no-empty-character-class

[] in a regular expression is a character class with no characters in it. It matches nothing, so /^#[]{6}$/ never matches any string. Most often someone forgot to fill in the class, or meant the text [], which is written \[].

[^], which matches any character, is allowed. Only regular expression literals are checked, not strings passed to new RegExp().

This rule is on by default.

Configure

On by default as a warning. To turn it off:

[lint.rules]
"no-empty-character-class" = "off" # or "error"

Examples

Reported:

const isHexColor = /^#[]{6}$/.test(color);

Not reported:

const isHexColor = /^#[0-9a-f]{6}$/i.test(color);

const anyCharacter = /[^]/;
const emptyArrayText = /\[]/;
const notChecked = new RegExp("[]");