Params overload for Contain and NotContain in GenericCollectionAssertions

[mu88]

Recently I had to write a couple of assertions which looked similar to this:

// Arrange
var car1 = new Car();
var car2 = new Car();
var car3 = new Car();
var car4 = new Car();
var cars = new List<Car> { car1, car2, car3, car4 };
var sut = new JunkYard();

// Act
sut.Scrap(cars, car2, car3); // removes car2 and car3 from cars

// Assert
cars.Should().Contain(new [] { car1, car4 });
cars.Should().NotContain(new [] { car2, car3 });

It would be great if I could write the Assert block like this:

cars.Should().Contain(car1, car4);
cars.Should().NotContain(car2, car3);

For this I'd need two overloads within GenericCollectionsAssertions:

• public AndConstraint<TAssertions> Contain(params T[] expected)
• public AndConstraint<TAssertions> NotContain(params T[] unexpected)

What do you think about this? If you like the idea, I'd love to provide a PR.

[jnyrup]

In 6.0.0 we removed some params overloads as they can bring in ambiguity.
I thought we had removed more, but it seems we kept [Not]ContainInOrder(params T[]) and Equal(params T[]) for GenericCollectionAssertions.

If Contain(params T[] expected) is added, the code below will not check if subject contains an element 1, but if it contains an element new[] { 1 }.

var subject = new List<object>();
subject.Should().Contain(new[] { 1 });

Related material:
https://fluentassertions.com/upgradingtov6#collections
The attached issues to #1529

[mu88]

Ah okay, I understand. That's sad but I'll hopefully get used to it 😉 From my perspective we can close this discussion

[jnyrup]

For your own project, you can of course add an extension method to GenericCollectionAssertions to get the params overload.

[mu88]

That's what I do at the moment. But since I faced the issue now a second time, I thought about providing it to the core. But then I'll think about my own NuGet package.