regexNonStandardFlags

Reports non-standard regular expression flags.

✅ This rule is included in the ts logical presets.

Reports non-standard regular expression flags. Some JavaScript environments support experimental flags not defined in the ECMAScript standard. These flags should be avoided in production code as they may not work in all environments.

The standard flags are: d, g, i, m, s, u, v, y.

Examples

Non-Standard Flag in Literal

❌ Incorrect

const pattern = /foo/l;

✅ Correct

const pattern = /foo/g;

Non-Standard Flag in RegExp Constructor

❌ Incorrect

const pattern = new RegExp("foo", "gxl");

✅ Correct

const pattern = new RegExp("foo", "gi");

Options

This rule is not configurable.

When Not To Use It

If you are targeting a specific JavaScript environment that supports non-standard flags (such as certain embedded environments or experimental runtimes), you might want to disable this rule.

Further Reading

• MDN: RegExp
• ECMAScript Regular Expression Flags

Equivalents in Other Linters

• ESLint: regexp/no-non-standard-flag