文章/答案/技术大牛

发布

社区首页 >问答首页 >FluentAssertions 6 ObjectGraph比较Enum和String

问FluentAssertions 6 ObjectGraph比较Enum和String
EN

Stack Overflow用户

提问于 2022-02-15 18:01:56

回答 2查看 523关注 0票数 0

使用FluentAssertions 6，您似乎可以在对象图中更长地验证Enum是否等同于字符串。来源：https://fluentassertions.com/upgradingtov6

enum MyEnum {
   A,
   B
}

class Source {
   MyEnum Enum { get;set;}
}

class Expectation {
   string Enum { get;set;}
}

var source = new Source() { Enum = MyEnum.A };
var expectation = new Expectation() {Enum = "A"};

//With V6 this assertion will fail but in V5 it will pass
expectation.Should().BeEquivalentTo(source, options => options.ComparingEnumsByName());

如何使用FluentAssertions断言上面的对象？我想要的行为是在枚举的ToString表示上进行断言。

正如我顺便指出的，当我将expectation与source交换时，我会得到不同的行为。它们不应该是等价物吗？

enums

fluent-assertions

回答 2

Stack Overflow用户

回答已采纳

发布于 2022-02-15 22:42:34

您可以定义一个更轻松的等效步长来处理字符串/枚举比较。

class RelaxedEnumEquivalencyStep : IEquivalencyStep
{
    public EquivalencyResult Handle(Comparands comparands, IEquivalencyValidationContext context, IEquivalencyValidator nestedValidator)
    {
        if (comparands.Subject is string subject && comparands.Expectation?.GetType().IsEnum == true)
        {
            AssertionScope.Current
                .ForCondition(subject == comparands.Expectation.ToString())
                .FailWith(() =>
                {
                    decimal? subjectsUnderlyingValue = ExtractDecimal(comparands.Subject);
                    decimal? expectationsUnderlyingValue = ExtractDecimal(comparands.Expectation);

                    string subjectsName = GetDisplayNameForEnumComparison(comparands.Subject, subjectsUnderlyingValue);
                    string expectationName = GetDisplayNameForEnumComparison(comparands.Expectation, expectationsUnderlyingValue);
                    return new FailReason(
                            $"Expected {{context:string}} to be equivalent to {expectationName}{{reason}}, but found {subjectsName}.");
                });

            return EquivalencyResult.AssertionCompleted;
        }

        if (comparands.Subject?.GetType().IsEnum == true && comparands.Expectation is string expectation)
        {
            AssertionScope.Current
                .ForCondition(comparands.Subject.ToString() == expectation)
                .FailWith(() =>
                {
                    decimal? subjectsUnderlyingValue = ExtractDecimal(comparands.Subject);
                    decimal? expectationsUnderlyingValue = ExtractDecimal(comparands.Expectation);

                    string subjectsName = GetDisplayNameForEnumComparison(comparands.Subject, subjectsUnderlyingValue);
                    string expectationName = GetDisplayNameForEnumComparison(comparands.Expectation, expectationsUnderlyingValue);
                    return new FailReason(
                            $"Expected {{context:enum}} to be equivalent to {expectationName}{{reason}}, but found {subjectsName}.");
                });

            return EquivalencyResult.AssertionCompleted;
        }

        return EquivalencyResult.ContinueWithNext;
    }

    private static string GetDisplayNameForEnumComparison(object o, decimal? v)
    {
        if (o is null)
        {
            return "<null>";
        }

        if (v is null)
        {
            return '\"' + o.ToString() + '\"';
        }

        string typePart = o.GetType().Name;
        string namePart = o.ToString().Replace(", ", "|", StringComparison.Ordinal);
        string valuePart = v.Value.ToString(CultureInfo.InvariantCulture);
        return $"{typePart}.{namePart} {{{{value: {valuePart}}}}}";
    }

    private static decimal? ExtractDecimal(object o)
    {
        return o?.GetType().IsEnum == true ? Convert.ToDecimal(o, CultureInfo.InvariantCulture) : null;
    }
}

如果只是为了一次测试

var source = new Source() { Enum = MyEnum.A };
var expectation = new Expectation() { Enum = "A" };

expectation.Should().BeEquivalentTo(source, options => options.Using(new RelaxedEnumEquivalencyStep()));

source.Should().BeEquivalentTo(expectation, options => options.Using(new RelaxedEnumEquivalencyStep()));

或者，如果需要全局设置，可以使用AssertionOptions.AssertEquivalencyUsing进行设置。

对于MSTest来说，把它放在AssemblyInitialize中。
对于Xunit，请参阅文档或使用此模块初始化程序示例。

AssertionOptions.AssertEquivalencyUsing(e => e.Using(new RelaxedEnumEquivalencyStep()));

var source = new Source() { Enum = MyEnum.A };
var expectation = new Expectation() { Enum = "A" };

expectation.Should().BeEquivalentTo(source);
source.Should().BeEquivalentTo(expectation);

为了完整起见，这里是MyEnum和string不匹配时失败消息的示例。

Expected property root.Enum to be equivalent to "B", but found MyEnum.A {value: 0}.
Expected property source.Enum to be <null>, but found MyEnum.B {value: 1}.
Expected property root.Enum to be equivalent to MyEnum.A {value: 0}, but found "B".
Expected property expectation.Enum to be equivalent to MyEnum.B {value: 1}, but found <null>.

票数 4

Stack Overflow用户

发布于 2022-02-15 18:56:27

您的期望将Enum属性定义为字符串，您提供的选项用于指导FA如何将期望的成员与主题进行比较。因此，在这种情况下，ComparingEnumsByName什么都不做，因为所涉及的属性是一个string。相反，您可以使用匿名类型作为期望。

票数 2

页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持

原文链接：

https://stackoverflow.com/questions/71131277

复制

相似问题

问FluentAssertions 6 ObjectGraph比较Enum和String
EN

回答 2

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问FluentAssertions 6 ObjectGraph比较Enum和StringEN

回答 2

Stack Overflow用户

Stack Overflow用户

社区

活动

圈层

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问FluentAssertions 6 ObjectGraph比较Enum和String
EN