c# - 如何创建自定义 FluentAssertion 错误消息？

Question

我有一个看起来像这样的测试:

using (new AssertionScope())
{
    foreach (var parameterType in parameterTypes)
    {
        var fooType = typeof(IFoo<>);
        var genericType = providerType.MakeGenericType(parameterType);

        serviceProvider
            .GetService(fooType)
            .Should()
            .NotBeNull($"all Foo types should be registered");
    }
}

测试失败导致此消息:

Expected serviceProvider.GetService(genericProviderType) not to be <null> because all Foo types should be registered.

但是，我希望消息说:

Expected IFoo<MyParameter> not to be <null> because all Foo types should be registered.

(我已经有一个方法来美化类型名 - type.GetPrettyName)

根据文档和源代码，看起来我需要找到一种方法来修改主题/标识符(不是 100% 确定)，但我找不到方法来做到这一点。

我还尝试在 AssertionScope 构造函数中使用 Lazy context 函数，但这会导致闭包被修改。

Answer 1

using (new AssertionScope())
{
    foreach (var parameterType in parameterTypes)
    {
        var fooType = typeof(IFoo<>);
        var genericType = providerType.MakeGenericType(parameterType);

        using _ = new AssertionScope(fooType.GetPrettyName());
       
        serviceProvider
            .GetService(fooType)
            .Should()
            .NotBeNull($"all Foo types should be registered");
    }
}