ResolutionRequest.js

/**
 * 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 AsyncTaskGroup = require('../lib/AsyncTaskGroup');
const MapWithDefaults = require('../lib/MapWithDefaults');

const debug = require('debug')('RNP:DependencyGraph');
const util = require('util');
const path = require('path');
const realPath = require('path');
const isAbsolutePath = require('absolute-path');
const getAssetDataFromName = require('../lib/getAssetDataFromName');

import type {HasteFS} from '../types';
import type DependencyGraphHelpers from './DependencyGraphHelpers';
import type HasteMap from './HasteMap';
import type Module from '../Module';
import type ModuleCache from '../ModuleCache';
import type ResolutionResponse from './ResolutionResponse';

type DirExistsFn = (filePath: string) => boolean;

type Options = {
  dirExists: DirExistsFn,
  entryPath: string,
  extraNodeModules: ?Object,
  hasteFS: HasteFS,
  hasteMap: HasteMap,
  helpers: DependencyGraphHelpers,
  // TODO(cpojer): Remove 'any' type. This is used for ModuleGraph/node-haste
  moduleCache: ModuleCache | any,
  platform: string,
  platforms: Set<string>,
  preferNativePlatform: boolean,
};

class ResolutionRequest {
  _dirExists: DirExistsFn;
  _entryPath: string;
  _extraNodeModules: ?Object;
  _hasteFS: HasteFS;
  _hasteMap: HasteMap;
  _helpers: DependencyGraphHelpers;
  _immediateResolutionCache: {[key: string]: string};
  _moduleCache: ModuleCache;
  _platform: string;
  _platforms: Set<string>;
  _preferNativePlatform: boolean;
  static emptyModule: string;

  constructor({
    dirExists,
    entryPath,
    extraNodeModules,
    hasteFS,
    hasteMap,
    helpers,
    moduleCache,
    platform,
    platforms,
    preferNativePlatform,
  }: Options) {
    this._dirExists = dirExists;
    this._entryPath = entryPath;
    this._extraNodeModules = extraNodeModules;
    this._hasteFS = hasteFS;
    this._hasteMap = hasteMap;
    this._helpers = helpers;
    this._moduleCache = moduleCache;
    this._platform = platform;
    this._platforms = platforms;
    this._preferNativePlatform = preferNativePlatform;
    this._resetResolutionCache();
  }

  _tryResolve(action: () => Promise<string>, secondaryAction: () => ?Promise<string>) {
    return action().catch((error) => {
      if (error.type !== 'UnableToResolveError') {
        throw error;
      }
      return secondaryAction();
    });
  }

  // TODO(cpojer): Remove 'any' type. This is used for ModuleGraph/node-haste
  resolveDependency(fromModule: Module | any, toModuleName: string) {
    const resHash = resolutionHash(fromModule.path, toModuleName);

    if (this._immediateResolutionCache[resHash]) {
      return Promise.resolve(this._immediateResolutionCache[resHash]);
    }

    const cacheResult = (result) => {
      this._immediateResolutionCache[resHash] = result;
      return result;
    };

    if (!this._helpers.isNodeModulesDir(fromModule.path)
        && !(isRelativeImport(toModuleName) || isAbsolutePath(toModuleName))) {
      return this._tryResolve(
        () => this._resolveHasteDependency(fromModule, toModuleName),
        () => this._resolveNodeDependency(fromModule, toModuleName)
      ).then(cacheResult);
    }

    return this._resolveNodeDependency(fromModule, toModuleName)
      .then(cacheResult);
  }

  getOrderedDependencies({
    response,
    transformOptions,
    onProgress,
    recursive = true,
  }: {
    response: ResolutionResponse,
    transformOptions: Object,
    onProgress?: ?(finishedModules: number, totalModules: number) => mixed,
    recursive: boolean,
  }) {
    const entry = this._moduleCache.getModule(this._entryPath);

    response.pushDependency(entry);
    let totalModules = 1;
    let finishedModules = 0;

    const resolveDependencies = module =>
      module.getDependencies(transformOptions)
        .then(dependencyNames =>
          Promise.all(
            dependencyNames.map(name => this.resolveDependency(module, name))
          ).then(dependencies => [dependencyNames, dependencies])
        );

    const collectedDependencies = new MapWithDefaults(module => collect(module));
    const crawlDependencies = (mod, [depNames, dependencies]) => {
      const filteredPairs = [];

      dependencies.forEach((modDep, i) => {
        const name = depNames[i];
        if (modDep == null) {
          debug(
            'WARNING: Cannot find required module `%s` from module `%s`',
            name,
            mod.path
          );
          return false;
        }
        return filteredPairs.push([name, modDep]);
      });

      response.setResolvedDependencyPairs(mod, filteredPairs);

      const dependencyModules = filteredPairs.map(([, m]) => m);
      const newDependencies =
        dependencyModules.filter(m => !collectedDependencies.has(m));

      if (onProgress) {
        finishedModules += 1;
        totalModules += newDependencies.length;
        onProgress(finishedModules, totalModules);
      }

      if (recursive) {
        // doesn't block the return of this function invocation, but defers
        // the resulution of collectionsInProgress.done.then(...)
        dependencyModules
          .forEach(dependency => collectedDependencies.get(dependency));
      }
      return dependencyModules;
    };

    const collectionsInProgress = new AsyncTaskGroup();
    function collect(module) {
      collectionsInProgress.start(module);
      const result = resolveDependencies(module)
        .then(deps => crawlDependencies(module, deps));
      const end = () => collectionsInProgress.end(module);
      result.then(end, end);
      return result;
    }

    return Promise.all([
      // kicks off recursive dependency discovery, but doesn't block until it's done
      collectedDependencies.get(entry),

      // resolves when there are no more modules resolving dependencies
      collectionsInProgress.done,
    ]).then(([rootDependencies]) => {
      return Promise.all(
        Array.from(collectedDependencies, resolveKeyWithPromise)
      ).then(moduleToDependenciesPairs =>
        [rootDependencies, new MapWithDefaults(() => [], moduleToDependenciesPairs)]
      );
    }).then(([rootDependencies, moduleDependencies]) => {
      // serialize dependencies, and make sure that every single one is only
      // included once
      const seen = new Set([entry]);
      function traverse(dependencies) {
        dependencies.forEach(dependency => {
          if (seen.has(dependency)) { return; }

          seen.add(dependency);
          response.pushDependency(dependency);
          traverse(moduleDependencies.get(dependency));
        });
      }

      traverse(rootDependencies);
    });
  }

  _resolveHasteDependency(fromModule: Module, toModuleName: string) {
    toModuleName = normalizePath(toModuleName);

    let p = fromModule.getPackage();
    if (p) {
      p = p.redirectRequire(toModuleName);
    } else {
      p = Promise.resolve(toModuleName);
    }

    return p.then((realModuleName) => {
      let dep = this._hasteMap.getModule(realModuleName, this._platform);
      if (dep && dep.type === 'Module') {
        return dep;
      }

      let packageName = realModuleName;
      while (packageName && packageName !== '.') {
        dep = this._hasteMap.getModule(packageName, this._platform);
        if (dep && dep.type === 'Package') {
          break;
        }
        packageName = path.dirname(packageName);
      }

      if (dep && dep.type === 'Package') {
        const potentialModulePath = path.join(
          dep.root,
          path.relative(packageName, realModuleName)
        );
        return this._tryResolve(
          () => this._loadAsFile(
            potentialModulePath,
            fromModule,
            toModuleName,
          ),
          () => this._loadAsDir(potentialModulePath, fromModule, toModuleName),
        );
      }

      throw new UnableToResolveError(
        fromModule,
        toModuleName,
        'Unable to resolve dependency',
      );
    });
  }

  _redirectRequire(fromModule: Module, modulePath: string) {
    return Promise.resolve(fromModule.getPackage()).then(p => {
      if (p) {
        return p.redirectRequire(modulePath);
      }
      return modulePath;
    });
  }

  _resolveFileOrDir(fromModule: Module, toModuleName: string) {
    const potentialModulePath = isAbsolutePath(toModuleName) ?
        toModuleName :
        path.join(path.dirname(fromModule.path), toModuleName);

    return this._redirectRequire(fromModule, potentialModulePath).then(
      realModuleName => {
        if (realModuleName === false) {
          return this._loadAsFile(
            ResolutionRequest.emptyModule,
            fromModule,
            toModuleName,
          );
        }

        return this._tryResolve(
          () => this._loadAsFile(realModuleName, fromModule, toModuleName),
          () => this._loadAsDir(realModuleName, fromModule, toModuleName)
        );
      }
    );
  }

  _resolveNodeDependency(fromModule: Module, toModuleName: string) {
    if (isRelativeImport(toModuleName) || isAbsolutePath(toModuleName)) {
      return this._resolveFileOrDir(fromModule, toModuleName);
    } else {
      return this._redirectRequire(fromModule, toModuleName).then(
        realModuleName => {
          // exclude
          if (realModuleName === false) {
            return this._loadAsFile(
              ResolutionRequest.emptyModule,
              fromModule,
              toModuleName,
            );
          }

          if (isRelativeImport(realModuleName) || isAbsolutePath(realModuleName)) {
            // derive absolute path /.../node_modules/fromModuleDir/realModuleName
            const fromModuleParentIdx = fromModule.path.lastIndexOf('node_modules' + path.sep) + 13;
            const fromModuleDir = fromModule.path.slice(
              0,
              fromModule.path.indexOf(path.sep, fromModuleParentIdx),
            );
            const absPath = path.join(fromModuleDir, realModuleName);
            return this._resolveFileOrDir(fromModule, absPath);
          }

          const searchQueue = [];
          for (let currDir = path.dirname(fromModule.path);
               currDir !== '.' && currDir !== realPath.parse(fromModule.path).root;
               currDir = path.dirname(currDir)) {
            const searchPath = path.join(currDir, 'node_modules');
            if (this._dirExists(searchPath)) {
              searchQueue.push(
                path.join(searchPath, realModuleName)
              );
            }
          }

          if (this._extraNodeModules) {
            const {_extraNodeModules} = this;
            const bits = toModuleName.split(path.sep);
            const packageName = bits[0];
            if (_extraNodeModules[packageName]) {
              bits[0] = _extraNodeModules[packageName];
              searchQueue.push(path.join.apply(path, bits));
            }
          }

          let p = Promise.reject(new UnableToResolveError(fromModule, toModuleName));
          searchQueue.forEach(potentialModulePath => {
            p = this._tryResolve(
              () => this._tryResolve(
                () => p,
                () => this._loadAsFile(potentialModulePath, fromModule, toModuleName),
              ),
              () => this._loadAsDir(potentialModulePath, fromModule, toModuleName)
            );
          });

          return p.catch(error => {
            if (error.type !== 'UnableToResolveError') {
              throw error;
            }
            const hint = searchQueue.length ? ' or in these directories:' : '';
            throw new UnableToResolveError(
              fromModule,
              toModuleName,
              `Module does not exist in the module map${hint}\n` +
                searchQueue.map(searchPath => `  ${path.dirname(searchPath)}\n`).join(', ') + '\n' +
              `This might be related to https://github.com/facebook/react-native/issues/4968\n` +
              `To resolve try the following:\n` +
              `  1. Clear watchman watches: \`watchman watch-del-all\`.\n` +
              `  2. Delete the \`node_modules\` folder: \`rm -rf node_modules && npm install\`.\n` +
              '  3. Reset packager cache: `rm -fr $TMPDIR/react-*` or `npm start --reset-cache`.'
            );
          });
        });
    }
  }

  _loadAsFile(potentialModulePath: string, fromModule: Module, toModule: string) {
    return Promise.resolve().then(() => {
      if (this._helpers.isAssetFile(potentialModulePath)) {
        let dirname = path.dirname(potentialModulePath);
        if (!this._dirExists(dirname)) {
          throw new UnableToResolveError(
            fromModule,
            toModule,
            `Directory ${dirname} doesn't exist`,
          );
        }

        const {name, type} = getAssetDataFromName(potentialModulePath, this._platforms);

        let pattern = name + '(@[\\d\\.]+x)?';
        if (this._platform != null) {
          pattern += '(\\.' + this._platform + ')?';
        }
        pattern += '\\.' + type;

        // Escape backslashes in the path to be able to use it in the regex
        if (path.sep === '\\') {
          dirname = dirname.replace(/\\/g, '\\\\');
        }

        // We arbitrarly grab the first one, because scale selection
        // will happen somewhere
        const [assetFile] = this._hasteFS.matchFiles(
          new RegExp(dirname + '(\/|\\\\)' + pattern)
        );
        if (assetFile) {
          return this._moduleCache.getAssetModule(assetFile);
        }
      }

      let file;
      if (this._hasteFS.exists(potentialModulePath)) {
        file = potentialModulePath;
      } else if (this._platform != null &&
                 this._hasteFS.exists(potentialModulePath + '.' + this._platform + '.js')) {
        file = potentialModulePath + '.' + this._platform + '.js';
      } else if (this._preferNativePlatform &&
                 this._hasteFS.exists(potentialModulePath + '.native.js')) {
        file = potentialModulePath + '.native.js';
      } else if (this._hasteFS.exists(potentialModulePath + '.js')) {
        file = potentialModulePath + '.js';
      } else if (this._hasteFS.exists(potentialModulePath + '.json')) {
        file = potentialModulePath + '.json';
      } else {
        throw new UnableToResolveError(
          fromModule,
          toModule,
          `File ${potentialModulePath} doesn't exist`,
        );
      }

      return this._moduleCache.getModule(file);
    });
  }

  _loadAsDir(potentialDirPath: string, fromModule: Module, toModule: string) {
    return Promise.resolve().then(() => {
      if (!this._dirExists(potentialDirPath)) {
        throw new UnableToResolveError(
          fromModule,
          toModule,
          `Directory ${potentialDirPath} doesn't exist`,
        );
      }

      const packageJsonPath = path.join(potentialDirPath, 'package.json');
      if (this._hasteFS.exists(packageJsonPath)) {
        return this._moduleCache.getPackage(packageJsonPath)
          .getMain().then(
            (main) => this._tryResolve(
              () => this._loadAsFile(main, fromModule, toModule),
              () => this._loadAsDir(main, fromModule, toModule)
            )
          );
      }

      return this._loadAsFile(
        path.join(potentialDirPath, 'index'),
        fromModule,
        toModule,
      );
    });
  }

  _resetResolutionCache() {
    this._immediateResolutionCache = Object.create(null);
  }

}


function resolutionHash(modulePath, depName) {
  return `${path.resolve(modulePath)}:${depName}`;
}

class UnableToResolveError extends Error {
  type: string;
  from: string;
  to: string;

  constructor(fromModule, toModule, message) {
    super();
    this.from = fromModule.path;
    this.to = toModule;
    this.message = util.format(
      'Unable to resolve module `%s` from `%s`: %s',
      toModule,
      fromModule.path,
      message,
    );
    this.type = this.name = 'UnableToResolveError';
  }

}

function normalizePath(modulePath) {
  if (path.sep === '/') {
    modulePath = path.normalize(modulePath);
  } else if (path.posix) {
    modulePath = path.posix.normalize(modulePath);
  }

  return modulePath.replace(/\/$/, '');
}

function resolveKeyWithPromise([key, promise]) {
  return promise.then(value => [key, value]);
}

function isRelativeImport(filePath) {
  return /^[.][.]?(?:[/]|$)/.test(filePath);
}

ResolutionRequest.emptyModule = require.resolve('./assets/empty-module.js');

module.exports = ResolutionRequest;