xUnit : Assert two List<T> are equal?
C#XunitC# Problem Overview
I'm new to TDD and xUnit so I want to test my method that looks something like:
List<T> DeleteElements<T>(this List<T> a, List<T> b);
Is there any Assert method that I can use ? I think something like this would be nice
List<int> values = new List<int>() { 1, 2, 3 };
List<int> expected = new List<int>() { 1 };
List<int> actual = values.DeleteElements(new List<int>() { 2, 3 });
Assert.Exact(expected, actual);
Is there something like this ?
C# Solutions
Solution 1 - C#
2021-Apr-01 update
I recommend using FluentAssertions. It has a vast IntelliSense-friendly assertion library for many use cases including collections
collection.Should().Equal(1, 2, 5, 8);
collection.Should().NotEqual(8, 2, 3, 5);
collection.Should().BeEquivalentTo(8, 2, 1, 5);
Original answer
xUnit.Net recognizes collections so you just need to do
Assert.Equal(expected, actual); // Order is important
You can see other available collection assertions in CollectionAsserts.cs
For NUnit library collection comparison methods are
CollectionAssert.AreEqual(IEnumerable, IEnumerable) // For sequences, order matters
and
CollectionAssert.AreEquivalent(IEnumerable, IEnumerable) // For sets, order doesn't matter
More details here: CollectionAssert
MbUnit also has collection assertions similar to NUnit: Assert.Collections.cs
Solution 2 - C#
In the current version of XUnit (1.5) you can just use
> Assert.Equal(expected, actual);
The above method will do an element by element comparison of the two lists. I'm not sure if this works for any prior version.
Solution 3 - C#
With xUnit, should you want to cherry pick properties of each element to test you can use Assert.Collection.
Assert.Collection(elements,
elem1 => Assert.Equal(expect1, elem1.SomeProperty),
elem2 => {
Assert.Equal(expect2, elem2.SomeProperty);
Assert.True(elem2.TrueProperty);
});
This tests the expected count and ensures that each action is verified.
Solution 4 - C#
Recently, I was using xUnit 2.4.0
and Moq 4.10.1
packages in my asp.net core 2.2 app.
In my case I managed to get it work with two steps process:
-
Defining an implementation of
IEqualityComparer<T>
-
Pass the comparer instance as a third parameter into
Assert.True
method:Assert.True(expected, actual, new MyEqualityComparer());
But there is another nicer way to get the same result using FluentAssertions package. It allows you to do the following:
// Assert
expected.Should().BeEquivalentTo(actual));
Interestingly that Assert.Equal()
always fails even when I ordered the elements of two lists to get them in the same order.
Solution 5 - C#
Just found the NotStrictEqual that seems to do it.