babel.config.js

module.exports = function (api) {
	var validEnv = ["development", "test", "production"];
	var currentEnv = api.env();
	var isDevelopmentEnv = api.env("development");
	var isProductionEnv = api.env("production");
	var isTestEnv = api.env("test");

	if (!validEnv.includes(currentEnv)) {
		throw new Error(
			"Please specify a valid `NODE_ENV` or " +
				'`BABEL_ENV` environment variables. Valid values are "development", ' +
				'"test", and "production". Instead, received: ' +
				JSON.stringify(currentEnv) +
				"."
		);
	}

	return {
		presets: [
			isTestEnv && [
				require("@babel/preset-env").default,
				{
					targets: {
						node: "current",
					},
				},
			],
			(isProductionEnv || isDevelopmentEnv) && [
				require("@babel/preset-env").default,
				{
					forceAllTransforms: true,
					useBuiltIns: "entry",
					corejs: 3,
					modules: false,
					exclude: ["transform-typeof-symbol"],
				},
			],
		].filter(Boolean),
		plugins: [
			require("babel-plugin-macros"),
			require("@babel/plugin-syntax-dynamic-import").default,
			isTestEnv && require("babel-plugin-dynamic-import-node"),
			require("@babel/plugin-transform-destructuring").default,
			[
				require("@babel/plugin-proposal-class-properties").default,
				{
					loose: true,
				},
			],
			[
				require("@babel/plugin-proposal-private-methods").default,
				{
					loose: true,
				},
			],
			[
				require("@babel/plugin-proposal-object-rest-spread").default,
				{
					useBuiltIns: true,
				},
			],
			[
				require("@babel/plugin-proposal-private-property-in-object").default,
				{
					loose: true,
				},
			],
			[
				require("@babel/plugin-transform-runtime").default,
				{
					helpers: false,
					regenerator: true,
					corejs: false,
				},
			],
			[
				require("@babel/plugin-transform-regenerator").default,
				{
					async: false,
				},
			],
		].filter(Boolean),
	};
};