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moq-verify方法签名可以看到调用,但不匹配?

moq unit-testing c#

Jeremy Holovacs · 技术社区 · 6 年前

我有一个这样的界面:

public interface IStatisticsCollector : IDisposable
{
    Task Measure(string metricName, decimal value, IDictionary<string, string> tags = null);
}

我正在注射这个 IStatisticsCollector 到我的课堂上,像这样使用它:

var stopwatch = new Stopwatch();
await dataCollector.Measure("rbk_init", stopwatch.ElapsedMilliseconds);
...
await dataCollector.Measure("rbk_compiled", stopwatch.ElapsedMilliseconds);
...

设置我的单元测试以验证我是否记录了我想要的所有统计点,我模拟了 IStatisticsCollector(IStatisticsCollector) :

private readonly Mock<IStatisticsCollector> _statisticsCollector = new Mock<IStatisticsCollector>();
_statisticsCollector.Setup(x => x.Measure(It.IsAny<string>(), It.IsAny<long>(), It.IsAny<IDictionary<string, string>>())).Verifiable();

当我运行单元测试时,我的验证在这条线上失败:

//assert
_statisticsCollector.Verify(
    x => x.Measure(It.IsAny<string>(), It.IsAny<long>(), It.IsAny<IDictionary<string, string>>()), Times.Exactly(5));

…显示以下消息:

Moq.MockException : 
Expected invocation on the mock exactly 5 times, but was 0 times: x => x.Measure(It.IsAny<string>(), (decimal)It.IsAny<long>(), It.IsAny<IDictionary<string, string>>())

Configured setups: 
IStatisticsCollector x => x.Measure(It.IsAny<string>(), (decimal)It.IsAny<long>(), It.IsAny<IDictionary<string, string>>())

Performed invocations: 
IStatisticsCollector.Measure("rbk_init", 31, null)
IStatisticsCollector.Measure("rbk_compiled", 35, null)
IStatisticsCollector.Measure("rbk_stored", 36, null)
IStatisticsCollector.Measure("rbk_db_updated", 352, null)
IStatisticsCollector.Measure("rbk_completed", 361, null)
   at Moq.Mock.VerifyCalls(Mock targetMock, InvocationShape expectation, LambdaExpression expression, Times times, String failMessage) in C:\projects\moq4\src\Moq\Mock.cs:line 378

……这很奇怪,因为看起来它捕获了5个匹配的调用,但显然没有将它们中的任何一个视为实际匹配。现在我假设这可能与秒表 ElapsedMilliseconds 是长的,但接口需要十进制(隐式强制转换),因此我更改了verify以查找 It.IsAny<decimal>() 但这给了我一个意想不到的结果:

Moq.MockException : 
Expected invocation on the mock exactly 5 times, but was 1 times: x => x.Measure(It.IsAny<string>(), It.IsAny<decimal>(), It.IsAny<IDictionary<string, string>>())

Configured setups: 
IStatisticsCollector x => x.Measure(It.IsAny<string>(), It.IsAny<decimal>(), It.IsAny<IDictionary<string, string>>())

Performed invocations: 
IStatisticsCollector.Measure("rbk_init", 28, null)
   at Moq.Mock.VerifyCalls(Mock targetMock, InvocationShape expectation, LambdaExpression expression, Times times, String failMessage) in C:\projects\moq4\src\Moq\Mock.cs:line 378

找到了一个…只有一个。似乎没有例外,所以我不知道为什么只有一个例外。

我还注意到可选参数上的空值,并尝试根据空值而不是 IDictionary<string, string> 但这同样没有结果。

有人能解释这种行为吗?我需要做什么来修复我的测试?

1 回复 | 直到 6 年前

Ricardo Alves 6 年前

此行将始终失败:

_statisticsCollector.Verify(
    x => x.Measure(It.IsAny<string>(), It.IsAny<long>(), It.IsAny<IDictionary<string, string>>()), Times.Exactly(5));

这是因为您对mock说它需要在第二个参数中接收一个long,但是接口说在第二个参数中它将接收一个decimal:

public interface IStatisticsCollector : IDisposable
{
    Task Measure(string metricName, decimal value, IDictionary<string, string> tags = null);
}

因为小数不能太长,所以您的验证将始终失败。