babel.js

// this file is loaded by webpack.base.config.js

/* eslint-disable sort-keys */

function resolver (input) {
  return Array.isArray(input)
    ? input
      .filter((plugin) => !!plugin)
      .map((plugin) =>
        Array.isArray(plugin)
          ? [require.resolve(plugin[0]), plugin[1]]
          : require.resolve(plugin)
      )
    : require.resolve(input);
}

module.exports = {
  presets: resolver([
    ['@babel/preset-env', {
      modules: false, // changed to false to allow code splitting via dynamic import()
      targets: {
        browsers: '>0.25% and last 2 versions and not ie 11 and not OperaMini all',
        node: '10'
      }
    }],
    '@babel/preset-typescript',
    '@babel/preset-react'
  ]),
  plugins: resolver([
    // ordering important, decorators before class properties
    ['@babel/plugin-proposal-decorators', { legacy: true }],
    ['@babel/plugin-proposal-class-properties', { loose: true }],
    ['@babel/plugin-proposal-pipeline-operator', { proposal: 'fsharp' }],
    ['@babel/plugin-proposal-private-methods', { loose: true }],
    '@babel/plugin-proposal-nullish-coalescing-operator',
    '@babel/plugin-proposal-numeric-separator',
    '@babel/plugin-proposal-object-rest-spread',
    '@babel/plugin-proposal-optional-chaining',
    '@babel/plugin-transform-runtime',
    '@babel/plugin-syntax-bigint',
    '@babel/plugin-syntax-dynamic-import',
    '@babel/plugin-syntax-import-meta',
    '@babel/plugin-syntax-top-level-await',
    'babel-plugin-styled-components',
    process.env.NODE_ENV === 'test' && '@polkadot/dev/config/babel-plugin-fix-istanbul'
  ])
};