Merge pull request #957 from danlipert/safemath-tests

Add SafeMath test showing testing for revert
pull/7/head
yann300 6 years ago committed by GitHub
commit 6c2084d1d0
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  1. 68
      remix-tests/tests/examples_4/SafeMath.sol
  2. 31
      remix-tests/tests/examples_4/SafeMathProxy.sol
  3. 86
      remix-tests/tests/examples_4/SafeMath_test.sol

@ -0,0 +1,68 @@
// Copyright (c) 2016 Smart Contract Solutions, Inc.
pragma solidity ^0.4.24;
/**
* @title SafeMath
* @dev Math operations with safety checks that revert on error
*/
library SafeMath {
/**
* @dev Multiplies two numbers, reverts on 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-solidity/pull/522
if (_a == 0) {
return 0;
}
uint256 c = _a * _b;
require(c / _a == _b);
return c;
}
/**
* @dev Integer division of two numbers truncating the quotient, reverts on division by zero.
*/
function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
require(_b > 0); // Solidity only automatically asserts when dividing by 0
uint256 c = _a / _b;
// assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
return c;
}
/**
* @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) {
require(_b <= _a);
uint256 c = _a - _b;
return c;
}
/**
* @dev Adds two numbers, reverts on overflow.
*/
function add(uint256 _a, uint256 _b) internal pure returns (uint256) {
uint256 c = _a + _b;
require(c >= _a);
return c;
}
/**
* @dev Divides two numbers and returns the remainder (unsigned integer modulo),
* reverts when dividing by zero.
*/
function mod(uint256 a, uint256 b) internal pure returns (uint256) {
require(b != 0);
return a % b;
}
}

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pragma solidity ^0.4.24;
import "./SafeMath.sol";
/*
Using a proxy contract here allows revert-causing functions that contain
require() to return false rather than halt execution
https://truffleframework.com/tutorials/testing-for-throws-in-solidity-tests
*/
contract SafeMathProxy {
using SafeMath for uint;
function divProxy(uint256 a, uint256 b) returns (uint256) {
return a.div(b);
}
function mulProxy(uint256 a, uint256 b) returns (uint256) {
return a.mul(b);
}
function subProxy(uint256 a, uint256 b) returns (uint256) {
return a.sub(b);
}
function addProxy(uint256 a, uint256 b) returns (uint256) {
return a.add(b);
}
function modProxy(uint256 a, uint256 b) returns (uint256) {
return a.mod(b);
}
}

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pragma solidity ^0.4.24;
import "./remix_tests.sol";
import "./SafeMath.sol";
import "./SafeMathProxy.sol";
contract SafeMathTest {
SafeMathProxy safemathproxy;
function beforeAll() {
safemathproxy = new SafeMathProxy();
}
function unsafeMultiplicationShouldOverflow() public constant returns (bool) {
uint256 a = 4;
uint256 b = 2 ** 256 - 1;
return Assert.equal(
a * b,
2 ** 256 - 4,
"unsafe multiplication did not overflow"
);
}
function safeMultiplicationShouldRevert() public constant returns (bool) {
uint256 a = 4;
uint256 b = 2 ** 256 - 1;
return Assert.equal(
address(safemathproxy).call.gas(40000).value(0)("mulProxy",[a, b]),
false,
"safe multiplication did not revert"
);
}
function safeDivisionByZeroShouldRevert() public constant returns (bool) {
uint256 a = 4;
uint256 b = 0;
return Assert.equal(
address(safemathproxy).call.gas(40000).value(0)("divProxy", [a, b]),
false,
"safe division did not revert"
);
}
function unsafeSubtractShouldUnderflow() public constant returns (bool) {
uint256 a = 0;
uint256 b = a - 1;
return Assert.equal(
b,
2 ** 256 - 1,
"unsafe subtraction did not underflow"
);
}
function safeSubtractShouldRevert() public constant returns (bool) {
return Assert.equal(
address(safemathproxy).call.gas(40000).value(0)("subProxy", [0, 1]),
false,
"safe subtract should revert"
);
}
function unsafeAdditionShouldOverflow() public constant returns (bool) {
uint256 a = 1;
uint256 b = 2 ** 256 - 1;
return Assert.equal(a + b, 0, "unsafe addition did not overflow");
}
function safeAdditionShouldRevert() public constant returns (bool) {
uint256 a = 1;
uint256 b = 2 ** 256 - 1;
return Assert.equal(
address(safemathproxy).call.gas(40000).value(0)("addProxy", [a, b]),
false,
"safe addition should revert"
);
}
function safeModulusShouldRevert() public constant returns (bool) {
uint256 a = 1;
uint256 b = 0;
return Assert.equal(
address(safemathproxy).call.gas(40000).value(0)("modProxy", [a, b]),
false,
"safe modulus did not revert"
);
}
}
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