Custom magic command options seems to be empty in F#

[PawelStadnicki]

I have my own magic command created like this:

let command = new Command("#!mymagiccommand")
command.AddOption(new Option<string>("--load"))
command.AddOption(new Option<string>("--name"))
//this is not necessary, just to ensure typing
let d = System.Func<string, string, KernelInvocationContext, Task>(commandHandler)
command.Handler <-CommandHandler.Create(d)

Options seems to be registered correctly:
#!mymagicommand -h :

  #!mymagiccommand [options]

Options:
  --load <load>
  --name <name>    
  -?, -h, --help       Show help and usage information

However inside the command handler the option parameters seems to be empty

let commandHandler (load:string) (name:string) (context:KernelInvocationContext): Task = 
        context.Display (sprintf "load param is %s" load) |> ignore
        context.Display (sprintf $"name param is {name}") |> ignore

as

#!mymagiccommand --load loader --name name
or
#!mymagiccommand --load "loader" --name "name"
results with

load param is
name param is

Any clues ? Do I use it wrongly somehow or F# is not well supported in this case?

[jonsequitur]

This looks like you're hitting a common System.CommandLine gotcha. Your handler parameters will be bound based on the parameter names, so you need to have named parameters for your command handler method, e.g. load and name.

[PawelStadnicki]

How it should be different from commandHandler I already have?

let commandHandler (load:string) (name:string) (context:KernelInvocationContext): Task = ...

[PawelStadnicki]

Ok, I didn't notice earlier that System.Command is used. Found this issue which drove me to this working code:

type Opt(name, load, context) =
    member val Context:KernelInvocationContext = context
    member val Name: string = name
    member val Load: string = load 

[jonsequitur]

We have an alternative proposal for setting up handlers which doesn't use name-based matching, which you can see here: dotnet/command-line-api#1012

Feel free to weigh in.