@mrhenry/babel-plugin-core-web

Babel plugin that polyfills browser features.

Bringing @mrhenry/polyfill-library to your babel flow.

why

Maintaining a correct but minimal polyfill bundle from @mrhenry/polyfill-library is a manual process and prone to errors. Babel however knows which features you actually used and the environment you are targeting. Bringing the two together works for us, we hope it does for you too.

install

npm install --save-dev @mrhenry/babel-plugin-core-web

yarn add --dev @mrhenry/babel-plugin-core-web

babel.config.js

module.exports = function(api) {
	/*
		Optionally cache the babel config
		https://babeljs.io/docs/en/config-files#apicache
	*/
	api.cache(true);

	return {
		plugins: [
			// Use browserslist default :
			["@mrhenry/core-web"]
		]
	};
};

module.exports = function(api) {
	/*
		Optionally cache the babel config
		https://babeljs.io/docs/en/config-files#apicache
	*/
	api.cache(true);

	return {
		plugins: [
			// A custom browserslist config :
			["@mrhenry/core-web", {
				browserslist: [
					"last 2 versions",
					">0.5%"
				]
			}]
		]
	};
};

manually describe which browsers

module.exports = function(api) {
	/*
		Optionally cache the babel config
		https://babeljs.io/docs/en/config-files#apicache
	*/
	api.cache(true);

	return {
		plugins: [
			["@mrhenry/core-web", {
				browsers: {
					chrome: "31",
					firefox: "26",
					edge: "12",
					opera: "26",
					safari: "8",
					ie: "11",
				}
			}]
		]
	};
};

webpack config

const babelPresetEnv = require( '@babel/preset-env' );

...

{
	loader: 'babel-loader',
	options: {
		comments: false,
		plugins: [
			[
				'@mrhenry/core-web',
				{
					browserslist: [
						"last 2 versions",
						">0.5%"
					]
				},
			],
		],
		presets: [
			[
				babelPresetEnv,
				{
					corejs: '^3.6.3',
					targets: {
						browsers: ...,
					},
					useBuiltIns: 'usage',
					exclude: [
						"web.dom-collections.iterator",
						"web.dom-collections.for-each",
					],
				},
			],
		],
	},
}

ignore comments

// core-web-ignore @mrhenry/core-web/modules/console.warn
/* core-web-ignore @mrhenry/core-web/modules/console.error */
/*! core-web-ignore @mrhenry/core-web/modules/console.table */

console.warn('A warning!'); /* no polyfill because it is marked as ignored above */
console.error('An error'); /* no polyfill because it is marked as ignored above */
console.table(['A table']); /* no polyfill because it is marked as ignored above */

manually add a polyfill

import "@mrhenry/core-web/modules/Element.prototype.after";

Example with script tags (module vs nomodules)

example migration

issues

If have any trouble using @mrhenry/babel-plugin-core-web please open an issue here. We will try to get back to you as soon as possible.

missing polyfills

If a polyfill is missing from this plugin please open an issue here.

We do take the specification status into consideration before adding new polyfills.