单元测试 – Moq是否取代标准的VS’Assert’测试？

让我们首先区分嘲笑和存根.存根纯粹用于隔离并将某种受控行为注入被测系统(SUT).

模拟是存根的超集,能够验证是否在模拟上调用了某些内容.在Moq中,调用Verify()会使stub成为关于该方法的模拟.调用VerifyAll()会使所有设置的方法都被模拟.

建议的方法是在测试中应该只有一个模拟.从这个意义上讲,它类似于Assert – 你不应该在测试中验证多个东西.

回到最初的问题.如果您正在执行状态测试,那么您将使用零个或多个存根和一个断言.如果您正在进行交互测试,那么您将使用零个或多个存根和一个模拟.下面是一个示例,其中可能适合使用mocks和asserts来测试相同的服务.

public interface IAccountRepository {
  decimal GetBalance(int accountId);
  void SetBalance(int accountId,decimal funds);
}

public class DepositTransaction {

  IAccountRepository m_repo;

  public DepositTransaction(IAccountRepository repo) {
    m_repo = repo;
  }

  public decimal DepositedFunds {get; private set;};

  void Deposit(int accountId,decimal funds) {
    decimal balance = m_repo.GetBalance(accountId);
    balance += funds;
    m_repo.SetBalance(balance);

    DepositedFunds += funds;
  }
}

public class DepositTest {
  [TestMethod]
  void DepositShouldSetBalance() {
    var accountMock = new Mock<IAccountRepository>();
    accountMock.Setup(a=>a.GetBalance(1)).Returns(100); //this is a stub with respect to GetBalance

    var transation = new DepositTransaction(accountMock.Object);
    transation.Deposit(1,20);

    accountMock.Verify(a=>a.SetBalance(1,120)); //this is a mock with respect to SetBalance
  }
  [TestMethod]
  void DepositShouldIncrementDepositedFunds() {
    var accountMock = new Mock<IAccountRepository>();
    accountMock.Setup(a=>a.GetBalance(1)).Returns(100); //this is a stub with respect to GetBalance

    var transation = new DepositTransaction(accountMock.Object);
    transation.Deposit(1,20);
    transation.Deposit(1,30);

    Assert.AreEqual(50,transaction.DepositedFunds);

  }
}