Rule Proposal: no-ascii

Hi everyone. One day my teammate wrote object key with non-ASCII characters. It led to problems with renaming. So I want proposal new rule no-ascii.

When does this rule warn? Please describe and show example code:

// Russian letter `Й`.
var obj = {
  Й: 'value'
};

// Japanese variable.
var 日 = 'Japanese';
日.length; // 8

Is this rule preventing an error or is it stylistic?

In JS there isn’t prohibited non-ASCII characters (it works correctly), but in some projects this is disallowed.

Why is this rule a candidate for inclusion instead of creating a custom rule?

I think it’s global rule for everyone.

Are you willing to create the rule yourself?

I found solution by @fand, but I made some changes.

[ilyavolodin]

I think this can already be accomplished with id-match rule with the following configuration:

"id-match": ["error", "^[a-zA-Z]*$"]

[sigorilla]

Oh, thank you @ilyavolodin. That’s what I need!