如何使用流畅的断言比较对象图中的嵌套列表

Question

如果我有一个包含列表的预期对象图，如下所示：

        var expectedExperiment = new Experiment
        {
            Number= "12345",
            AllocatedInstrument = "Instrument 1",
            Experimenters = new List<Experimenter>
            {
                new Experimenter
                {
                    Name = "Sue"
                    Role = "Scientist",
                    Id = 1,
                    Initials = "S"
                },
                new Experimenter()
                {
                    Name = "Mark",
                    Role = "Technician",
                    Id = 2,
                    Initials = "M"
                },
            }
        };

当我只想在子对象列表中包含某些属性时，如何将它与我的实际对象进行比较。

例如，我想写这样的东西来比较所有父对象属性和一些子对象属性：

        actualExperiment.ShouldBeEquivalentTo(expectedExperiment, options => options
            .Including(o => o.Number)
            .Including(o => o.AllocatedInstrument)
            .Including(o => o.Experimenters.Select(e => e.Role))
            .Including(o => o.Experimenters.Select(e => e.Name)));

但我得到一个例外：

System.ArgumentException : Expression <o.Experimenters.Select(e => e.Role)> cannot be used to select a member.

在这种情况下，我不介意子项的顺序，但我想断言我关心的属性符合预期。

Answer 1

您可以通过检查运行-时间类型和当前对象的选定成员路径来做到这一点：

.Including(subjectInfo => subjectInfo.RuntimeType == typeof(Experimenter) &&
                          subjectInfo.SelectedMemberPath.EndsWith("Role"))

这可以提取到一个方法中以供进一步重用：

private Expression<Func<ISubjectInfo, bool>> BuildMemberExpression<TSource, TProperty>(Expression<Func<TSource,TProperty>> propertySelector)
    {
        var memberExpression = propertySelector.Body as MemberExpression;
        if (memberExpression == null)
        {
            throw new NotSupportedException();
        }

        return subjectInfo => subjectInfo.RuntimeType == typeof(TSource) && 
                              subjectInfo.SelectedMemberPath.EndsWith(memberExpression.Member.Name);
    }

现在这样使用：

.Including(BuildMemberExpression((Experimenter e) => e.Name))
.Including(BuildMemberExpression((Experimenter e) => e.Role))

如何使用流畅的断言比较对象图中的嵌套列表

How to compare nested lists in object graphs using fluent assertions

c#

testing

nunit

fluent-assertions