comma-dangle eslint error in legacy rules

[GeyseR]

Hi!

In https://github.com/airbnb/javascript/tree/master/es5#commas you have note about trailing commas: Additional trailing comma: Nope. This can cause problems with IE6/7 and IE9 if it's in quirksmode. Also, in some implementations of ES3 would add length to an array if it had an additional trailing comma

But comma-dangle rule is presented in airbnb/legacy rule set.

What do you think about excluding this rule from airbnb/legacy?

[ljharb]

(It's in

javascript/packages/eslint-config-airbnb/rules/errors.js

Lines 3 to 4 in 88d5084

	// disallow trailing commas in object literals
	'comma-dangle': [2, 'always-multiline'],

which included here

javascript/packages/eslint-config-airbnb/legacy.js

Line 4 in 88d5084

'eslint-config-airbnb/rules/errors',

)

I think that perhaps the legacy ruleset should disallow trailing commas, and the ES6 rule set should require them - there's some rule rearranging that could be done here.

[ischyron]

how to turn on legacy ruleset via comment ?

[ljharb]

@ischyron I'm not sure why you'd want to do that - you could certainly toggle the rule for comma-dangle by a comment tho. Can you elaborate?