Add an Analyzer to Verify ParallelScope Usage

[JasonBock]

According to this doc, values of ParallelScope are only valid based on what member the Parallelizable is being used on. For example, ParalleScope.Children cannot be used on methods. Writing an analyzer to inform the developer of improper value usage would be a nice thing to have.

Edit by mikkelbu: Corrected link.

[mikkelbu]

See the documentation for more information.

From the code in ParallelizableAttribute.cs and the example below it seems that the validation is only for [Parallelizable(ParallelScope.Children)] and [Parallelizable(ParallelScope.Fixtures)] on test methods.

using NUnit.Framework;

// [assembly: Parallelizable(ParallelScope.Self)] // does not have an effect

namespace ParallelScopeTest
{
  [TestFixture]
  public class Class1
  {
    [Test]
    public void Test1()
    {
      Assert.Pass();
    }

    // [Parallelizable(ParallelScope.Children)] // Message: May not specify ParallelScope.Children on a non-parameterized test method
    [Test]
    public void Test2()
    {
      Assert.Pass();
    }

    // [Parallelizable(ParallelScope.Fixtures)] // Message: May not specify ParallelScope.Fixtures on a test method
    [Test]
    public void Test3()
    {
      Assert.Pass();
    }
  }
}