Generic comparison logic for objects

Question

I am working on the back end of a REST API -
For a POST request (in one of the scenarios) I need to validate if the object sent by the user is the same as the one stored in the Db.

What is an efficient way of comparing two objects in C#?

PS - I want the comparison logic to withstand the test of time, i.e. being a huge team I do not rely on people adding new fields in the IComparable logic. Anyone can add a new property to the object and that would skip the validation test if they do not add that to the comparison logic.

I am thinking of Deserializing the object stored in our database and compare it to the deserialized version of that the user POSTS.

Any thoughts?

Does the object have any properties which uniquely identify each instance? Something like a primary key in a database? Or are there any properties which must be unique? — John Saunders, May 23 '15 at 06:02
It helps because you only need to compare the properties which are part of the primary key in order to determine uniqueness. — John Saunders, May 23 '15 at 06:53
Aah well, I didn't explain myself clearly then. Let us say for one scenario, i want to make a validation that throws if you try to update any property in the object. Since this is a POST call, I do not want to call into the update sproc if any property has been modified while my object happens to be in a terminal state. So, it's not just the primary key. — divyanshm, May 23 '15 at 06:55
From the API perspective, I want to let the user know that he cannot modify a sub resource as it is in a terminal state. — divyanshm, May 23 '15 at 06:56

score 0 · Accepted Answer · edited May 23 '17 at 10:26

Automagically implement IComparable<T> on T for ValueObjects (objects for which their identity is all of their fields) is a form of Aspect-Oriented Programming (AOP).

There are various Aspect frameworks for C#.

In this case I would advise you use PM> Install-Package Equals.Fody.

To use it is pretty easy.

[Equals]
public class Foo
{
    public int X { get; set; }
    public int Y { get; set; }        
}

Generic comparison logic for objects

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