Option identified as argument

[AlexandraMN]

I was using some examples from this repository to check if I can use commander in my application and I have a question.
Example: options-common.js program
Code:

const commander = require('commander');
const program = new commander.Command();

program
  .option('-d, --debug', 'output extra debugging')
  .option('-s, --small', 'small pizza size')
  .option('-p, --pizza-type <type>', 'flavour of pizza');

program.parse(process.argv);

const options = program.opts();
if (options.debug) console.log(options);
console.log('pizza details:');
if (options.small) console.log('- small pizza size');
if (options.pizzaType) console.log(`- ${options.pizzaType}`);

The pizza-type option requires an argument, but if I do not add an argument and I use another option like -s, the pizza-type option use it as an argument.

node options-common.js --pizza-type -s        
pizza details:
- -s

My expectation was to receive the argument missing message. I want to add some checks in my code for the received argument, but I thought that the program would identify firstly that -s is another option, before verifying something else.

[shadowspawn]

This is intended behaviour, although surprising when you first encounter it and expect something different! It is the standard POSIX behaviour for options which have a required option-argument.

Quoting from different parts of the README (see the README for the associated code):

Options with an expected option-argument are greedy and will consume the following argument whatever the value. So --id -xyz reads -xyz as the option-argument.

Options with an optional option-argument are not greedy and will ignore arguments starting with a dash. So id behaves as a boolean option for --id -5, but you can use a combined form if needed like --id=-5.