeMath.sub(a, b)); await assertRevert(this.safeMath.sub(a, b));
}); });
}); });
@ -64,11 +64,11 @@ contract('SafeMath', () => {
result.should.be.bignumber.equal(a.times(b)); result.should.be.bignumber.equal(a.times(b));
}); });
it('throws an error on multiplication overflow', async function () { it('throws a revert error on multiplication overflow', async function () {
const a = MAX_UINT; const a = MAX_UINT;
const b = new BigNumber(2); const b = new BigNumber(2);
await assertJump(this.safeMath.mul(a, b)); await assertRevert(this.safeMath.mul(a, b));
}); });
}); });
@ -81,11 +81,11 @@ contract('SafeMath', () => {
result.should.be.bignumber.equal(a.div(b)); result.should.be.bignumber.equal(a.div(b));
}); });
it('throws an error on zero division', async function () { it('throws a revert error on zero division', async function () {
const a = new BigNumber(5678); const a = new BigNumber(5678);
const b = new BigNumber(0); const b = new BigNumber(0);
await assertJump(this.safeMath.div(a, b)); await assertRevert(this.safeMath.div(a, b));
}); });
}); });
}); });