Lazy initial values for options

[johngeorgewright]

I'm in a scenario where I'd like to asynchronously provide default values only when a value isn't provided. As this isn't an option in clipanion, I am working with a fork of the project. Is this something you'd consider as part of the library?

An example:

class MyCommand extends Command {
  foo = Option.String(
    '-f,--foo',
    async () => {
      // The value wasn't provided.
      // Fetch something asynchronously?
      // Maybe prompt the user for extra information?
    }
  )
}

I understand this can be achieved by adding logic in Command.prototype.execute...

  override async execute() {
    const foo = await handleFooOption(this.foo)
    const other = await handleOtherOption(this.other)
    // ...
  }

However, the above isn't very scaleable as the project grows.