prefer-native-coercion-functions

📝 Prefer using String, Number, BigInt, Boolean, and Symbol directly.

💼 This rule is enabled in the following configs: ✅ recommended, ☑️ unopinionated.

🔧 This rule is automatically fixable by the --fix CLI option.

If a function is equivalent to String, Number, BigInt, Boolean, or Symbol, you should use the built-in one directly. Wrapping the built-in in a function is moot.

Examples

// ❌
const toBoolean = value => Boolean(value);

// ✅
const toBoolean = Boolean;

// ❌
function toNumber(value) {
	return Number(value);
}

if (toNumber(foo) === 1) {}

// ✅
if (Number(foo) === 1) {}

// ❌
const hasTruthyValue = array.some(element => element);

// ✅
const hasTruthyValue = array.some(Boolean);

// ✅
const toStringObject = value => new String(value);

// ✅
const toObject = value => Object(value);

// ✅
const strings = mixedData.filter((value): value is string => value);

Note

We don't check implicit coercion like:

const toString = value => '' + value;

const toNumber = value => +value;

const toBoolean = value => !!value;

It is recommended to enable the built-in ESLint rule no-implicit-coercion for a better experience.