I am trying to add unit tests to my project. Some of these tests are checking if a list of objects does of does not contain an object. For checking if a list contains an object i've tried Assert.Contains(MyList, ExpectedObject), but it still gives an error that says that the list does not contain this object. Even when i debug the test i can see that the object is correctly added to the list.
The same happens with Assert.DoesNotContain(MyList, ExpectedObject). When i remove an item from the list and do this check it does say that it not in the list. But when i no longer remove the item, it still says that it is no longer in the list. Even though it is still in the list.
When i try it with a test list:List<string>. and do the same operations of adding and removing items, and then checking if these items are in the list or not. It does work.
Maybe Assert.Contains does not work for lists of objects. But the compiler does not give any errors. And i've also already checked if the ExpectedObject is the same type as the objects in the list.
Is there maybe another way of checking if an object is or isn't in a list. any help is appreciated.
In your test, is ExpectedObject the actual object in the list or an object with the same values? In C# two objects with the same property values are not actually equal. I suspect this is why your test is failing. Two strings with the same value are considered equal because the string object implements the Equals method (and some more), like @dorukerenaktas points out.
There's multiple ways to go about this. The easiest is by checking if an object with the expected property values is in the collection.
There's an overload of Assert.Contains that allows you to specify a predicate, for example:
Assert.Contains(MyList, item => item.Id == expectedId)
Another option is to override the Equals method on your object, like @dorukerenaktas explains, but I would only recommend that if it really makes sense for your class. I would definitely not do that just so you can use this in a test.