• Version:
  v10.14.1
• Platform:
  Mac OS Darwin Kernel Version 18.6.0
• Subsystem:

const util = require('util');

const rx = /a/;
rx.lastIndex = 3;

util.isDeepStrictEqual(rx, /a/); // true

util.inspect(rx, {showHidden: true}); // '{ /a/ [lastIndex]: 3 }'
util.inspect(/a/, {showHidden: true}); // '{ /a/ [lastIndex]: 0 }'

My expectation would have been false. I see that areSimilarRegExps does not perform a check on lastIndex, and keyCheck performs a comparison of enumerable keys, and lastIndex is not enumerable. This may be considered correct, but it feels wrong to me.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/lastIndex

Thankyou for your time and consideration.