In order to troubleshoot tests, or stay focused when working on only a portion of the code base, you can simply mark a test or group as focused eg. forced.

1. Mark specific test cases as focused

You can mark test cases with the FIt syntax. That will ensure only those tests will run:

using System;

using static Xenial.Tasty;

namespace FocusedTests
{
    class Program
    {
        static void Main(string[] args)
        {
            //If there are tests marked in the tree as focused/forced, other ones will not run
            Describe(nameof(FocusedTests), () =>
            {
                It("Should not run #1", () => false);
                FIt("Should run #1", () => true); //Mark the test as focused
                FIt("Should run #2", () => true); //You can mark multiples in focus/force mode
                It("Should not run #2", () => false); //This test will also not run
            });

            Run(args);
        }
    }
}

Let's run:

dotnet run

👍 [00:00:00.0042]  FocusedTests Should run #1
👍 [00:00:00.0000]  FocusedTests Should run #2

=================================================================================================
Summary:              F0 |              I0 |             NR2 |              S2 | T4
Time:    [00:00:00.0000] | [00:00:00.0000] | [00:00:00.0000] | [00:00:00.0043] | [00:00:00.0043]
Outcome:         Success
=================================================================================================

As you can see, only the tests that are in focused mode were run. It didn't even output anything from the other tests, to reduce visual clutter, because you are in focus mode and don't care about the other tests at the moment.

2. Mark test groups as focused

If you have a collection of tests that you want to focus on, you also can mark test groups as focused with FDescribe. That will mark all child groups and tests in this group to be in focus mode:

using System;

using static Xenial.Tasty;

namespace FocusedTests
{
    class Program
    {
        static void Main(string[] args)
        {
            Describe(nameof(FocusedTests), () =>
            {
                It("Should not run #1", () => false);
                FIt("Should run #1", () => true);
                FIt("Should run #2", () => true);
                It("Should not run #2", () => false);

                FDescribe("all those tests and groups are in focus mode", () =>
                {
                    It("Focused #1", () => true);

                    Describe("even if nested", () =>
                    {
                        It("Focused #2", () => true);
                        It("Focused #3", () => true);
                    });
                });
            });

            Run(args);
        }
    }
}

Let's run:

dotnet run

👍 [00:00:00.0042]  FocusedTests Should run #1
👍 [00:00:00.0001]  FocusedTests Should run #2
👍 [00:00:00.0001]  FocusedTests all those tests and groups are in focus mode Focused #1
👍 [00:00:00.0000]  FocusedTests all those tests and groups are in focus mode even if nested Focused #2
👍 [00:00:00.0000]  FocusedTests all those tests and groups are in focus mode even if nested Focused #3

=================================================================================================
Summary:              F0 |              I0 |             NR2 |              S5 | T7
Time:    [00:00:00.0000] | [00:00:00.0000] | [00:00:00.0000] | [00:00:00.0046] | [00:00:00.0046]
Outcome:         Success
=================================================================================================

3. Congratulations

You wrote your very first delicious focused tests! Next you will learn how to get rapid feedback with watch mode.