Question

我试图根据这篇文章使用刚性来测试智能合约的要求：

http://truffleframework.com/tutorials/testing-for-throws-in-solidity-tests

这是合同，抛出代理合同和测试：

/* Testing with solidity tests. */

import "truffle/Assert.sol";
import "truffle/DeployedAddresses.sol";
import "../contracts/MyContract.sol";

contract TestMyContract {

function testInitialStoredValue() {
    MyContract mycontract = new MyContract();

    uint expected = 24;

    Assert.equal(mycontract.mynumber(), expected, "First number set should be 24.");
}

function testTheThrow() {
    MyContract mycontract = new MyContract(); 

    ThrowProxy throwproxy = new ThrowProxy(address(mycontract)); 
    uint num = 7;
    MyContract(address(throwproxy)).storeNum(num);

    bool r = throwproxy.execute.gas(200000)(); 

    Assert.isFalse(r, "Should be false because is should throw!");

}

function testNoThrow() {
    MyContract mycontract = new MyContract(); 

    ThrowProxy throwproxy = new ThrowProxy(address(mycontract)); 

    MyContract(address(throwproxy)).storeNum(22);

    bool r = throwproxy.execute.gas(200000)(); 

    Assert.isTrue(r, "Should be true because is should throw!");

}

}

// Proxy contract for testing throws
contract ThrowProxy {
  address public target;
  bytes data;

  function ThrowProxy(address _target) {
    target = _target;
  }

  //prime the data using the fallback function.
  function() {
    data = msg.data;
  }

  function execute() returns (bool) {
    return target.call(data);
  }
}

如果我运行测试，我会收到此错误：

如果我将storeNum函数从

更改为void

 function storeNum(uint mynum)
        public
        returns (bool)
    {
     require(mynum > 10);
     mynumber = mynum; 
     return true;    
    }

到

 function storeNum(uint mynum)
        public
    {
     require(mynum > 10);
     mynumber = mynum; 
     return true;    
    }

测试工作..

有什么想法吗？

我正在使用Truffle v4.1.11

Answer 1

让我们看看您的代码：

function storeNum(uint mynum)
        public
        returns (bool success)
    {
     require(mynum > 10);
     mynumber = mynum; 
     return true;    
    }

通过定义returns (bool success)，您可以向solidity编译器说两件事：

有一个名为success的变量bool（变量定义）
该变量成功将由函数返回（返回定义）

但是你的变量毕竟没有返回（你的函数以return true结束，这就是你在测试中得到InvalidResponse错误的原因。

对于您的代码，最有效的代码是：

function storeNum(uint mynum)
        public
        returns (bool)    // you should define at least the type
    {
     require(mynum > 10);
     mynumber = mynum; 
     return true;    
    }

作为练习，使用变量success：

的版本

function storeNum(uint mynum)
        public
        returns (bool success)
    {
     require(mynum > 10);
     mynumber = mynum; 
     success = true;    // don't need to use return
    }

希望它有所帮助。

Answer 2

好吧，我已经向Truffle github提交了一个问题，它仍然是打开的，也许这与最近的更改有关：

https://github.com/trufflesuite/truffle/issues/1001

目前的解决方法是将函数包装到void函数中，并测试执行是否成功：

/*
    Contract wrapper that inherits from MyContract. This contract wraps the calls of non void functions when
    testing for exceptions.

    Why not invoke directly the function?: https://github.com/trufflesuite/truffle/issues/1001
*/

contract MyExposedContract is MyContract() {


    function callStoreNum(uint256 num)  public {
        storeNum(num);
    }

}

然后在测试中使用该包装器

function testTheThrow() {
    MyExposedContract mycontract = new MyExposedContract (); 

    ThrowProxy throwproxy = new ThrowProxy(address(mycontract)); 
    uint num = 7;
    MyExposedContract (address(throwproxy)).callStoreNum(num);

    bool r = throwproxy.execute.gas(200000)(); 

    Assert.isFalse(r, "Should be false because it should throw!");

}

在Truffle中测试智能合约需要：如果功能无效，则会恢复交易

2 个答案: