Disable Unnecessary escape character: \/ no-useless-escape
RegexReactjsEslintRegex Problem Overview
I have this regex of mine that will check the string if it contains link or url (i.e. https://eslint.org/docs/rules/no-useless-escape). Using this regex /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig, I've encountered and error while running my test cases in react about Unnecessary escape character: \/ no-useless-escape. How to disable this eslint-error in order for me to proceed with my test case and use the regex.
Appreciate for any help!
Regex Solutions
Solution 1 - Regex
You can use ESLint and try adding either of the things:-
//eslint-disable-lineon the line to disable warnings.//eslint-disable-next-lineto line before to disable warnings.
See from docs of ESLint, Disabling Rules with Inline Comments.
> To disable all rules on a specific line, use a line or block comment in one of the following formats:
>
> alert('foo'); // eslint-disable-line
>
> // eslint-disable-next-line
> alert('foo');
>
> /* eslint-disable-next-line /
> alert('foo');
>
> alert('foo'); / eslint-disable-line */
You can disable warnings in entire file by adding /* eslint-disable */ at the top of the file.
> To disable rule warnings in an entire file, put a /* eslint-disable */ block comment at the top of the file:
>
> /* eslint-disable */
> alert('foo');
Solution 2 - Regex
It's the \/ in [-A-Z0-9+&@#\/%?=~_|!:,.;] and [-A-Z0-9+&@#\/%=~_|] (NOT the ones in :\/\/). Most characters do not have to be escaped within a character class (square brackets). This should be equivalent: /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#/%?=~_|!:,.;]*[-A-Z0-9+&@#/%=~_|])/ig
See https://www.regular-expressions.info/charclass.html for more info, but the relevant part:
> In most regex flavors, the only special characters or metacharacters > inside a character class are the closing bracket ], the backslash , > the caret ^, and the hyphen -. The usual metacharacters are normal > characters inside a character class, and do not need to be escaped by > a backslash. To search for a star or plus, use [+*]. Your regex will > work fine if you escape the regular metacharacters inside a character > class, but doing so significantly reduces readability.
Solution 3 - Regex
You can also use
/* eslint-disable no-useless-escape */
to disable rule for entire script file.
Solution 4 - Regex
//eslint-disable-next-line
place this above the line of code
OR
/*eslint no-undef: 0*/
place this on the first line of the file(or first line of the script tag) this would make eslint disabled on the whole file
Solution 5 - Regex
\ gives error from below code in my NodeJS typescript project, code editor is VS Code -
Code -
if (!(/^[\-0-9a-zA-Z\.\+_]+@[\-0-9a-zA-Z\.\+_]+\.[a-zA-Z]{2,}$/).test(String(req.body.email))) { ... }
Error -
Unnecessary escape character: \+. (eslintno-useless-escape)
Solution -
//eslint-disable-next-line
Final code -
//eslint-disable-next-line
if (!(/^[\-0-9a-zA-Z\.\+_]+@[\-0-9a-zA-Z\.\+_]+\.[a-zA-Z]{2,}$/).test(String(req.body.email))) { ... }
Solution 6 - Regex
I had a similar warning in react.
> Unnecessary escape character: \# no-useless-escape
Simply just remove whatever is mentioned in the warning. In my case, I had \# in the warning, so I just removed it from the line which was mentioned in the warning.
Solution 7 - Regex
I had the following code snippet for validating an email address:
/[a-zA-Z0-9\.]*@[a-z]*[\.a-z]*/.test(value)
The linter was showing an error due to '\.' inside square brackets ('[]'). Square brackets do not need an escape character ('\') to make use of '.'. I removed the '\' inside '[]' (as shown below) and the error got resolved.
/[a-zA-Z0-9.]*@[a-z]*[.a-z]*/.test(value)