react-scripts/node_modules/jest-resolve/build/index.js

Configuration and scripts for Create React App.

/**
 * Copyright (c) 2014, 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.
 *
 * 
 */

'use strict';




const nodeModulesPaths = require('resolve/lib/node-modules-paths');
const path = require('path');
const resolve = require('resolve');
const browserResolve = require('browser-resolve');






















const NATIVE_PLATFORM = 'native';

const nodePaths =
process.env.NODE_PATH ? process.env.NODE_PATH.split(path.delimiter) : null;

class Resolver {





  constructor(moduleMap, options) {
    this._options = {
      browser: options.browser,
      defaultPlatform: options.defaultPlatform,
      extensions: options.extensions,
      hasCoreModules:
      options.hasCoreModules === undefined ? true : options.hasCoreModules,
      moduleDirectories: options.moduleDirectories || ['node_modules'],
      moduleNameMapper: options.moduleNameMapper,
      modulePaths: options.modulePaths,
      platforms: options.platforms };

    this._moduleMap = moduleMap;
    this._moduleNameCache = Object.create(null);
    this._modulePathCache = Object.create(null);
  }

  static findNodeModule(path, options) {
    const paths = options.paths;
    try {
      const resv = options.browser ? browserResolve : resolve;
      return resv.sync(
      path,
      {
        basedir: options.basedir,
        extensions: options.extensions,
        moduleDirectory: options.moduleDirectory,
        paths: paths ? (nodePaths || []).concat(paths) : nodePaths });


    } catch (e) {}
    return null;
  }

  resolveModule(
  from,
  moduleName,
  options)
  {
    const dirname = path.dirname(from);
    const paths = this._options.modulePaths;
    const extensions = this._options.extensions;
    const moduleDirectory = this._options.moduleDirectories;
    const key = dirname + path.delimiter + moduleName;

    // 0. If we have already resolved this module for this directory name,
    //    return a value from the cache.
    if (this._moduleNameCache[key]) {
      return this._moduleNameCache[key];
    }

    // 1. Check if the module is a haste module.
    let module = this.getModule(moduleName);
    if (module) {
      return this._moduleNameCache[key] = module;
    }

    // 2. Check if the module is a node module and resolve it based on
    //    the node module resolution algorithm.
    if (!options || !options.skipNodeResolution) {
      module = Resolver.findNodeModule(moduleName, {
        basedir: dirname,
        browser: this._options.browser,
        extensions,
        moduleDirectory,
        paths });


      if (module) {
        return this._moduleNameCache[key] = module;
      }
    }

    // 3. Resolve "haste packages" which are `package.json` files outside of
    // `node_modules` folders anywhere in the file system.
    const parts = moduleName.split('/');
    module = this.getPackage(parts.shift());
    if (module) {
      try {
        return this._moduleNameCache[key] = require.resolve(
        path.join.apply(path, [path.dirname(module)].concat(parts)));

      } catch (ignoredError) {}
    }

    // 4. Throw an error if the module could not be found. `resolve.sync`
    //    only produces an error based on the dirname but we have the actual
    //    current module name available.
    const relativePath = path.relative(dirname, from);
    const err = new Error(
    `Cannot find module '${ moduleName }' from '${ relativePath || '.' }'`);

    err.code = 'MODULE_NOT_FOUND';
    throw err;
  }

  isCoreModule(moduleName) {
    return this._options.hasCoreModules && resolve.isCore(moduleName);
  }

  getModule(name) {
    return this._moduleMap.getModule(
    name,
    this._options.defaultPlatform,
    this._supportsNativePlatform());

  }

  getPackage(name) {
    return this._moduleMap.getPackage(
    name,
    this._options.defaultPlatform,
    this._supportsNativePlatform());

  }

  getMockModule(from, name) {
    const mock = this._moduleMap.getMockModule(name);
    if (mock) {
      return mock;
    } else {
      const moduleName = this._resolveStubModuleName(from, name);
      if (moduleName) {
        return this.getModule(moduleName) || moduleName;
      }
    }
    return null;
  }

  getModulePaths(from) {
    if (!this._modulePathCache[from]) {
      const moduleDirectory = this._options.moduleDirectories;
      const paths = nodeModulesPaths(from, { moduleDirectory });
      if (paths[paths.length - 1] === undefined) {
        // circumvent node-resolve bug that adds `undefined` as last item.
        paths.pop();
      }
      this._modulePathCache[from] = paths;
    }
    return this._modulePathCache[from];
  }

  _resolveStubModuleName(from, moduleName) {
    const dirname = path.dirname(from);
    const paths = this._options.modulePaths;
    const extensions = this._options.extensions;
    const moduleDirectory = this._options.moduleDirectories;

    const moduleNameMapper = this._options.moduleNameMapper;
    if (moduleNameMapper) {
      for (const mappedModuleName in moduleNameMapper) {
        const regex = moduleNameMapper[mappedModuleName];
        if (regex.test(moduleName)) {
          moduleName = moduleName.replace(regex, mappedModuleName);
          return this.getModule(moduleName) || Resolver.findNodeModule(
          moduleName,
          {
            basedir: dirname,
            browser: this._options.browser,
            extensions,
            moduleDirectory,
            paths });


        }
      }
    }
    return null;
  }

  _supportsNativePlatform() {
    return (this._options.platforms || []).indexOf(NATIVE_PLATFORM) !== -1;
  }}



module.exports = Resolver;