xUnit Concurrency Problem with ITestOutputHelper

gistfile1.txt

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Xunit;
using Xunit.Abstractions;

namespace xBDD.Test.Features.RunTests
{
    public class xUnitTestOutputConcurrencyIssue
    {
        private readonly ITestOutputHelper outputWriter;

        public xUnitTestOutputConcurrencyIssue(ITestOutputHelper output)
        {
            this.outputWriter = output;
        }

        [Fact]
        public void ShouldBeAsync()
        {
            Task.Run(() => {
                System.Threading.Thread.Sleep(5);
                outputWriter.WriteLine("I am the async write!");
            });
        }
        [Fact]
        public void Sync1()
        {
            System.Threading.Thread.Sleep(5);
            outputWriter.WriteLine("I am the sync test.");
        }
        [Fact]
        public void Sync2()
        {
            System.Threading.Thread.Sleep(5);
            outputWriter.WriteLine("I am the sync test.");
        }
        [Fact]
        public void Sync3()
        {
            System.Threading.Thread.Sleep(5);
            outputWriter.WriteLine("I am the sync test.");
        }
        [Fact]
        public void Sync4()
        {
            System.Threading.Thread.Sleep(5);
            outputWriter.WriteLine("I am the sync test.");
        }
    }
}


Output:

    <collection total="5" passed="5" failed="0" skipped="0" name="Test collection for xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" time="0.024">
      <test name="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue.Sync3" type="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" method="Sync3" time="0.0061421" result="Pass">
        <output><![CDATA[I am the sync test.
]]></output>
      </test>
      <test name="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue.ShouldBeAsync" type="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" method="ShouldBeAsync" time="0.0002223" result="Pass" />
      <test name="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue.Sync4" type="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" method="Sync4" time="0.0055084" result="Pass">
        <output><![CDATA[I am the sync test.
]]></output>
      </test>
      <test name="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue.Sync2" type="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" method="Sync2" time="0.0058723" result="Pass">
        <output><![CDATA[I am the async write!
I am the sync test.
]]></output>
      </test>
      <test name="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue.Sync1" type="xBDD.Test.Features.RunTests.xUnitTestOutputConcurrencyIssue" method="Sync1" time="0.0058414" result="Pass">
        <output><![CDATA[I am the sync test.
]]></output>
      </test>
    </collection>