prefer-number-properties.md

Prefer Number static properties over global ones.

Enforces the use of:

• Number.parseInt() over parseInt() (fixable)
• Number.parseFloat() over parseFloat() (fixable)
• Number.isNaN() over isNaN() (they have slightly different behavior)
• Number.isFinite() over isFinite() (they have slightly different behavior)
• Number.NaN over NaN (fixable)
• Number.POSITIVE_INFINITY over Infinity (fixable)
• Number.NEGATIVE_INFINITY over -Infinity (fixable)

This rule is partly fixable.

Fail

const foo = parseInt('10', 2);

const foo = parseFloat('10.5');

const foo = isNaN(10);

const foo = isFinite(10);

if (Object.is(foo, NaN)) {}

const isPositiveZero = value => value === 0 && 1 / value === Infinity;

const isNegativeZero = value => value === 0 && 1 / value === -Infinity;

const {parseInt} = Number;
const foo = parseInt('10', 2);

Pass

const foo = Number.parseInt('10', 2);

const foo = Number.parseFloat('10.5');

const foo = Number.isNaN(10);

const foo = Number.isFinite(10);

if (Object.is(foo, Number.NaN)) {}

const isPositiveZero = value => value === 0 && 1 / value === Number.POSITIVE_INFINITY;

const isNegativeZero = value => value === 0 && 1 / value === Number.NEGATIVE_INFINITY;

Options

Type: object

checkInfinity

Type: boolean
Default: true

Pass checkInfinity: false to disable check on Infinity.

Fail

// eslint unicorn/prefer-number-properties: ["error", {"checkInfinity": true}]
const foo = Infinity;

// eslint unicorn/prefer-number-properties: ["error", {"checkInfinity": true}]
const foo = -Infinity;

Pass

// eslint unicorn/prefer-number-properties: ["error", {"checkInfinity": false}]
const foo = Infinity;

// eslint unicorn/prefer-number-properties: ["error", {"checkInfinity": false}]
const foo = -Infinity;