Disallow unnecessary escape usage (no-useless-escape)

Escaping non-special characters in strings, template literals, and regular expressions doesn't have any effect, as demonstrated in the following example:

let foo = "hol\a"; // > foo = "hola"
let bar = `${foo}\!`; // > bar = "hola!"
let baz = /\:/ // same functionality with /:/

Rule Details

This rule flags escapes that can be safely removed without changing behavior.

Examples of incorrect code for this rule:

/*eslint no-useless-escape: "error"*/

"\'";
'\"';
"\#";
"\e";
`\"`;
`\"${foo}\"`;
`\#{foo}`;
/\!/;
/\@/;

Examples of correct code for this rule:

/*eslint no-useless-escape: "error"*/

"\"";
'\'';
"\x12";
"\u00a9";
"\371";
"xs\u2111";
`\``;
`\${${foo}\}`;
`$\{${foo}\}`;
/\\/g;
/\t/g;
/\w\$\*\^\./;

When Not To Use It

If you don't want to be notified about unnecessary escapes, you can safely disable this rule. Source: http://eslint.org/docs/rules/