Package.js

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow
 * @format
 */

'use strict';

const nullthrows = require('nullthrows');
const path = require('path');

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

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

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

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

    let main = getMain(this.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(): string {
    return nullthrows(this.data.name);
  }

  isHaste(): boolean {
    return !!this.data.name;
  }

  redirectRequire(name: string): any | boolean | string {
    // Copied from node-haste/Package.js
    const replacements = getReplacements(this.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: PackageData): string {
  return pkg.main || 'index';
}

// Copied from node-haste/Package.js
function getReplacements(pkg: PackageData) {
  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};
}