FluentAssertions Should（）。BeEquivalentTo（）失败，其中包含从相同接口派生的运行时指定类型的列表

Question

我的以下测试说明了即时尝试要实现的简单示例（两个等效列表的比较）：

[Fact]
public void Test()
{
    // Arrange
    var list1 = new List<IDomainEvent> { new BusinessCreatedDomainEvent { Name = "Microsoft" } };
    var list2 = new List<IDomainEvent> { new BusinessCreatedDomainEvent { Name = "Microsoft" } };

    // Act

    // Assert
    list1.Should().BeEquivalentTo(list2);
}

理想情况下，每个列表应能够包含从IDomainEvent接口派生的任意数量的不同类型的项目。 测试当前失败。 我怀疑它与Should().BeEquivalentTo不适合比较运行时指定的类型。 如何配置此示例，以便测试通过？

当前测试结果为：

[8/14/2018 5:21:26 PM Error] [xUnit.net 00:00:00.7909767]     BusinessWrite.UnitTests.Infrastructure.EventStoreUnitTests.Test [FAIL]
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7922005]       System.InvalidOperationException : No members were found for comparison. Please specify some members to include in the comparison or choose a more meaningful assertion.
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7932461]       Stack Trace:
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7941986]         C:\projects\fluentassertions-vf06b\Src\FluentAssertions\Equivalency\GenericEnumerableEquivalencyStep.cs(74,0): at FluentAssertions.Equivalency.GenericEnumerableEquivalencyStep.Handle(IEquivalencyValidationContext context, IEquivalencyValidator parent, IEquivalencyAssertionOptions config)
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7945426]         C:\projects\fluentassertions-vf06b\Src\FluentAssertions\Equivalency\EquivalencyValidator.cs(85,0): at FluentAssertions.Equivalency.EquivalencyValidator.AssertEqualityUsing(IEquivalencyValidationContext context)
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7946187]         C:\projects\fluentassertions-vf06b\Src\FluentAssertions\Equivalency\EquivalencyValidator.cs(38,0): at FluentAssertions.Equivalency.EquivalencyValidator.AssertEquality(EquivalencyValidationContext context)
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7946610]         C:\projects\fluentassertions-vf06b\Src\FluentAssertions\Collections\CollectionAssertions.cs(394,0): at FluentAssertions.Collections.CollectionAssertions`2.BeEquivalentTo[TExpectation](IEnumerable`1 expectation, Func`2 config, String because, Object[] becauseArgs)
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7947629]         C:\projects\fluentassertions-vf06b\Src\FluentAssertions\Collections\CollectionAssertions.cs(331,0): at FluentAssertions.Collections.CollectionAssertions`2.BeEquivalentTo[TExpectation](IEnumerable`1 expectation, String because, Object[] becauseArgs)
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.7948569]         C:\Users\Christian\source\repos\unify\src\Services\Business\BusinessWrite\BusinessWrite.UnitTests\Infrastructure\EventStoreUnitTests.cs(43,0): at BusinessWrite.UnitTests.Infrastructure.EventStoreUnitTests.Test()
[8/14/2018 5:21:26 PM Informational] [xUnit.net 00:00:00.8058517]   Finished:    BusinessWrite.UnitTests

Answer 1

我怀疑IDomainEvent接口没有任何public属性。 这也解释了你所看到的例外，因为在逻辑BeEquivalentTo()使用的特性IDomainEvent的名单类型的List<IDomainEvent>

要使用BusinessCreatedDomainEvent的属性比较两个列表，可以改用

list1.Should().BeEquivalentTo(list2, options => options.RespectingRuntimeTypes());

从文档中

默认情况下，在递归比较中选择要处理的成员时，Fluent断言会尊重对象或成员的声明（编译时）类型。 也就是说，如果主题是OrderDto，但将其分配给的变量具有Dto类型，则在将对象与order变量进行比较时，仅考虑由后一类定义的成员。 可以配置此行为，并且您可以根据需要选择使用运行时类型：