測試松露中的智能合約要求：如果功能不無效，則交易將被還原

Question

我正在根據本文嘗試僅通過可靠性來測試智能合約的要求：

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

這是合同，委托代理合同和測試：

/* 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);
  }
}

如果我運行測試，則會收到此錯誤：

如果我將storeNum函數更改為從

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

至

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

測試工作..

有任何想法嗎？

我正在使用松露v4.1.11

Answer 1

讓我們看看您的代碼：

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

通過定義returns (bool success)您對Solidity編譯器說了兩件事：

• 有一個名為bool類型的success變量（變量定義）。
• 該變量成功將由函數返回（返回定義）

但是您的變量畢竟不會返回（您的函數以return true結尾，這就是為什么您在測試中收到InvalidResponse錯誤的原因。

對於您的代碼，最有效的代碼是：

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

作為練習，使用變量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
    }

希望能幫助到你。

Answer 2

好吧，我已經向Truffle github提交了一個問題，它仍然是打開的，也許這與最近的更改有關：

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

現在的一種解決方法是將函數包裝到void函數中，並測試執行是否成功：

/*
    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);
    }

}

然后在測試中使用該包裝器：

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!");

}