C# 测试 - 比较自定义类型列表

Question

我正在尝试编写测试检查 JSON 转换器是否正确地将输入反序列化到我的自定义列表

    [TestMethod]
    public void JSONInput_Changed()
    {
        List<PointOnChart> _expectedPointsOnChart;
        _expectedPointsOnChart = new List<PointOnChart>();
        _expectedPointsOnChart.Add(new PointOnChart { Timestamp = "2020-02-14T09:00:00.000Z", Value1 = 10, Value2 = 20, Value3 = 30 });
        _expectedPointsOnChart.Add(new PointOnChart { Timestamp = "2020-02-14T09:01:00.000Z", Value1 = 11, Value2 = 21, Value3 = 31 });
        _expectedPointsOnChart.Add(new PointOnChart { Timestamp = "2020-02-14T09:02:00.000Z", Value1 = 12, Value2 = 22, Value3 = 32 });
        _expectedPointsOnChart.Add(new PointOnChart { Timestamp = "2020-02-14T09:03:00.000Z", Value1 = 13, Value2 = 23, Value3 = 33 });

        MultipleBarChart multipleBarChartTest = new MultipleBarChart();
        multipleBarChartTest.MeInitialize(DateTimeIntervalType.Minutes);
        string JSONstring = System.IO.File.ReadAllText(@"C:\Users\slawomirk\source\repos\VIXCharts\iFixMultipleBarChartTests\TestJson.txt");
        multipleBarChartTest.JSONInput = JSONstring;
        List<PointOnChart> resultPointsOnChart = multipleBarChartTest.PointsOnChart;

        //bool areEqual = _expectedPointsOnChart.SequenceEqual(resultPointsOnChart);
        IEnumerable<PointOnChart> resultList;
        resultList = _expectedPointsOnChart.Except(resultPointsOnChart);
        if (resultList.Any())
        {
            Assert.Fail();
        }
    }

列表包含此类的对象

public class PointOnChart
{
    public string Timestamp { get; set; }
    public double Value1 { get; set; }
    public double Value2 { get; set; }
    public double Value3 { get; set; }
}

这是我正在阅读以反序列化的文件：

[{"Timestamp":"2020-02-14T09:00:00.000Z","Value1":10,"Value2":20,"Value3":30},{"Timestamp":"2020-02-14T09: 01:00.000Z","Value1":11,"Value2":21,"Value3":31}, {"Timestamp":"2020-02-14T09:02:00.000Z","Value1":12," Value2":22,"Value3":32}, {"Timestamp":"2020-02-14T09:03:00.000Z","Value1":13,"Value2":23,"Value3":33}]

我尝试了多种方法来比较两个列表，但都失败了，例如：- Fluent Assertion - CollectionAssert

当我在调试中检查两个 List 时，它们是相同的。 我知道这可能是微不足道的，但我可以在网上找到任何解决方案，提前致谢。

Answer 1

您应该为PointOnChart类实现Equals方法，如下所示：

public override bool Equals(object other)
{
    if (object.ReferenceEquals(other, this)) return true;

    var obj = other as PointOnChart;

    if (obj == null) return false;

    return this.Timestamp == obj.Timestamp && this.Value1 == obj.Value1 && this.Value2 == obj.Value2 && this.Value3 == obj.Value3;
}

这样SequenceEquals扩展方法将正常运行。

Answer 2

与其使用Equals覆盖污染您的生产代码，不如考虑使用 www.fluentassertions.com 并将该语句写为：

resultPointsOnChart.Should().BeEquivalentTo(expectedPointsOnChart);

Answer 3

除了其他答案之外，我建议实现IEquatable<T>以及像这样覆盖GetHashCode()和Equals(Object) 。

public class PointOnChart : IEquatable<PointOnChart> {

    public string Timestamp { get; set; }
    public double Value1 { get; set; }
    public double Value2 { get; set; }
    public double Value3 { get; set; }

    public override Int32 GetHashCode() => Timestamp.GetHashCode() ^ Value1.GetHashCode() ^ Value2.GetHashCode() ^ Value3.GetHashCode();

    public override Boolean Equals(Object obj) => Equals(obj as PointOnChart);

    public Boolean Equals(PointOnChart other) => other != null && other.Timestamp == Timestamp && other.Value1.Equals(Value1) && other.Value2.Equals(Value2) && other.Value3.Equals(Value3);

}

这将为您提供所需的所有比较。 如果您以后需要，还可以更轻松地实现IEqualityComparer或IEqualityComparer<T> 。