ProcessFiles/ProcessFilesTests/ProcessFilesTests.csproj

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>

    <IsPackable>false</IsPackable>
  </PropertyGroup>

  <ItemGroup>
    <None Remove="testFiles\subFolder\test2.txt" />
    <None Remove="testFiles\test1.txt" />
  </ItemGroup>

  <ItemGroup>
    <Content Include="testFiles\subFolder\test2.txt">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
    <Content Include="testFiles\test1.txt">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </Content>
  </ItemGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.2.0" />
    <PackageReference Include="xunit" Version="2.4.0" />
    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.0" />
    <PackageReference Include="coverlet.collector" Version="1.0.1" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\ProcessFiles\ProcessFiles.csproj" />
  </ItemGroup>

  <ItemGroup>
    <None Update="testFiles\subFolder\test3.txt">
      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
    </None>
  </ItemGroup>
</Project>