no-invalid-regexp.md

title	rule_type	further_reading
no-invalid-regexp	problem	https://es5.github.io/#x7.8.5

An invalid pattern in a regular expression literal is a SyntaxError when the code is parsed, but an invalid string in RegExp constructors throws a SyntaxError only when the code is executed.

Rule Details

This rule disallows invalid regular expression strings in RegExp constructors.

Examples of incorrect code for this rule:

::: incorrect

/*eslint no-invalid-regexp: "error"*/

RegExp('[')

RegExp('.', 'z')

new RegExp('\\')

:::

Examples of correct code for this rule:

::: correct

/*eslint no-invalid-regexp: "error"*/

RegExp('.')

new RegExp

this.RegExp('[')

:::

Please note that this rule validates regular expressions per the latest ECMAScript specification, regardless of your parser settings.

If you want to allow additional constructor flags for any reason, you can specify them using the allowConstructorFlags option. These flags will then be ignored by the rule.

Options

This rule has an object option for exceptions:

• "allowConstructorFlags" is a case-sensitive array of flags

allowConstructorFlags

Examples of correct code for this rule with the { "allowConstructorFlags": ["a", "z"] } option:

::: correct

/*eslint no-invalid-regexp: ["error", { "allowConstructorFlags": ["a", "z"] }]*/

new RegExp('.', 'a')

new RegExp('.', 'az')

:::