no-unnecessary-polyfills.md

Enforce the use of built-in methods instead of unnecessary polyfills

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

This rule helps to use existing methods instead of using extra polyfills.

Examples

package.json

// package.json
{
	"engines": {
		"node": ">=8"
	}
}

// ❌
import assign from 'object-assign';

// package.json
{
	"engines": {
		"node": "4"
	}
}

// ✅
import assign from 'object-assign'; // Passes as Object.assign is not supported

Options

Type: object

targets

Type: string | string[] | object

Specify the target versions, which could be a Browserslist query or a targets object. See the core-js-compat targets option for more info.

If the option is not specified, the target versions are defined using the browserslist field in package.json, or as a last resort, the engines field in package.json.

"unicorn/no-unnecessary-polyfills": [
	"error",
	{
		"targets": "node >=12"
	}
]

"unicorn/no-unnecessary-polyfills": [
	"error",
	{
		"targets": [
			"node 14.1.0",
			"chrome 95"
		]
	}
]

"unicorn/no-unnecessary-polyfills": [
	"error",
	{
		"targets": {
			"node": "current",
			"firefox": "15"
		}
	}
]