Double Dash Feature about commander.js

[shadowspawn]

Commander has built-in support for -- to indicate the end of the options, and any remaining arguments will be used without being interpreted.

Alternatively, you may be able to use .passThroughOptions() so you don't even need to use the --. In your example, this is similar to how npx is working.

https://github.com/tj/commander.js#parsing-configuration

[shadowspawn]

If you use .passThroughOptions() then the user does not need to use the --. The arguments after the first one are automatically passed through as normal command-arguments. Try:

./index.js file-name --value 10

[shadowspawn]

The options before the first argument are parsed as normal, so you would call like:

// with passThroughOptions
./index.js --silent filename --value 10

But using -- is fine too! And may be clearer if the syntax of your command does not make it feel natural which option belongs to the program and which gets passed through.

[lxchurbakov]

Oh yeah, I see! That is fantastic. Do you think it would be nice to separate "the rest" of options from the original list? Looks like currently I get all the args altogether (including --) - so I have to manually look for -- and trim array.

program
    .name('run-script')
    .version(version)
    .description('run arbitrary unsafe JS scripts for fun')
    .argument('<filename>', 'script to run')
    .passThroughOptions()
    
// If I do `./index.js file-name -- --value 10`
// I get the following:

program.args: [ 'file-name', '--', '--value', '10' ] 
program.opts: {}

// my goal is to run file-name and pass options (--value 19) there
// like so: require('child_process').exec(`node file-name --value 10`, ...)
// or so: require(...).spawn('node', ['file-name', '--value', '10'], ...)

[lxchurbakov]

I see, awesome! Only thing is how would I differentiate between my args (if --value is for me) and pass-through options if they come after the command? If I have a flag --silent to run that script without attaching it to stdout/stderr, I won't be able to run this like ./index.js filename --silent? I would expect something like ./index.js filename --silent -- --value 10 to make sense.

I mean I understand .passThroughOptions() and I can achieve the behavior I want, but it kinda looks easier to just do -- and pass everything else unvalidated to some kind of program.rest. Anyway, this is a suggestion and the issue is answered, so I will close it shortly. Thank you for your patience and responsiveness