如果一个属性可以为空，则比较对象时 FluentAssertions 失败

Posted 2023-03-24

【中文标题】如果一个属性可以为空，则比较对象时 FluentAssertions 失败

【英文标题】：FluentAssertions fails when comparing objects if one property is nullable

【发布时间】：2013-11-11 21:43:36

【问题描述】：

场景：我有一个具有可为空属性的对象，当我运行被测方法时，该对象将被更新。在预期的对象中，我没有指定它，因为我想单独验证该值。这是一个简单的测试演示

using System;
using FluentAssertions;
using NUnit.Framework;

namespace FluentAssertionsNullableFailure

    public class SimpleWithNullable
    
        public Int64? nullableIntegerProperty
         get; set; 

        public string strProperty
         get; set; 
    

    [TestFixture]
    public class Demo
    
        public SimpleWithNullable actual = new SimpleWithNullable  nullableIntegerProperty = 1, strProperty = "I haz a string!" ;
        public SimpleWithNullable expected = new SimpleWithNullable  strProperty = "I haz a string!" ;

        [Test]
        public void NullableTest ()
        
            actual.ShouldBeEquivalentTo (
                expected,
                opt => opt.Using<Int64?> ( c => c.Subject.Should ().BeInRange ( 0, 10 ) ).WhenTypeIs<Int64?> ()
            );
        
    

但是，这会失败并显示以下消息：

Test Name:  NullableTest
Test FullName:  FluentAssertionsNullableFailure.Demo.NullableTest
Test Source:    c:\Users\ebelew\Documents\Visual Studio 2012\Projects\FluentAssertionsNullableFailure\FluentAssertionsNullableFailure\Demo.cs : line 25
Test Outcome:   Failed
Test Duration:  0:00:00.271

Result Message: 
Expected property nullableIntegerProperty to be <null>, but found 1.

With configuration:
- Select all declared properties
- Match property by name (or throw)
- Invoke Action<Nullable`1> when info.RuntimeType.IsSameOrInherits(System.Nullable`1[System.Int64])
- Invoke Action<DateTime> when info.RuntimeType.IsSameOrInherits(System.DateTime)
- Invoke Action<String> when info.RuntimeType.IsSameOrInherits(System.String)
Result StackTrace:  
at FluentAssertions.Execution.LateBoundTestFramework.Throw(String message) in d:\Workspace\Github\FluentAssertions\FluentAssertions.Net35\Execution\LateBoundTestFramework.cs:line 25
at FluentAssertions.Execution.CollectingAssertionStrategy.ThrowIfAny(IDictionary`2 context) in d:\Workspace\Github\FluentAssertions\FluentAssertions.Net35\Execution\CollectingAssertionStrategy.cs:line 57
at FluentAssertions.Execution.AssertionScope.Dispose() in d:\Workspace\Github\FluentAssertions\FluentAssertions.Net35\Execution\AssertionScope.cs:line 267
at FluentAssertions.Equivalency.EquivalencyValidator.AssertEquality(EquivalencyValidationContext context) in d:\Workspace\Github\FluentAssertions\FluentAssertions.Net35\Equivalency\EquivalencyValidator.cs:line 55
at FluentAssertions.AssertionExtensions.ShouldBeEquivalentTo[T](T subject, Object expectation, Func`2 config, String reason, Object[] reasonArgs) in d:\Workspace\Github\FluentAssertions\FluentAssertions.Net35\AssertionExtensions.cs:line 497
at FluentAssertionsNullableFailure.Demo.NullableTest() in c:\Users\ebelew\Documents\Visual Studio 2012\Projects\FluentAssertionsNullableFailure\FluentAssertionsNullableFailure\Demo.cs:line 25

如何使用 Options 上下文来执行此操作，而不是将其拆分为两个或多个断言。 （一个断言用于公共属性，每个用于具有范围或期望值而不是严格等价的项目）

注意：这在 expected 对象中没有显式值的引用类型上也会失败。

注意+：我试过 ExcludingMissingProperties()，它不会改变错误。

【参考方案1】：

您发现了一个我没有预见到的情况。我将在 2.2 版中修复它，但您可以通过 https://github.com/dennisdoomen/fluentassertions/issues/33 跟踪我的进度

【讨论】：

问题已解决。请查看 GitHub 上的问题以获取更多详细信息。