如何在 FluentAssertions 的集合断言中重用自定义对象断言

Question

我已经阅读了FluenAssertions Extensibility 页面，但我仍然无法理解如何为对象集合创建一个Should().BeEquivalentTo() 比较方法，如果我已经为一个对象实现了Should().BeEquivalentTo()，同时保留了所有其他断言方法同一个集合。

这是一个简化的例子： 我要检查的类：

public class CalculationResult
{
    public DateTime Date { get; set; }
    public int Id { get; set; }
    public bool CalcState { get; set; }
    public double Result { get; set; }
}

我在 Specflow 测试套件中转换表格行的类

public class CalcResultBdd
{
    public DateTime Date { get; set; }
    public double Result { get; set; }
}

类到类比较类是：

public class CalculationResultAssertions : ReferenceTypeAssertions<CalculationResult, CalculationResultAssertions>
{
    public CalculationResultAssertions(CalculationResult instance)
    {
        Subject = instance;
    }

    protected override string Identifier => "CalculationResult";

    [CustomAssertion]
    public AndConstraint<CalculationResultAssertions> BeEquivalentTo(
        CalcResultBdd expectedResult,
        double precision = 0.001,
        string because = "",
        params object[] becauseArgs)
    {
        Execute.Assertion.
            BecauseOf(because, becauseArgs).
                ForCondition(expectedResult != null).
                FailWith("You cannot assert that calculation result is correct if you do not pass a proper object").
            Then.
                ForCondition(precision >= 0).
                FailWith("You cannot compare double values if you provide negative precision").
            Then.
            Given(() => Subject).
                ForCondition(s => s.CalcState).
                FailWith("Expected CalcState to be \"true\"").
            Then.
                ForCondition(s => s.Date == expectedResult.Date).
                FailWith(
                    "Expected Date to be {0}{reason}, but found {1}",
                    _ => expectedResult.Date.ToString("yyyy-MM-dd"),
                    s => s.Date.ToString("yyyy-MM-dd")).
            Then.
                ForCondition(s => Math.Abs(s.Result - expectedResult.Result) <= precision).
                FailWith(
                    "Expected Result to be {0} with precision {1}{reason}, but found {2}",
                    _ => expectedResult.Result,
                    _ => precision,
                    s => s.Result);

        return new AndConstraint<CalculationResultAssertions>(this);
    }
}

连接 FluentAssertions 和自定义断言类的静态类：

public static class AssertionExtensions
{
    public static CalculationResultAssertions Should(this CalculationResult instance)
    {
        return new CalculationResultAssertions(instance);
    }
}

如果我运行以下命令，但没有为 List<CalculationResult> 重新定义 BeEquivalentTo

List<CalculationResult> actualResults = /* getting results here */
actualResults.Should().BeEquivalentTo(new CalcResultBdd[] { /* expected results here */ })

FluentAssertions 将使用内置结构比较而不是自定义比较。我是否可以更改我的代码中的某些内容，以便 Fluent 断言使用自定义比较来代替？

Answer 1

如果我没记错的话，BeEquivalentTo 扩展方法期望是通用的，也会取代你的。