no-undef complains about globalThis

[wmertens]

Tell us about your environment

• ESLint Version: 5.15.1
• Node Version: 10
• npm Version: pnpm 3

What parser (default, Babel-ESLint, etc.) are you using?

babel-eslint

Please show your full configuration:

Configuration

// keep up to date from https://github.com/facebookincubator/create-react-app/blob/master/packages/babel-preset-react-app/index.js

const path = require('path')
const debug = require('debug')
const dbg = debug('stratokit/babel')

const isDev = process.env.NODE_ENV !== 'production'

module.exports = function(context, opts) {
	if (opts == null) {
		opts = {}
	}
	opts.isDev = isDev
	// Workaround to force browser build when webpack config already loaded babel and can't change options
	opts.isBrowser = opts.isBrowser || !!process.env.BROWSER
	const chromeOnly = process.env.CHROME_ONLY === 'true'
	dbg('Babel config', JSON.stringify(opts))
	const {reactHot, noModules, inWebpack} = opts
	const plugins = [
		// Cherrypick lodash methods until https://github.com/webpack/webpack/issues/1750
		!isDev && require.resolve('babel-plugin-lodash'),
		// Provide meta-data for import()s
		require.resolve('react-imported-component/babel'),
		// work with aliases, not necessary when running from webpack
		!inWebpack && [
			require.resolve('babel-plugin-webpack-alias'),
			{config: path.join(__dirname, 'aliases.js')},
		],

		// Adds consistent names to styles
		[
			require.resolve('babel-plugin-styled-components'),
			// Don't minify or preprocess, it breaks our stuff
			{displayName: isDev, pure: true, minify: false},
		],

		// Plugins from create-react-app
		// Adds component stack to warning messages
		isDev && require.resolve('@babel/plugin-transform-react-jsx-source'),
		// Adds __self attribute to JSX which React will use for some warnings
		isDev && require.resolve('@babel/plugin-transform-react-jsx-self'),
		// stage 2, but correct one doesn't work yet - HAS TO COME BEFORE class-properties
		[require.resolve('@babel/plugin-proposal-decorators'), {legacy: true}],
		// class { handleClick = () => { } }
		require.resolve('@babel/plugin-proposal-class-properties'),
		// { ...todo, completed: true }
		require.resolve('@babel/plugin-proposal-object-rest-spread'),
		// Support import() syntax
		require.resolve('@babel/plugin-syntax-dynamic-import'),

		// Support for HMR - keep below transform-regenerator
		// https://github.com/gaearon/react-hot-loader/issues/391
		reactHot && [require.resolve('react-hot-loader/babel')],
	].filter(Boolean)

	const presets = [
		// Latest stable ECMAScript features
		// But turn off modules so webpack can handle them
		// in dev, compile for our dev targets only
		[
			require.resolve('@babel/preset-env'),

			{
				targets: opts.isBrowser
					? {
							browsers: chromeOnly
								? ['last 1 Chrome version']
								: ['> 0.5% in BE', 'IE >= 11', 'Safari >= 9.1'],
					  }
					: // Default to node 8.11.3 in prod; nixpkgs-stable
					  {node: isDev ? true : '8.11.3'},
				// this is either `false` or `undefined`
				modules: !noModules && undefined,
				useBuiltIns: isDev ? undefined : 'entry',
				debug: process.env.NODE_ENV !== 'test',
			},
		],
		// JSX, Flow
		require.resolve('@babel/preset-react'),
		// This crashes on build :(
		// !isDev && require.resolve('babel-preset-minify'),
	].filter(Boolean)

	return {
		presets,
		plugins,
	}
}

What did you do? Please include the actual source code causing the issue, as well as the command that you used to run ESLint.

globalThis.foo

eslint

What did you expect to happen?

globalThis is accepted as a global, since it's stage 3 and enabled in Chrome 71 https://github.com/tc39/proposal-global

What actually happened? Please include the actual, raw output from ESLint.

  8:21  error  'globalThis' is not defined  no-undef

Are you willing to submit a pull request to fix this bug?

Yes but not sure where to start.

[aladdin-add]

globalThis is at stage-3, while ESLint only officially supports the latest final ECMAScript standard.

you can use /*global globalThis*/.

[wmertens]

Is there a way to register a global from the eslint config? I use `globalThis` quite a lot in a pretty large codebase.

[aladdin-add]

you can add globals in your eslint config:

{
  "globals": {
    "globalThis": false, // means it is not writeable
  }
}

refs: https://eslint.org/docs/user-guide/configuring.html#specifying-globals

[wmertens]

Thanks! I couldn't find that :-/