Cannot declare that boolean values do not accept an argument.

[coreyfarrell]

I'd like the ability to tell yargs-parser that boolean arguments do not accept values in the next argument. Lets say I have mytest.js:

#!/usr/bin/env node
'use strict';

const argv = require('yargs-parser')(process.argv.slice(2), {
	boolean: ['all'],
	narg: {
		all: 0
	},
	configuration: {
		'halt-at-non-option': true
	}
});
console.log(argv);

Currently:

$ ./mytest.js --all echo hi
{ _: [ 'echo', 'hi' ], all: true }
$ ./mytest.js --all true
{ _: [], all: true }
$ ./mytest.js --all false
{ _: [], all: false }
$ ./mytest.js --no-all true
{ _: [ 'true' ], all: false }
$ ./mytest.js --no-all false
{ _: [ 'false' ], all: false }

I feel that narg: {all: 0} should tell yargs-parser that --all should be processed without looking at the next argument. I think it's only valid to set narg of a boolean to 0 or 1. The following shows the desired output for the currently failing test cases:

$ ./mytest.js --all true
{ _: [ 'true' ], all: true }
$ ./mytest.js --all false
{ _: [ 'false' ], all: true }