An example xUnit test where dispose is not called when running multiple tests at once.

BannerTests.cs

using ApprovalTests;
using ApprovalTests.Namers;
using ApprovalTests.Reporters;
using ApprovalTests.Reporters.TestFrameworks;
using Moq;
using RazorGenerator.Testing;
using Umbraco.Core.Composing;
using Xunit;
using Xunit.Abstractions;

namespace Website.Tests
{
    [UseReporter(typeof(XUnit2Reporter))]
    public class BannerTests : TestBase
    {
        private static BannersController controller;
        private static ASP._Views_Partials_Banners_HomepageBannerListing_cshtml homepageBannersView;

        public BannerTests(ITestOutputHelper output)
            : base(output)
        {
            Current.Factory = new Mock<IFactory>().Object;

            homepageBannersView = new ASP._Views_Partials_Banners_HomepageBannerListing_cshtml();
        }

        public override void Dispose()
        {
            Current.Reset();
        }

        [Fact]
        [UseApprovalSubdirectory("ApprovedHtml")]
        public void VerifyHomepageListingHandlesNullBanners()
        {
            var renderedView = homepageBannersView.Render(null);

            Approvals.VerifyHtml(renderedView);
        }
    }
}