Assertion Equality Code Sample

EqualityTestShould.cs

using FluentAssertions;
using Xunit;

// To run this example you need to reference nuget packages: Xunit and FluentAssertions.

namespace EqualitySample
{
    public class EqualityTestShould
    {
        [Fact]
        public void Be_Equal_For_Value_Type()
        {
            int value1 = 1;
            int value2 = 1;

            Assert.Equal(value1, value2);
        }
        
        [Fact]
        public void Be_Equal_For_Array_Of_Value_Type()
        {
            int [] value1 = { 1, 2, 3 };
            int [] value2 = { 1, 2, 3 };

            Assert.Equal(value1, value2);
        }
        
        [Fact]
        public void Not_Be_Equal_For_Reference_Type()
        {
            Customer customer1 = new Customer { Id = 1, Name = "John" };
            Customer customer2 = new Customer { Id = 1, Name = "John" };

            Assert.NotEqual(customer1, customer2);
        }
        
        [Fact]
        public void Be_Equal_For_Same_Instance_Of_Reference_Type()
        {
            Customer john = new Customer { Id = 1, Name = "John" };
            
            Assert.Equal(john, john);
            Assert.Same(john, john);
        }

        [Fact]
        public void Be_Equal_For_Reference_Type_When_Equals_Is_Overriden()
        {
            CustomerBadExample customer1 = new CustomerBadExample { Id = 1, Name = "John" };
            CustomerBadExample customer2 = new CustomerBadExample { Id = 1, Name = "John" };

            Assert.Equal(customer1, customer2);
        }
        
        [Fact]
        public void Be_Equal_For_Reference_Type_When_Using_FluentAssertions()
        {
            Customer customer1 = new Customer { Id = 1, Name = "John" };
            Customer customer2 = new Customer { Id = 1, Name = "John" };

            customer1.ShouldBeEquivalentTo(customer2);
        }
        
        [Fact]
        public void Be_Equal_For_Array_Of_Reference_Type_When_Using_FluentAssertions()
        {
            var customers1 = new [] { new Customer { Id = 1, Name = "John" }, new Customer { Id = 2, Name = "Jack" } };
            var customers2 = new [] { new Customer { Id = 1, Name = "John" }, new Customer { Id = 2, Name = "Jack" } };

            customers1.ShouldBeEquivalentTo(customers2);
        }
    }
}

gistfile1.txt

namespace EqualitySample
{
    public class Customer
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }
}

gistfile2.txt

using System.Globalization;

namespace EqualitySample
{
    public class CustomerBadExample
    {
        public int Id { get; set; }
        public string Name { get; set; }

        public override bool Equals(object obj)
        {
            if (!(obj is CustomerBadExample))
                return false;

            var customer = obj as CustomerBadExample;
            return (this.Id == customer.Id &&
                    string.Compare(this.Name, customer.Name, true, CultureInfo.InvariantCulture) == 0);
        }
    }
}