DefinitionOrderer.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Xunit.Abstractions;
using Xunit.Sdk;

namespace DotNetMVCTest
{
    public class DefinitionOrderer : ITestCaseOrderer
    {
        public IEnumerable<TTestCase> OrderTestCases<TTestCase>(IEnumerable<TTestCase> testCases)
            where TTestCase : ITestCase
        {
            return testCases.ToList();
        }
    }
}

SampleTests.cs

using Xunit;

[TestCaseOrderer("DotNetMVCTest.DefinitionOrderer", "DotNetMVC")
public class SampleTests
{
    [Fact]
    public void Test1()
    {
        Assert.True(false);
    }
    
    [Fact]
    public void Test2()
    {
        Assert.True(false);
    }
}