Regular expression not working with \ and ] - regex

Question

I have a regex for validating a password which has to be at least 8 chars and must contain letter(upper and lower case) number and a special character from set ^ $ * . [ ] { } ( ) ? - " ! # # % & / \ , > < ' : ; | _ ~ ` .
I face 2 problems, after adding the / to the reg exp its not recognized (other characters are still working OK. If I add the /] as well the expression no longer works (everything is invalid though the pattern seems to be ok in the browser debug mode).
The regex string
static get PASSWORD_VALIDATION_REGEX(): string {
return '(?=.*[a-z])(?=.*[0-9])(?=.*[A-Z])' + // contains lowercase number uppercase
'(?=.*[\-~\$#!%#<>\|\`\\\/\[;:=\+\{\}\.\(\)*^\?&\"\,\'])' + // special
'.{8,}'; // more than allowed char
}
I used the regexp as a form validator and as a match in function
password: ['', {validators: [Validators.required,
Validators.pattern(StringUtils.PASSWORD_VALIDATION_REGEX)
],
updateOn: 'change'
}
]
//....
value.match(StringUtils.PASSWORD_VALIDATION_REGEX)
Tried to use only (?=.*[\\]) for the special chars list, in that case I've received a console error
Invalid regular expression: /^(?=.*[a-z])(?=.*[0-9])(?=.*[A-Z])(?=.*[\]).{8,}$/: Unterminated character class
For '(?=.*[\]])' no console error but the following error is present in the form validation 'pattern'
actualValue: "AsasassasaX000[[][]"
requiredPattern: "^(?=.*[a-z])(?=.*[0-9])(?=.*[A-Z])(?=.*[]]).{8,}$"
The same value and pattern fails on https://regex101.com/
Thanks for your help / suggestions in advance!

Answer 1

You have overescaped your pattern and failed to escape the ] char correctly. In JavaScript regex, ] inside a character class must be escaped.
If you are confused with how to define escapes inside a string literal (and it is rather confusing indeed), you should use a regex literal. One thing to remember about the regex use with Validators.pattern is that the string pattern is anchored by the Angular framework by enclosing the whole pattern with ^ and $, so these anchors must be present when you define the pattern as a regex literal.
Use
static get PASSWORD_VALIDATION_REGEX(): string {
return /^(?=.*[a-z])(?=.*[0-9])(?=.*[A-Z])(?=.*[-~$#!%#<>|`\\\/[\];:=+{}.()*^?&",']).{8,}$/;
}
Note the \] that matches a ] char and \\ to match \ inside [...].