Report an error for eslint-disable-line comments that span multiple lines

[not-an-aardvark]

The version of ESLint you are using.

v4.19.1

The problem you want to solve.

It's possible to write a disable-line directive comment that spans multiple lines, like this:

/* eslint-disable-next-line
  foo,
  bar,
  baz
*/

This is potentially confusing because it's not clear which "line" the directive comment is referring to. In fact, the current behavior is that ESLint ignores the directive comment entirely and doesn't disable anything.

Your take on the correct solution to problem.

ESLint should report an error when an eslint-disable-line or eslint-disable-next-line directive comment spans multiple lines, to inform the user that their directive isn't doing anything so that the user can fix the problem.

This was discussed in #9745 (comment) when block comment support for disable-line directives was added. The sentiment at the time was that we couldn't make multi-line disable-line directives an error then since it would be a breaking change, so we decided to warn about them at the time with the plan to make them an error in the next major release.

[not-an-aardvark]

This issue was accepted in today's TSC meeting.