Disallow unnecessary character classes.
configuration in plugin:clean-regex/recommended: "warn"
Unnecessary character classes contain only one character and can be trivially
removed. E.g. [a], [\x61], [\?].
Sometimes characters have to be escaped, in order to remove the character class
(e.g. a[+] -> a\+). The automatic escaping can be disabled by using
{ avoidEscape: true } in the rule configuration.
Note: This option does not affect characters already escaped in the character
class (e.g. a[\+] -> a\+).
Note: \b means backspace (\x08) inside of character classes but it will
interpreted as a boundary assertion anywhere else, so it will be escaped as
\x08.
/a[+]/ -> /a\+/
/a[.]/ -> /a\./
/[\b]/ -> /\x08/
/a[\s]/ -> /a\s/
/a[\+]/ -> /a\+//a[+]/ -> /a[+]/
/a[.]/ -> /a[.]/
/[\b]/ -> /[\b]/
/a[\s]/ -> /a\s/
/a[\+]/ -> /a\+/