如何为 NSubstitute .Received 调用指定失败消息？答案

【问题标题】：How can I specify a failure message for an NSubstitute .Received call?如何为 NSubstitute .Received 调用指定失败消息？
【发布时间】：2014-10-20 14:59:48
【问题描述】：

在 NSubstitute 中，是否可以指定在 Received 失败时应该抛出的消息？类似于以下内容：

[Test]
public void Should_execute_command()
{
    var command = Substitute.For<ICommand>();
    var something = new SomethingThatNeedsACommand(command);

    something.DoSomething();

    command.Received()
        .Execute()
        .Because("We should have executed the command that was passed in");
}

为了比较，在起订量中，您可以这样做：

command.Verify(c => c.Execute, "We should have executed the command that was passed in");

然后您会在测试运行程序中将该消息作为测试失败消息的一部分。这有助于使测试失败更容易阅读/诊断。 NSubstitute 有类似的吗？

【问题讨论】：

标签： c# nsubstitute

【解决方案1】：

无法更改您在ReceivedCallException 中收到的消息；它是直接从 NSubstitute.Core.ReceivedCallsExceptionThrower Throw 方法中的硬编码字符串构建的：

public void Throw(ICallSpecification callSpecification, IEnumerable<ICall> matchingCalls, IEnumerable<ICall> nonMatchingCalls, Quantity requiredQuantity)
{
    StringBuilder stringBuilder = new StringBuilder();
    stringBuilder.AppendLine(string.Format("Expected to receive {0} matching:\n\t{1}", requiredQuantity.Describe("call", "calls"), callSpecification));
    this.AppendMatchingCalls(callSpecification, matchingCalls, stringBuilder);
    if (requiredQuantity.RequiresMoreThan<ICall>(matchingCalls))
    {
        this.AppendNonMatchingCalls(callSpecification, nonMatchingCalls, stringBuilder);
    }
    throw new ReceivedCallsException(stringBuilder.ToString());
}

除非您准备好深入研究 NSubstitute 代码，否则目前最好的选择是抓住 ReceivedCallsException 并抛出您自己的信息。

【讨论】：