Adding 'choices' within the option decorator

[jmcdo29]

Discussed in #326

^{Originally posted by BenSawary March 18, 2022}
I'd like to define a valid list of a commands option argument. Since commander 7, (tj/commander.js#518) it is possible to create an option with choices. Is it possible to add this functionality also in the nest-commander option decorator?

@option({
flags: '--option [option]',
choices: ['a', 'b', 'c'],
defaultValue: 'a'
})
setOption(option: string) {}

[BenSawary]

Hi Jay, an additional configuration could be dynamic choices. Decorators are used in a static manner, if we want to add the choices dynamically, then we could provide this over a function.

export interface OptionMetadata {
flags: string;
description?: string;
choices?: string[] | () => string[];
defaultValue?: string | boolean;
required?: boolean;
}

An alternative of that approach could be a second Decorator. We could use it in the same way as in the Inquirer API:

@option({
flags: '--option [option]',
defaultValue: 'a'
})
setOption(option: string) {}

@OptionChoicesFor({name: option})
getOptionChoices(): string[] {}

[jmcdo29]

I really like the @OptionFor() approach, so I'll probably go with that over using a function inside the decorator, thanks for calling this out as an option.

[jmcdo29]

Added support in 2.5.0