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unicorn/prefer-number-properties Restriction

⚠️ 🛠️ A dangerous auto-fix is available for this rule.

What it does

Disallows use of parseInt(), parseFloat(), isNaN(), isFinite(), NaN, Infinity and -Infinity as global variables.

Why is this bad?

ECMAScript 2015 moved globals onto the Number constructor for consistency and to slightly improve them. This rule enforces their usage to limit the usage of globals:

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

Examples

Examples of incorrect code for this rule:

const foo = parseInt("10", 2);
const bar = parseFloat("10.5");

Examples of correct code for this rule:

const foo = Number.parseInt("10", 2);
const bar = Number.parseFloat("10.5");

Configuration

This rule accepts a configuration object with the following properties:

checkInfinity

type: boolean

default: false

If set to true, checks for usage of Infinity and -Infinity as global variables.

checkNaN

type: boolean

default: true

If set to true, checks for usage of NaN as a global variable.

How to use

To enable this rule using the config file or in the CLI, you can use:

Config (.oxlintrc.json)

{
  "rules": {
    "unicorn/prefer-number-properties": "error"
  }
}

Config (oxlint.config.ts)

import { defineConfig } from "oxlint";

export default defineConfig({
  rules: {
    "unicorn/prefer-number-properties": "error",
  },
});

CLI

oxlint --deny unicorn/prefer-number-properties

Version

This rule was added in v0.0.19.

References

• Rule Source
• Upstream rule docs
• Open rule in Oxc Playground