react-native/packager/src/ModuleGraph/node-haste/Package.js

A framework for building native apps using React

/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @flow
 */

'use strict';

const nullthrows = require('fbjs/lib/nullthrows');
const path = require('path');

import type {PackageData} from '../types.flow';

module.exports = class Package {
  data: Promise<PackageData>;
  path: string;
  root: string;
  type: 'Package';

  constructor(packagePath: string, data: Promise<PackageData>) {
    this.data = data;
    this.path = packagePath;
    this.root = path.dirname(packagePath);
    this.type = 'Package';
  }

  getMain() {
    // Copied from node-haste/Package.js
    return this.data.then(data => {
      const replacements = getReplacements(data);
      if (typeof replacements === 'string') {
        return path.join(this.root, replacements);
      }

      let main = getMain(data);

      if (replacements && typeof replacements === 'object') {
        main = replacements[main] ||
          replacements[main + '.js'] ||
          replacements[main + '.json'] ||
          replacements[main.replace(/(\.js|\.json)$/, '')] ||
          main;
      }

      return path.join(this.root, main);
    });
  }

  getName() {
    return this.data.then(p => nullthrows(p.name));
  }

  isHaste() {
    return this.data.then(p => !!p.name);
  }

  redirectRequire(name: string) {
    // Copied from node-haste/Package.js
    return this.data.then(data => {
      const replacements = getReplacements(data);

      if (!replacements || typeof replacements !== 'object') {
        return name;
      }

      if (!path.isAbsolute(name)) {
        const replacement = replacements[name];
        // support exclude with "someDependency": false
        return replacement === false
          ? false
          : replacement || name;
      }

      let relPath = './' + path.relative(this.root, name);
      if (path.sep !== '/') {
        relPath = relPath.replace(new RegExp('\\' + path.sep, 'g'), '/');
      }

      let redirect = replacements[relPath];

      // false is a valid value
      if (redirect == null) {
        redirect = replacements[relPath + '.js'];
        if (redirect == null) {
          redirect = replacements[relPath + '.json'];
        }
      }

      // support exclude with "./someFile": false
      if (redirect === false) {
        return false;
      }

      if (redirect) {
        return path.join(
          this.root,
          redirect
        );
      }

      return name;
    });
  }
};

function getMain(pkg) {
  return pkg.main || 'index';
}

// Copied from node-haste/Package.js
function getReplacements(pkg) {
  let rn = pkg['react-native'];
  let browser = pkg.browser;
  if (rn == null) {
    return browser;
  }

  if (browser == null) {
    return rn;
  }

  const main = getMain(pkg);
  if (typeof rn !== 'object') {
    rn = {[main]: rn};
  }

  if (typeof browser !== 'object') {
    browser = {[main]: browser};
  }

  // merge with "browser" as default,
  // "react-native" as override
  return {...browser, ...rn};
}