Compare two objects with more than one list property

[huangyy21]

Hi, Form example4, I have known how to compare objects with one list. But if my object have more than one list, what should I do?

[huangyy21]

I just tried to implement custom Comparer for every list property and it works. Is there any better way?

[ValeraT1982]

Are types of the lists same? Can you give an example?

[huangyy21]

No, the types are different, but all have an id property. For example, the demo class below.

public class Demo
{
    public string Name { get; set; }

    public List<A> ItemA { get; set; }

    public List<B> ItemB { get; set; }
}

public class A
{
    public int Id { get; set; }

    public string AA { get; set; }
}

public class B
{
    public int Id { get; set; }

    public int BB { get; set; }
}

[huangyy21]

I create a class to implement custom Comparer making use of generics, and only have to add if statement in ComparersFactory for every type of lists.

[ValeraT1982]

@huangyy21 you can inherit both classes from the same interface and use this interface in ComparersFactory instead of having separate if for each class.

[reponemec]

In my PR #47, you don't need to implement custom comparer at all. All you need to do is this:

var settings = new ComparisonSettings();
settings.ConfigureListComparison(compareElementsByKey: true, compareUnequalLists: true);
var comparer = new Comparer<Formula>(settings);
var isEqual = comparer.Compare(formula1, formula2, out var differences);

The complete test method: https://github.com/reponemec/ObjectsComparer/blob/35cd3fc60898ff44639146efe4efb9a108a5a5f7/ObjectsComparer/ObjectsComparer.Examples/Example4/Example4Tests_BuiltInKeyComparison.cs#L119

[huangyy21]

In my PR #47, you don't need to implement custom comparer at all. All you need to do is this:

var settings = new ComparisonSettings();
settings.ConfigureListComparison(compareElementsByKey: true, compareUnequalLists: true);
var comparer = new Comparer<Formula>(settings);
var isEqual = comparer.Compare(formula1, formula2, out var differences);

The complete test method: https://github.com/reponemec/ObjectsComparer/blob/35cd3fc60898ff44639146efe4efb9a108a5a5f7/ObjectsComparer/ObjectsComparer.Examples/Example4/Example4Tests_BuiltInKeyComparison.cs#L119

Thanks for reply. My memberPath needs more information, so it may be better to implement custom comparer.

[reponemec]

My memberPath needs more information, so it may be better to implement custom comparer.

Absolutely, however the memberPath property can also be customized using ComparisonSettings: https://github.com/reponemec/ObjectsComparer/blob/35cd3fc60898ff44639146efe4efb9a108a5a5f7/ObjectsComparer/ObjectsComparer.Tests/DifferenceConfigurationTests.cs#L98