Option actions are only invoked if the parent Command has an action

[jalfd]

If you set an Action on an Option object, it is not automatically invoked.
It is only invoked if the Command object also has an action.

The following reproduces the problem, as the first test fails, but the second one passes:

using System.CommandLine;
using System.CommandLine.Invocation;

namespace CommandLineTest
{
    [TestClass]
    public sealed class CommandLineTests
    {
        [TestMethod]
        public void OptionActionIsInvokedWithoutCommandAction()
        {
            bool actionWasInvoked = false;
            RootCommand root = new("CommandLine Test");

            Option<bool> option = new("--arg");
            option.Action = new CustomAction(_ =>
            {
                actionWasInvoked = true;
                return 0;
            });
            root.Options.Add(option);

            ParseResult parsedArgs = root.Parse(["--arg"]);
            int result = parsedArgs.Invoke();

            Assert.IsTrue(actionWasInvoked);
        }

        [TestMethod]
        public void OptionActionIsInvokedWithCommandAction()
        {
            bool actionWasInvoked = false;
            RootCommand root = new("CommandLine Test");

            Option<bool> option = new("--arg");
            option.Action = new CustomAction(_ =>
            {
                actionWasInvoked = true;
                return 0;
            });
            root.Options.Add(option);
            root.SetAction(r => { });

            ParseResult parsedArgs = root.Parse(["--arg"]);
            int result = parsedArgs.Invoke();

            Assert.IsTrue(actionWasInvoked);
        }

        class CustomAction : SynchronousCommandLineAction
        {
            private readonly Func<ParseResult, int> _callback;

            internal CustomAction(Func<ParseResult, int> callback) => _callback = callback;
            public override int Invoke(ParseResult parseResult) => _callback(parseResult);
            public override bool Terminating => false;
        }
    }
}