parcel-bundler/lib/transforms/babel/config.js

Blazing fast, zero configuration web application bundler

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");

var _asyncToGenerator2 = _interopRequireDefault(require("@babel/runtime/helpers/asyncToGenerator"));

const getBabelRc = require('./babelrc');

const getEnvConfig = require('./env');

const getJSXConfig = require('./jsx');

const getFlowConfig = require('./flow');

const path = require('path');

const fs = require('@parcel/fs');

const NODE_MODULES = `${path.sep}node_modules${path.sep}`;

const ENV_PLUGINS = require('@babel/preset-env/data/plugins');

const ENV_PRESETS = {
  es2015: true,
  es2016: true,
  es2017: true,
  latest: true,
  env: true,
  '@babel/preset-env': true,
  '@babel/env': true
};

function getBabelConfig(_x) {
  return _getBabelConfig.apply(this, arguments);
}

function _getBabelConfig() {
  _getBabelConfig = (0, _asyncToGenerator2.default)(function* (asset) {
    // Consider the module source code rather than precompiled if the resolver
    // used the `source` field, or it is not in node_modules.
    let pkg = yield asset.getPackage();
    let isSource = !!(pkg && pkg.source && (yield fs.realpath(asset.name)) !== asset.name) || !asset.name.includes(NODE_MODULES); // Try to resolve a .babelrc file. If one is found, consider the module source code.

    let babelrc = yield getBabelRc(asset, isSource);
    isSource = isSource || !!babelrc;
    let envConfig = yield getEnvConfig(asset, isSource);
    let jsxConfig = yield getJSXConfig(asset, isSource);
    let flowConfig = getFlowConfig(asset, isSource);

    if (babelrc && envConfig) {
      // Filter out presets that are already applied by @babel/preset-env
      if (Array.isArray(babelrc.config.presets)) {
        babelrc.config.presets = babelrc.config.presets.filter(preset => {
          return !ENV_PRESETS[getPluginName(preset)];
        });
      } // Filter out plugins that are already applied by @babel/preset-env


      if (Array.isArray(babelrc.config.plugins)) {
        babelrc.config.plugins = babelrc.config.plugins.filter(plugin => {
          return !ENV_PLUGINS[getPluginName(plugin)];
        });
      }
    }

    let result = {};
    mergeConfigs(result, babelrc);
    mergeConfigs(result, envConfig); // Add JSX config if it isn't already specified in the babelrc

    let hasReact = babelrc && (hasPlugin(babelrc.config.presets, ['react', '@babel/react', '@babel/preset-react']) || hasPlugin(babelrc.config.plugins, ['transform-react-jsx', '@babel/transform-react-jsx', '@babel/plugin-transform-react-jsx']));

    if (!hasReact) {
      mergeConfigs(result, jsxConfig);
    } // Add Flow stripping config if it isn't already specified in the babelrc


    let hasFlow = babelrc && hasPlugin(babelrc.config.plugins, ['transform-flow-strip-types', '@babel/transform-flow-strip-types', '@babel/plugin-transform-flow-strip-types']);

    if (!hasFlow) {
      mergeConfigs(result, flowConfig);
    }

    return result;
  });
  return _getBabelConfig.apply(this, arguments);
}

module.exports = getBabelConfig;

function mergeConfigs(result, config) {
  if (!config || (!config.config.presets || config.config.presets.length === 0) && (!config.config.plugins || config.config.plugins.length === 0)) {
    return;
  }

  let merged = result[config.babelVersion];

  if (merged) {
    merged.config.presets = (merged.config.presets || []).concat(config.config.presets || []);
    merged.config.plugins = (merged.config.plugins || []).concat(config.config.plugins || []);
  } else {
    result[config.babelVersion] = config;
  }
}

function hasPlugin(arr, plugins) {
  return Array.isArray(arr) && arr.some(p => plugins.includes(getPluginName(p)));
}

function getPluginName(p) {
  return Array.isArray(p) ? p[0] : p;
}