NSubstitute 不打印出 NUnit 断言

Question

我刚刚开始使用NSubstitute。我主要与Moq 合作，这就是我正在做的事情：

// In my unit test on menter code herey mock:
HasLogMessage(Is.EqualTo("expected value"));

private void HasLogMessage(EqualConstraint s)
{
    log.Verify(y => y.Error(It.Is<string>(v => Verify(v, s))));
}

private bool Verify(string s, EqualConstraint equalConstraint)
{
    Assert.That(s, equalConstraint);
    return true;
}

运行单元测试时的输出。请注意，它说明了预期值和实际值：

Expected string length 14 but was 116. Strings differ at index 0.
Expected: "expected value"
But was:  "real value..."
-----------^
 at NUnit.Framework.Assert.That(Object actual, 

IResolveConstraint 表达式，字符串消息，Object[] args)

我希望能够将它与 NSubstitute 模拟一起使用，这是我的尝试：

HasLogMessage(Is.EqualTo("Expected value"));

private void HasLogMessage(EqualConstraint s)
{
    log.Received().Log(LogLevel.Error, Arg.Is<Func<string>>(x => Verify(x, 
}

private bool Verify(Func<string> s, EqualConstraint equalConstraint)
{
    Assert.That(s(), equalConstraint);
    return true;
}

但这不会输出NUnit断言错误

NSubstitute.Exceptions.ReceivedCallsException : Expected to receive a call matching:
    Log(Error, x => value(IdentityServer3.Saml2Bearer.Tests.Saml2BearerGrantValidatorTest)
.Verify(x, value(IdentityServer3.Saml2Bearer.Tests.Saml2BearerGrantValidatorTest+<>c__DisplayClass21_0).s), <null>, )
Actually received no matching calls.
Received 2 non-matching calls (non-matching arguments indicated 
with '*' characters)

我错过了什么吗？

Answer 1

日志类型澄清后更新：

除了使用incomplete plumbing mentioned below，对于Func<string>，我会捕获使用的参数并稍后检查它们。

var log = Substitute.For<ILog>();
var loggedErrors = new List<string>();
// Capture the argument passed to Log whenever LogLevel.Error is called
log.Log (LogLevel.Error, Arg.Do<Func<string>>(x => loggedErrors.Add(x())));

log.Log(LogLevel.Error, () => "the real call...");

Assert.That(loggedErrors, Is.EqualTo (new[] { "expected" }));

/*
NUnit.Framework.AssertionException:   Expected is <System.String[1]>, actual is <System.Collections.Generic.List`1[System.String]> with 1 elements
  Values differ at index [0]
  Expected string length 8 but was 16. Strings differ at index 0.
  Expected: "expected"
  But was:  "the real call..."
  -----------^
*/

原答案：

我们通常把它写成一个普通的Received() 断言，它将显示预期值和实际值。

log.Received ().Log (LogLevel.Error, "expected");

/*
Expected to receive a call matching:
    Log(Error, "expected")
Actually received no matching calls.
Received 1 non-matching call (non-matching arguments indicated with '*' characters):
    Log(Error, *"the real call..."*)
*/

如果您想使用断言库进行更具描述性的匹配，则 NSubstitute 中存在一些不完整的管道，以便通过一些工作来实现这一点。有an example in this issue。