Using an array as an object key

[nhz-io]

Consider this block:

minimist/index.js

Lines 52 to 66 in 62fde7d

	Object.keys(opts.alias || {}).forEach(function (key) {
	aliases[key] = [].concat(opts.alias[key]);
	aliases[key].forEach(function (x) {
	aliases[x] = [key].concat(aliases[key].filter(function (y) {
	return x !== y;
	}));
	});
	});
	[].concat(opts.string).filter(Boolean).forEach(function (key) {
	flags.strings[key] = true;
	if (aliases[key]) {
	flags.strings[aliases[key]] = true;
	}
	});

Here it builds an array of aliased args:

minimist/index.js

Lines 55 to 57 in 62fde7d

	aliases[x] = [key].concat(aliases[key].filter(function (y) {
	return x !== y;
	}));

And here it uses this array as a key for strings:

minimist/index.js

Line 64 in 62fde7d

flags.strings[aliases[key]] = true;

Which will just result in:

{
  strings: {
    "[object Object]": true
  }
}

It should either build flat aliases or iterate over the nested array

[ljharb]

Is there a test case you can suggest that indicates the problem?

[nhz-io]

Actually, the array will be turned into string joined with comma. But regardless, the logic still seems broken to me.
I will update later if i find a use case where this breaks the functionalilty.

[ljharb]

In which browser is an array used as an object key not toStringed such that it auto-joins?

[nhz-io]

In which browser is an array used as an object key not toStringed such that it auto-joins?

My mistake. It something i messed up it seems

[nhz-io]

Found the case where it breaks.

minimist = require('minimist')

console.log(minimist(["-f123"], {
	alias: {
		foo: ["f"]
	},
	string: ["foo"]
}))

/* Outputs:
  { _: [], f: '123', foo: '123' }
  Works as intended because flags.strings key will be: {"foo": true, "f": true}
  */

console.log(minimist(["-f123"], {
	alias: {
		foo: ["f", "g"]
	},
	string: ["foo"]
}))
/* Outputs:
  { _: [], f: 123, foo: 123, g: 123 }
  Broken because flags.strings will be: {"foo": true, "f,g": true}
*/

Its an edge-case, but its still breaks the convention

[ljharb]

The readme indeed says "an object mapping string names to strings or arrays of string argument names to use as aliases", so this seems like a bug.

[shadowspawn]

Took me a while to make sense of it, but I agree it is a bug. An alias with multiple items does not play well with the opts.string configuration.

(I suspect there are some holes in the combination of aliases with opts.boolean too, but aliasIsBoolean() means the edge cases are quite different. Separate issue.)

[nhz-io]

It should either build flat aliases or iterate over the nested array

Well, aliases cannot be flat without breaking this:

minimist/index.js

Lines 125 to 127 in 62fde7d

	(aliases[key] || []).forEach(function (x) {
	setKey(argv, x.split('.'), value);
	});