A clean way to get pass through arguments?

[teststaybaka]

Hi, I'm writing a simple CLI tool that triggers the execution of another JS file which also takes command line arguments, but I couldn't figure out a clean way to get pass-through arguments. A short snipet written in TypeScript is shown below.

import { Command } from "commander";
let program = new Command();
program
  .command("run <file>")
  .action(
    (file, options): void => {
      new Builder().build();
      console.log(file);
      console.log(options);
      spawnSync("node", [file, ...options.args], {
        stdio: "inherit",
      });
    });
program.parse();

Then when I execute the CLI as cli run executable.js -- --test-flag, it doesnt' work because options.args contains [ 'executable.js', '--test-flag' ], which seems to match the document though:

leaving any args not consumed by the program options in the program.args array.

Is there a better way to get an array of pass-through arguments, which excludes <file> and other potential positional arguments? Thanks!

[shadowspawn]

1/3: I think what you have might work if you just remove file from the spawn arguments since it is also included in args like:

spawnSync("node", options.args, {
        stdio: "inherit",
      });

[shadowspawn]

2/3: The extra arguments actually get passed to the action handler too. (Currently undocumented, as I am not sure it is useful enough!)

const { Command } = require("commander");
let program = new Command();
program
  .command("run <file>")
  .action(
    (file, options, extraArgs) => {
      console.log(file);
      console.log(extraArgs);
    });
program.parse();

[shadowspawn]

3/3: But my preferred approach is to make it explicit as part of the command so it appears in the help too, like:

const { Command } = require("commander");
let program = new Command();
program
  .command("run <file> [args...]")
  .action(
    (file, args, options) => {
      console.log(file);
      console.log(args);
    });
program.parse();

[teststaybaka]

Thanks for the quick response.

1. I actually want to do some processing to the file name and I guess people could define more positional arguments.
2. I feel this is the best solution.
3. [args...] doesn't work if I need to pass through undefined options. I.e., cli run executable.js --test-flag complains "error: unknown option '--test-flag'". I want to pass through any unknown options, so I couldn't define them ahead of time. I guess we could configure somehow to ignore unknown options but I'm not sure it'd be better than 2).

[shadowspawn]

cli run executable.js --test-flag complains "error: unknown option '--test-flag'"

This is the same behaviour with all three approaches. You still need the -- to stop the option processing. (Or turn on .allowUnknownOptions().)

Like you had in your original post:

cli run executable.js -- --test-flag

[teststaybaka]

I see. I'm actually really surprised that [args...] would capture arguments even after --. Thansks for the help!

[shadowspawn]

Pull Request opened to add .enablePositionalOptions() and .passThroughOptions(): #1427