Return values from actions on Options? #2768

Activity

1. jonsequitur commented on Feb 2, 2026

   

   jonsequitur

   on Feb 2, 2026

   Last edited by jonsequitur

   Contributor

   More actions

   Typically people put the main action of the app inside a command handler, in which case the flow of the application will be to terminate after --help is invoked. That top-level code flow looks something like this:

   var rootCommand = new RootCommand
     {
       // options & arguments
     };
   rootCommand.SetAction((parseResult, cancellationToken) => /* 
     main application flow is started
   */);
   
   return rootCommand.Parse(args).InvokeAsync();

   HelpOption is present on RootCommand by default and it has its own handler.

   what is the point of setting actions on an Option object? (And what is the point of being able to return an integer from those actions?)

   SetAction is just syntactic sugar which creates and assigns an (internal) AnonymousSynchronousCommandLineAction or AnonymousAsynchronousCommandLineAction to a command. It was left off for Option because it was considered to be relatively less common scenario than setting handlers on Command.

   what is the intended way to detect that --help was invoked so you can terminate the application?

   You can look up results by name once you have a ParseResult:

   var helpWasRequested = parseResult.GetResult("--help") is not null;
2. jalfd commented on Feb 4, 2026

   

   jalfd

   on Feb 4, 2026

   Author

   More actions

   Thank you for the explanation!

   So am I correct that return values from actions on options are discarded? You can attach an action (but as you say it is uncommon to do so, and it doesn't have the same syntactic sugar), but if you do, its return value is silently discarded? That seems like something that should be mentioned in the documentation :)

   As an aside, it seems like actions on options are only invoked if you also set an action on the Command object. Is that intentional or a bug?
3. jonsequitur commented on Feb 4, 2026

   

   jonsequitur

   on Feb 4, 2026

   Contributor

   More actions

   These sounds like bugs. Can you provide a simple code example that reproduces the issue?

   👍React with 👍1Reacted by Jesper Alf Dam
4. jalfd commented on Feb 13, 2026

   

   jalfd

   on Feb 13, 2026

   Author

   More actions

   Done, see #2771 and #2772 :)