sequences

Reports using the comma operator in expressions.

✅ This rule is included in the ts untyped preset.

The comma operator evaluates each of its operands and returns the value of the last operand. It can hide side effects and make code harder to read. Prefer writing separate expressions or statements instead.

Examples

❌ Incorrect

const result = (doSideEffect(), computeValue());

✅ Correct

doSideEffect();
const result = computeValue();

Options

This rule is not configurable.

When Not To Use It

Some developers prefer the succinct style of sequences and find it more readable. If you explicitly prefer sequences then you can disable this rule.

Further Reading

• MDN: Comma operator

Equivalents in Other Linters

• Biome: noCommaOperator
• ESLint: no-sequences