regexUnnecessaryDisjunctions

Reports single-character alternatives in string disjunctions.

✅ This rule is included in the ts logical presets.

Reports single-character alternatives inside \q{...} string disjunctions in regular expressions using the v flag. When a string disjunction alternative contains only one character, that character can be placed directly in the surrounding character class instead.

Examples

Single-Character Alternative Only

A string disjunction containing only a single-character alternative is unnecessary.

❌ Incorrect

const pattern = /[\q{a}]/v;

✅ Correct

const pattern = /[a]/v;

Mixed-Length Alternatives

When a string disjunction has both single-character and multi-character alternatives, the single-character ones can be extracted.

❌ Incorrect

const pattern = /[\q{a|bc}]/v;

✅ Correct

const pattern = /[a\q{bc}]/v;

RegExp Constructor

The rule also checks regex patterns in RegExp constructor calls.

❌ Incorrect

const pattern = new RegExp("[\\q{a}]", "v");

✅ Correct

const pattern = new RegExp("[a]", "v");

Multi-Character Alternatives Are Valid

String disjunctions with only multi-character alternatives are valid.

✅ Correct

const pattern = /[\q{ab|cd}]/v;

Options

This rule is not configurable.

When Not To Use It

If you prefer to keep single-character alternatives inside \q{...} for consistency or readability, you might prefer to disable this rule.

Further Reading

• MDN: Unicode character class escape
• TC39 proposal: RegExp set notation + properties of strings

Equivalents in Other Linters

• ESLint: regexp/no-useless-string-literal