Pattern: Empty alternative in pattern
Issue: -
While (re-)writing long regular expressions, it can happen that one forgets to remove the | character of a former alternative. This rule tries to point out these potential mistakes by reporting all empty alternatives.
If the empty alternative is supposed to match the empty string, then use a quantifier instead. For example, a| should be written as a?.
/* eslint regexp/no-empty-alternative: "error" */
/* ✓ GOOD */
var foo = /(?:)/
var foo = /a+|b*/
/* ✗ BAD */
var foo = /a+|b+|/
var foo = /\|\||\|||\|\|\|/
var foo = /a(?:a|bc|def|h||ij|k)/