Replacing node-haste with jest-haste-map

Summary: Modified `node-haste` implementation to use the much faster `jest-haste-map` under the hood. The underlying `fastfs` now gets passed the entire file list from the `jest-haste-map` rather than crawl the filesystem.

Reviewed By: cpojer

Differential Revision: D3724387

fbshipit-source-id: 447d58ea0edf283662ec23d1e2deee992cf8d240

package.json

@@ -166,6 +166,7 @@
     "image-size": "^0.3.5",
     "immutable": "~3.7.6",
     "inquirer": "^0.12.0",
+    "jest-haste-map": "15.0.1",
     "joi": "^6.6.1",
     "json-stable-stringify": "^1.0.1",
     "json5": "^0.4.0",

packager/react-packager/src/Bundler/index.js

@@ -143,19 +143,20 @@ class Bundler {
     });
 
     this._resolver = new Resolver({
-      projectRoots: opts.projectRoots,
-      blacklistRE: opts.blacklistRE,
-      polyfillModuleNames: opts.polyfillModuleNames,
-      moduleFormat: opts.moduleFormat,
-      assetRoots: opts.assetRoots,
-      fileWatcher: opts.fileWatcher,
       assetExts: opts.assetExts,
+      assetRoots: opts.assetRoots,
+      blacklistRE: opts.blacklistRE,
       cache: this._cache,
+      extraNodeModules: opts.extraNodeModules,
+      fileWatcher: opts.fileWatcher,
+      minifyCode: this._transformer.minify,
+      moduleFormat: opts.moduleFormat,
+      polyfillModuleNames: opts.polyfillModuleNames,
+      projectRoots: opts.projectRoots,
+      resetCache: opts.resetCache,
       transformCode:
         (module, code, options) =>
           this._transformer.transformFile(module.path, code, options),
-      extraNodeModules: opts.extraNodeModules,
-      minifyCode: this._transformer.minify,
     });
 
     this._projectRoots = opts.projectRoots;

packager/react-packager/src/Resolver/index.js

@@ -57,6 +57,10 @@ const validateOpts = declareOpts({
   minifyCode: {
     type: 'function',
   },
+  resetCache: {
+    type: 'boolean',
+    default: false,
+  },
 });
 
 const getDependenciesValidateOpts = declareOpts({
@@ -109,6 +113,8 @@ class Resolver {
       transformCode: opts.transformCode,
       extraNodeModules: opts.extraNodeModules,
       assetDependencies: ['react-native/Libraries/Image/AssetRegistry'],
+      // for jest-haste-map
+      resetCache: options.resetCache,
     });
 
     this._minifyCode = opts.minifyCode;

packager/react-packager/src/Server/__tests__/Server-test.js

@@ -87,6 +87,7 @@ describe('processRequest', () => {
       jest.fn().mockReturnValue({
         getDependecyGraph: jest.fn().mockReturnValue({
           getHasteMap: jest.fn().mockReturnValue({on: jest.fn()}),
+          load: jest.fn(() => Promise.resolve()),
         }),
       });
 

packager/react-packager/src/Server/index.js

@@ -241,14 +241,14 @@ class Server {
     this._fileWatcher.on('all', this._onFileChange.bind(this));
 
     // changes to the haste map can affect resolution of files in the bundle
-    this._bundler
+    const dependencyGraph = this._bundler.getResolver().getDependecyGraph();
-      .getResolver()
+
-      .getDependecyGraph()
+    dependencyGraph.load().then(() => {
-      .getHasteMap()
+      dependencyGraph.getHasteMap().on('change', () => {
-      .on('change', () => {
         debug('Clearing bundle cache due to haste map change');
         this._clearBundles();
       });
+    });
 
     this._debouncedFileChangeHandler = debounceAndBatch(filePaths => {
       // only clear bundles for non-JS changes
@@ -292,7 +292,7 @@ class Server {
   }
 
   buildBundle(options) {
-    return Promise.resolve().then(() => {
+    return this._bundler.getResolver().getDependecyGraph().load().then(() => {
       if (!options.platform) {
         options.platform = getPlatformExtension(options.entryFile);
       }
@@ -692,7 +692,11 @@ class Server {
         }
       },
       error => this._handleError(res, JSON.stringify(options), error)
-    ).done();
+    ).catch(error => {
+      process.nextTick(() => {
+        throw error;
+      });
+    });
   }
 
   _symbolicate(req, res) {

packager/react-packager/src/node-haste/DependencyGraph/DeprecatedAssetMap.js

@@ -9,73 +9,22 @@
 'use strict';
 
 const AssetModule_DEPRECATED = require('../AssetModule_DEPRECATED');
-const Fastfs = require('../fastfs');
 const debug = require('debug')('ReactNativePackager:DependencyGraph');
 const path = require('../fastpath');
 
 class DeprecatedAssetMap {
   constructor({
-    fsCrawl,
-    roots,
     assetExts,
-    fileWatcher,
-    ignoreFilePath,
     helpers,
-    activity,
-    enabled,
     platforms,
+    files,
   }) {
-    if (roots == null || roots.length === 0 || !enabled) {
-      this._disabled = true;
-      return;
-    }
-
     this._helpers = helpers;
     this._map = Object.create(null);
     this._assetExts = assetExts;
-    this._activity = activity;
     this._platforms = platforms;
 
-    if (!this._disabled) {
+    files.forEach(file => this._processAsset(file));
-      this._fastfs = new Fastfs(
-        'Assets',
-        roots,
-        fileWatcher,
-        { ignore: ignoreFilePath, crawling: fsCrawl, activity }
-      );
-
-      this._fastfs.on('change', this._processFileChange.bind(this));
-    }
-  }
-
-  build() {
-    if (this._disabled) {
-      return Promise.resolve();
-    }
-
-    return this._fastfs.build().then(
-      () => {
-        const activity = this._activity;
-        let processAsset_DEPRECATEDActivity;
-        if (activity) {
-          processAsset_DEPRECATEDActivity = activity.startEvent(
-            'Building (deprecated) Asset Map',
-            null,
-            {
-              telemetric: true,
-            },
-          );
-        }
-
-        this._fastfs.findFilesByExts(this._assetExts).forEach(
-          file => this._processAsset(file)
-        );
-
-        if (activity) {
-          activity.endEvent(processAsset_DEPRECATEDActivity);
-        }
-      }
-    );
   }
 
   resolve(fromModule, toModuleName) {
@@ -105,7 +54,7 @@ class DeprecatedAssetMap {
     }
   }
 
-  _processFileChange(type, filePath, root, fstat) {
+  processFileChange(type, filePath, root, fstat) {
     const name = assetName(filePath);
     if (type === 'change' || type === 'delete') {
       delete this._map[name];

packager/react-packager/src/node-haste/__mocks__/graceful-fs.js

@@ -77,6 +77,15 @@ fs.readFile.mockImpl(function(filepath, encoding, callback) {
   }
 });
 
+fs.readFileSync.mockImpl(function(filepath, encoding) {
+  const node = getToNode(filepath);
+  // dir check
+  if (node && typeof node === 'object' && node.SYMLINK == null) {
+    throw new Error('Error readFileSync a dir: ' + filepath);
+  }
+  return node;
+});
+
 fs.stat.mockImpl((filepath, callback) => {
   callback = asyncCallback(callback);
   let node;
@@ -121,6 +130,31 @@ fs.statSync.mockImpl((filepath) => {
   };
 });
 
+fs.lstat.mockImpl((filepath, callback) => {
+  callback = asyncCallback(callback);
+  let node;
+  try {
+    node = getToNode(filepath);
+  } catch (e) {
+    callback(e);
+    return;
+  }
+
+  if (node && typeof node === 'object') {
+    callback(null, {
+      isDirectory: () => true,
+      isSymbolicLink: () => false,
+      mtime,
+    });
+  } else {
+    callback(null, {
+      isDirectory: () => false,
+      isSymbolicLink: () => false,
+      mtime,
+    });
+  }
+});
+
 fs.lstatSync.mockImpl((filepath) => {
   const node = getToNode(filepath);
 

packager/react-packager/src/node-haste/__tests__/DependencyGraph-test.js

@@ -12,6 +12,99 @@ jest.autoMockOff();
 jest.useRealTimers();
 jest.mock('fs');
 
+// This is an ugly hack:
+// * jest-haste-map uses `find` for fast file system crawling which won't work
+//   when we mock the file system in node. This mock copies the node crawler's
+//   implementation and always falls back to the node crawling mechanism.
+//   Ideally we'll make this an option in jest-haste-map to force it to use
+//   the node crawler.
+jest.mock('jest-haste-map/build/crawlers/node', () => {
+  const H = require('jest-haste-map/build/constants');
+
+  const fs = require('fs');
+  const path = require('path');
+
+  function find(
+  roots,
+  extensions,
+  ignore,
+  callback)
+  {
+    const result = [];
+    let activeCalls = 0;
+
+    function search(directory) {
+      activeCalls++;
+      fs.readdir(directory, (err, names) => {
+        activeCalls--;
+
+        names.forEach(file => {
+          file = process.platform === 'win32' ?
+            path.win32.join(directory, file) :
+            path.join(directory, file);
+          if (ignore(file)) {
+            return;
+          }
+          activeCalls++;
+
+          fs.lstat(file, (err, stat) => {
+            activeCalls--;
+
+            if (!err && stat && !stat.isSymbolicLink()) {
+              if (stat.isDirectory()) {
+                search(file);
+              } else {
+                const ext = path.extname(file).substr(1);
+                if (extensions.indexOf(ext) !== -1) {
+                  result.push([file, stat.mtime.getTime()]);
+                }
+              }
+            }
+            if (activeCalls === 0) {
+              callback(result);
+            }
+          });
+        });
+
+        if (activeCalls === 0) {
+          callback(result);
+        }
+      });
+    }
+
+    roots.forEach(search);
+  }
+
+  return function nodeCrawl(
+  roots,
+  extensions,
+  ignore,
+  data)
+  {
+    return new Promise(resolve => {
+      const callback = list => {
+        const files = Object.create(null);
+        list.forEach(fileData => {
+          const name = fileData[0];
+          const mtime = fileData[1];
+          const existingFile = data.files[name];
+          if (existingFile && existingFile[H.MTIME] === mtime) {
+            files[name] = existingFile;
+          } else {
+            // See ../constants.js
+            files[name] = ['', mtime, 0, []];
+          }
+        });
+        data.files = files;
+        resolve(data);
+      };
+
+      find(roots, extensions, ignore, callback);
+    });
+  };
+
+});
+
 const mocksPattern = /(?:[\\/]|^)__mocks__[\\/]([^\/]+)\.js$/;
 
 jasmine.DEFAULT_TIMEOUT_INTERVAL = 10000;
@@ -103,11 +196,15 @@ describe('DependencyGraph', function() {
       ],
       platforms: ['ios', 'android'],
       shouldThrowOnUnresolvedErrors: () => false,
+      useWatchman: false,
+      maxWorkers: 1,
+      resetCache: true,
     };
   });
 
   describe('get sync dependencies (posix)', function() {
     let DependencyGraph;
+    const consoleWarn = console.warn;
     const realPlatform = process.platform;
     beforeEach(function() {
       process.platform = 'linux';
@@ -115,10 +212,11 @@ describe('DependencyGraph', function() {
     });
 
     afterEach(function() {
+      console.warn = consoleWarn;
       process.platform = realPlatform;
     });
 
-    pit('should get dependencies', function() {
+    it('should get dependencies', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -186,7 +284,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should resolve relative entry path', function() {
+    it('should resolve relative entry path', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -219,7 +317,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get shallow dependencies', function() {
+    it('should get shallow dependencies', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -274,7 +372,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get dependencies with the correct extensions', function() {
+    it('should get dependencies with the correct extensions', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -328,7 +426,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get json dependencies', function() {
+    it('should get json dependencies', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -388,7 +486,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get package json as a dep', () => {
+    it('should get package json as a dep', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -435,7 +533,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get dependencies with deprecated assets', function() {
+    it('should get dependencies with deprecated assets', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -483,7 +581,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get dependencies with relative assets', function() {
+    it('should get dependencies with relative assets', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -533,7 +631,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get dependencies with assets and resolution', function() {
+    it('should get dependencies with assets and resolution', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -612,7 +710,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should respect platform extension in assets', function() {
+    it('should respect platform extension in assets', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -692,7 +790,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('Deprecated and relative assets can live together', function() {
+    it('Deprecated and relative assets can live together', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -754,7 +852,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should get recursive dependencies', function() {
+    it('should get recursive dependencies', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -804,7 +902,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with packages', function() {
+    it('should work with packages', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -855,7 +953,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with packages', function() {
+    it('should work with packages', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -906,7 +1004,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with packages with a dot in the name', function() {
+    it('should work with packages with a dot in the name', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -975,7 +1073,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should default main package to index.js', function() {
+    it('should default main package to index.js', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1020,7 +1118,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should resolve using alternative ids', () => {
+    it('should resolve using alternative ids', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1069,7 +1167,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should default use index.js if main is a dir', function() {
+    it('should default use index.js if main is a dir', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1117,7 +1215,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should resolve require to index if it is a dir', function() {
+    it('should resolve require to index if it is a dir', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1162,7 +1260,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should resolve require to main if it is a dir w/ a package.json', function() {
+    it('should resolve require to main if it is a dir w/ a package.json', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1211,7 +1309,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should ignore malformed packages', function() {
+    it('should ignore malformed packages', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1248,8 +1346,9 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should fatal on multiple modules with the same name', function() {
+    it('should fatal on multiple modules with the same name', function() {
-      var root = '/root';
+      const root = '/root';
+      console.warn = jest.fn();
       setMockFileSystem({
         'root': {
           'index.js': [
@@ -1279,10 +1378,11 @@ describe('DependencyGraph', function() {
           'with the same name across two different files.'
         );
         expect(err.type).toEqual('DependencyGraphError');
+        expect(console.warn).toBeCalled();
       });
     });
 
-    pit('should be forgiving with missing requires', function() {
+    it('should be forgiving with missing requires', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1317,7 +1417,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with packages with subdirs', function() {
+    it('should work with packages with subdirs', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1373,7 +1473,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with packages with symlinked subdirs', function() {
+    it('should work with packages with symlinked subdirs', function() {
       var root = '/root';
       setMockFileSystem({
         'symlinkedPackage': {
@@ -1430,7 +1530,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with relative modules in packages', function() {
+    it('should work with relative modules in packages', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -1522,7 +1622,7 @@ describe('DependencyGraph', function() {
     }
 
     function testBrowserField(fieldName) {
-      pit('should support simple browser field in packages ("' + fieldName + '")', function() {
+      it('should support simple browser field in packages ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1577,7 +1677,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser field in packages w/o .js ext ("' + fieldName + '")', function() {
+      it('should support browser field in packages w/o .js ext ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1630,7 +1730,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support mapping main in browser field json ("' + fieldName + '")', function() {
+      it('should support mapping main in browser field json ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1686,7 +1786,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should work do correct browser mapping w/o js ext ("' + fieldName + '")', function() {
+      it('should work do correct browser mapping w/o js ext ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1744,7 +1844,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser mapping of files ("' + fieldName + '")', function() {
+      it('should support browser mapping of files ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1848,7 +1948,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser mapping for packages ("' + fieldName + '")', function() {
+      it('should support browser mapping for packages ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1920,7 +2020,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser mapping of a package to a file ("' + fieldName + '")', () => {
+      it('should support browser mapping of a package to a file ("' + fieldName + '")', () => {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -1999,7 +2099,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser mapping for packages ("' + fieldName + '")', function() {
+      it('should support browser mapping for packages ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -2071,7 +2171,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser exclude of a package ("' + fieldName + '")', function() {
+      it('should support browser exclude of a package ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -2128,7 +2228,7 @@ describe('DependencyGraph', function() {
         });
       });
 
-      pit('should support browser exclude of a file ("' + fieldName + '")', function() {
+      it('should support browser exclude of a file ("' + fieldName + '")', function() {
         var root = '/root';
         setMockFileSystem({
           'root': {
@@ -2181,7 +2281,7 @@ describe('DependencyGraph', function() {
       });
     }
 
-    pit('should fall back to browser mapping from react-native mapping', function() {
+    it('should fall back to browser mapping from react-native mapping', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -2273,7 +2373,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with absolute paths', () => {
+    it('should work with absolute paths', () => {
       const root = '/root';
       setMockFileSystem({
         [root.slice(1)]: {
@@ -2313,7 +2413,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should merge browser mapping with react-native mapping', function() {
+    it('should merge browser mapping with react-native mapping', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -2451,7 +2551,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should fall back to `extraNodeModules`', () => {
+    it('should fall back to `extraNodeModules`', () => {
       const root = '/root';
       setMockFileSystem({
         [root.slice(1)]: {
@@ -2513,7 +2613,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit(
+    it(
       'should only use `extraNodeModules` after checking all possible filesystem locations',
       () => {
         const root = '/root';
@@ -2561,7 +2661,7 @@ describe('DependencyGraph', function() {
       }
     );
 
-    pit('should be able to resolve paths within `extraNodeModules`', () => {
+    it('should be able to resolve paths within `extraNodeModules`', () => {
       const root = '/root';
       setMockFileSystem({
         [root.slice(1)]: {
@@ -2692,7 +2792,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with absolute paths', () => {
+    it('should work with absolute paths', () => {
       const root = 'C:\\root';
       setMockFileSystem({
         'root': {
@@ -2745,7 +2845,7 @@ describe('DependencyGraph', function() {
       process.platform = realPlatform;
     });
 
-    pit('should work with nested node_modules', function() {
+    it('should work with nested node_modules', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -2835,7 +2935,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('platform should work with node_modules', function() {
+    it('platform should work with node_modules', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -2905,7 +3005,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('nested node_modules with specific paths', function() {
+    it('nested node_modules with specific paths', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -2996,7 +3096,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('nested node_modules with browser field', function() {
+    it('nested node_modules with browser field', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3091,7 +3191,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('node_modules should support multi level', function() {
+    it('node_modules should support multi level', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3165,7 +3265,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should selectively ignore providesModule in node_modules', function() {
+    it('should selectively ignore providesModule in node_modules', function() {
       var root = '/root';
       var otherRoot = '/anotherRoot';
       setMockFileSystem({
@@ -3339,7 +3439,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should not be confused by prev occuring whitelisted names', function() {
+    it('should not be confused by prev occuring whitelisted names', function() {
       var root = '/react-haste';
       setMockFileSystem({
         'react-haste': {
@@ -3397,7 +3497,7 @@ describe('DependencyGraph', function() {
     });
 
 
-    pit('should ignore modules it cant find (assumes own require system)', function() {
+    it('should ignore modules it cant find (assumes own require system)', function() {
       // For example SourceMap.js implements it's own require system.
       var root = '/root';
       setMockFileSystem({
@@ -3441,7 +3541,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with node packages with a .js in the name', function() {
+    it('should work with node packages with a .js in the name', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3494,7 +3594,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with multiple platforms (haste)', function() {
+    it('should work with multiple platforms (haste)', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3553,7 +3653,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should pick the generic file', function() {
+    it('should pick the generic file', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3613,7 +3713,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with multiple platforms (node)', function() {
+    it('should work with multiple platforms (node)', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3660,7 +3760,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should require package.json', () => {
+    it('should require package.json', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3741,7 +3841,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with one-character node_modules', () => {
+    it('should work with one-character node_modules', () => {
       const root = '/root';
       setMockFileSystem({
         [root.slice(1)]: {
@@ -3796,7 +3896,7 @@ describe('DependencyGraph', function() {
 
     const DependencyGraph = require('../index');
 
-    pit('should work with nested node_modules', function() {
+    it('should work with nested node_modules', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3886,7 +3986,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('platform should work with node_modules', function() {
+    it('platform should work with node_modules', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -3956,7 +4056,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('nested node_modules with specific paths', function() {
+    it('nested node_modules with specific paths', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4047,7 +4147,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('nested node_modules with browser field', function() {
+    it('nested node_modules with browser field', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4142,7 +4242,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('node_modules should support multi level', function() {
+    it('node_modules should support multi level', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4216,7 +4316,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should selectively ignore providesModule in node_modules', function() {
+    it('should selectively ignore providesModule in node_modules', function() {
       var root = '/root';
       var otherRoot = '/anotherRoot';
       setMockFileSystem({
@@ -4390,7 +4490,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should not be confused by prev occuring whitelisted names', function() {
+    it('should not be confused by prev occuring whitelisted names', function() {
       var root = '/react-haste';
       setMockFileSystem({
         'react-haste': {
@@ -4447,7 +4547,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should ignore modules it cant find (assumes own require system)', function() {
+    it('should ignore modules it cant find (assumes own require system)', function() {
       // For example SourceMap.js implements it's own require system.
       var root = '/root';
       setMockFileSystem({
@@ -4491,7 +4591,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with node packages with a .js in the name', function() {
+    it('should work with node packages with a .js in the name', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4544,7 +4644,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with multiple platforms (haste)', function() {
+    it('should work with multiple platforms (haste)', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4603,7 +4703,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should pick the generic file', function() {
+    it('should pick the generic file', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4662,7 +4762,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should work with multiple platforms (node)', function() {
+    it('should work with multiple platforms (node)', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4709,7 +4809,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should require package.json', () => {
+    it('should require package.json', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -4824,7 +4924,7 @@ describe('DependencyGraph', function() {
       process.platform = realPlatform;
     });
 
-    pit('updates module dependencies', function() {
+    it('updates module dependencies', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -4887,7 +4987,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('updates module dependencies on file change', function() {
+    it('updates module dependencies on file change', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -4950,7 +5050,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('updates module dependencies on file delete', function() {
+    it('updates module dependencies on file delete', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5012,7 +5112,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('updates module dependencies on file add', function() {
+    it('updates module dependencies on file add', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5105,7 +5205,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('updates module dependencies on deprecated asset add', function() {
+    it('updates module dependencies on deprecated asset add', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5174,7 +5274,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('updates module dependencies on relative asset add', function() {
+    it('updates module dependencies on relative asset add', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5244,7 +5344,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('runs changes through ignore filter', function() {
+    it('runs changes through ignore filter', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5334,7 +5434,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should ignore directory updates', function() {
+    it('should ignore directory updates', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5409,7 +5509,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('changes to browser field', function() {
+    it('changes to browser field', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5472,7 +5572,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('removes old package from cache', function() {
+    it('removes old package from cache', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5523,7 +5623,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should update node package changes', function() {
+    it('should update node package changes', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5629,7 +5729,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should update node package main changes', function() {
+    it('should update node package main changes', function() {
       var root = '/root';
       var filesystem = setMockFileSystem({
         'root': {
@@ -5694,7 +5794,7 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('should not error when the watcher reports a known file as added', function() {
+    it('should not error when the watcher reports a known file as added', function() {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5737,7 +5837,7 @@ describe('DependencyGraph', function() {
       process.platform = realPlatform;
     });
 
-    pit('supports custom file extensions', () => {
+    it('supports custom file extensions', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5808,7 +5908,7 @@ describe('DependencyGraph', function() {
       process.platform = realPlatform;
     });
 
-    pit('resolves to null if mocksPattern is not specified', () => {
+    it('resolves to null if mocksPattern is not specified', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5830,7 +5930,7 @@ describe('DependencyGraph', function() {
         });
     });
 
-    pit('retrieves a list of all required mocks', () => {
+    it('retrieves a list of all required mocks', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5863,7 +5963,7 @@ describe('DependencyGraph', function() {
         });
     });
 
-    pit('adds mocks as a dependency of their actual module', () => {
+    it('adds mocks as a dependency of their actual module', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -5936,7 +6036,7 @@ describe('DependencyGraph', function() {
         });
     });
 
-    pit('resolves mocks that do not have a real module associated with them', () => {
+    it('resolves mocks that do not have a real module associated with them', () => {
       var root = '/root';
       setMockFileSystem({
         'root': {
@@ -6035,20 +6135,20 @@ describe('DependencyGraph', function() {
       });
     });
 
-    pit('calls back for each finished module', () => {
+    it('calls back for each finished module', () => {
       return getDependencies().then(() =>
         expect(onProgress.mock.calls.length).toBe(8)
       );
     });
 
-    pit('increases the number of finished modules in steps of one', () => {
+    it('increases the number of finished modules in steps of one', () => {
       return getDependencies().then(() => {
         const increments = onProgress.mock.calls.map(([finished]) => finished);
         expect(increments).toEqual([1, 2, 3, 4, 5, 6, 7, 8]);
       });
     });
 
-    pit('adds the number of discovered modules to the number of total modules', () => {
+    it('adds the number of discovered modules to the number of total modules', () => {
       return getDependencies().then(() => {
         const increments = onProgress.mock.calls.map(([, total]) => total);
         expect(increments).toEqual([3, 5, 6, 6, 7, 7, 8, 8]);
@@ -6062,7 +6162,7 @@ describe('DependencyGraph', function() {
       DependencyGraph = require('../index');
     });
 
-    pit('allows setting dependencies for asset modules', () => {
+    it('allows setting dependencies for asset modules', () => {
       const assetDependencies = ['arbitrary', 'dependencies'];
 
       setMockFileSystem({
@@ -6121,7 +6221,7 @@ describe('DependencyGraph', function() {
         roots: ['/root'],
       });
       moduleReadDeferreds = {};
-      callDeferreds = [defer()/* a.js */, defer()/* b.js */];
+      callDeferreds = [defer(), defer()]; // [a.js, b.js]
 
       Module.prototype.read = jest.genMockFn().mockImplementation(function() {
         const returnValue = moduleRead.apply(this, arguments);
@@ -6143,7 +6243,7 @@ describe('DependencyGraph', function() {
       Module.prototype.read = moduleRead;
     });
 
-    pit('produces a deterministic tree if the "a" module resolves first', () => {
+    it('produces a deterministic tree if the "a" module resolves first', () => {
       const dependenciesPromise = getOrderedDependenciesAsJSON(dependencyGraph, 'index.js');
 
       return Promise.all(callDeferreds.map(deferred => deferred.promise))
@@ -6168,7 +6268,7 @@ describe('DependencyGraph', function() {
         });
     });
 
-    pit('produces a deterministic tree if the "b" module resolves first', () => {
+    it('produces a deterministic tree if the "b" module resolves first', () => {
       const dependenciesPromise = getOrderedDependenciesAsJSON(dependencyGraph, 'index.js');
 
       return Promise.all(callDeferreds.map(deferred => deferred.promise))

packager/react-packager/src/node-haste/__tests__/Module-test.js

@@ -78,17 +78,16 @@ describe('Module', () => {
   const createJSONModule =
     (options) => createModule({...options, file: '/root/package.json'});
 
-  beforeEach(function(done) {
+  beforeEach(function() {
     process.platform = 'linux';
     cache = createCache();
     fastfs = new Fastfs(
       'test',
       ['/root'],
       fileWatcher,
-      {crawling: Promise.resolve([fileName, '/root/package.json']), ignore: []},
+      ['/root/index.js', '/root/package.json'],
+      {ignore: []},
     );
-
-    fastfs.build().then(done);
   });
 
   describe('Module ID', () => {

packager/react-packager/src/node-haste/__tests__/fastfs-integrated-test.js

@@ -22,13 +22,17 @@ const contents = fs.readFileSync(fileName, 'utf-8');
 
 describe('fastfs:', function() {
   let fastfs;
-  const crawling = Promise.resolve([fileName]);
   const roots = [__dirname];
   const watcher = new EventEmitter();
 
-  beforeEach(function(done) {
+  beforeEach(function() {
-    fastfs = new Fastfs('arbitrary', roots, watcher, {crawling});
+    fastfs = new Fastfs(
-    fastfs.build().then(done);
+      'arbitrary',
+      roots,
+      watcher,
+      [`${__dirname}/fastfs-data`],
+      {}
+    );
   });
 
   describe('partial reading', () => {

packager/react-packager/src/node-haste/crawlers/index.js

@@ -1,13 +0,0 @@
-'use strict';
-
-const nodeCrawl = require('./node');
-const watchmanCrawl = require('./watchman');
-
-function crawl(roots, options) {
-  const {fileWatcher} = options;
-  return (fileWatcher ? fileWatcher.isWatchman() : Promise.resolve(false)).then(
-    isWatchman => isWatchman ? watchmanCrawl(roots, options) : nodeCrawl(roots, options)
-  );
-}
-
-module.exports = crawl;

packager/react-packager/src/node-haste/crawlers/node.js

@@ -1,61 +0,0 @@
-'use strict';
-
-const denodeify = require('denodeify');
-const debug = require('debug')('ReactNativePackager:DependencyGraph');
-const fs = require('graceful-fs');
-const path = require('../fastpath');
-
-const readDir = denodeify(fs.readdir);
-const stat = denodeify(fs.stat);
-
-function nodeRecReadDir(roots, {ignore, exts}) {
-  const queue = roots.slice();
-  const retFiles = [];
-  const extPattern = new RegExp(
-    '\.(' + exts.join('|') + ')$'
-  );
-
-  function search() {
-    const currDir = queue.shift();
-    if (!currDir) {
-      return Promise.resolve();
-    }
-
-    return readDir(currDir)
-      .then(files => files.map(f => path.join(currDir, f)))
-      .then(files => Promise.all(
-        files.map(f => stat(f).catch(handleBrokenLink))
-      ).then(stats => [
-        // Remove broken links.
-        files.filter((file, i) => !!stats[i]),
-        stats.filter(Boolean),
-      ]))
-      .then(([files, stats]) => {
-        files.forEach((filePath, i) => {
-          if (ignore(filePath)) {
-            return;
-          }
-
-          if (stats[i].isDirectory()) {
-            queue.push(filePath);
-            return;
-          }
-
-          if (filePath.match(extPattern)) {
-            retFiles.push(path.resolve(filePath));
-          }
-        });
-
-        return search();
-      });
-  }
-
-  return search().then(() => retFiles);
-}
-
-function handleBrokenLink(e) {
-  debug('WARNING: error stating, possibly broken symlink', e.message);
-  return Promise.resolve();
-}
-
-module.exports = nodeRecReadDir;

packager/react-packager/src/node-haste/crawlers/watchman.js

@@ -1,76 +0,0 @@
-'use strict';
-
-const denodeify = require('denodeify');
-const path = require('../fastpath');
-
-const watchmanURL = 'https://facebook.github.io/watchman/docs/troubleshooting.html';
-
-function watchmanRecReadDir(roots, {ignore, fileWatcher, exts}) {
-  const files = [];
-  return Promise.all(
-    roots.map(
-      root => fileWatcher.getWatcherForRoot(root)
-    )
-  ).then(
-    watchers => {
-      // All watchman roots for all watches we have.
-      const watchmanRoots = watchers.map(
-        watcher => watcher.watchProjectInfo.root
-      );
-
-      // Actual unique watchers (because we use watch-project we may end up with
-      // duplicate "real" watches, and that's by design).
-      // TODO(amasad): push this functionality into the `FileWatcher`.
-      const uniqueWatchers = watchers.filter(
-        (watcher, i) => watchmanRoots.indexOf(watcher.watchProjectInfo.root) === i
-      );
-
-      return Promise.all(
-        uniqueWatchers.map(watcher => {
-          const watchedRoot = watcher.watchProjectInfo.root;
-
-          // Build up an expression to filter the output by the relevant roots.
-          const dirExpr = ['anyof'];
-          for (let i = 0; i < roots.length; i++) {
-            const root = roots[i];
-            if (isDescendant(watchedRoot, root)) {
-              dirExpr.push(['dirname', path.relative(watchedRoot, root)]);
-            }
-          }
-
-          const cmd = denodeify(watcher.client.command.bind(watcher.client));
-          return cmd(['query', watchedRoot, {
-            suffix: exts,
-            expression: ['allof', ['type', 'f'], 'exists', dirExpr],
-            fields: ['name'],
-          }]).then(resp => {
-            if ('warning' in resp) {
-              console.warn('watchman warning: ', resp.warning);
-            }
-
-            resp.files.forEach(filePath => {
-              filePath = watchedRoot + path.sep + filePath;
-              if (!ignore(filePath)) {
-                files.push(filePath);
-              }
-              return false;
-            });
-          });
-        })
-      );
-    }).then(
-      () => files,
-      error => {
-        throw new Error(
-          `Watchman error: ${error.message.trim()}. Make sure watchman ` +
-          `is running for this project. See ${watchmanURL}.`
-        );
-      }
-    );
-}
-
-function isDescendant(root, child) {
-  return root === child || child.startsWith(root + path.sep);
-}
-
-module.exports = watchmanRecReadDir;

packager/react-packager/src/node-haste/fastfs.js

@@ -20,7 +20,7 @@ const stat = denodeify(fs.stat);
 const NOT_FOUND_IN_ROOTS = 'NotFoundInRootsError';
 
 class Fastfs extends EventEmitter {
-  constructor(name, roots, fileWatcher, {ignore, crawling, activity}) {
+  constructor(name, roots, fileWatcher, files, {ignore, activity}) {
     super();
     this._name = name;
     this._fileWatcher = fileWatcher;
@@ -37,45 +37,39 @@ class Fastfs extends EventEmitter {
       return new File(root, true);
     });
     this._fastPaths = Object.create(null);
-    this._crawling = crawling;
     this._activity = activity;
-  }
 
-  build() {
+    let fastfsActivity;
-    return this._crawling.then(files => {
+    if (activity) {
-      let fastfsActivity;
+      fastfsActivity = activity.startEvent(
-      const activity = this._activity;
+        'Building in-memory fs for ' + this._name,
-      if (activity) {
+        null,
-        fastfsActivity = activity.startEvent(
+        {
-          'Building in-memory fs for ' + this._name,
+          telemetric: true,
-          null,
+        },
-          {
+      );
-            telemetric: true,
+    }
-          },
+    files.forEach(filePath => {
-        );
+      const root = this._getRoot(filePath);
-      }
+      if (root) {
-      files.forEach(filePath => {
+        const newFile = new File(filePath, false);
-        const root = this._getRoot(filePath);
+        const dirname = filePath.substr(0, filePath.lastIndexOf(path.sep));
-        if (root) {
+        const parent = this._fastPaths[dirname];
-          const newFile = new File(filePath, false);
+        this._fastPaths[filePath] = newFile;
-          const dirname = filePath.substr(0, filePath.lastIndexOf(path.sep));
+        if (parent) {
-          const parent = this._fastPaths[dirname];
+          parent.addChild(newFile, this._fastPaths);
-          this._fastPaths[filePath] = newFile;
+        } else {
-          if (parent) {
+          root.addChild(newFile, this._fastPaths);
-            parent.addChild(newFile, this._fastPaths);
-          } else {
-            root.addChild(newFile, this._fastPaths);
-          }
         }
-      });
-      if (activity) {
-        activity.endEvent(fastfsActivity);
-      }
-
-      if (this._fileWatcher) {
-        this._fileWatcher.on('all', this._processFileChange.bind(this));
       }
     });
+    if (activity) {
+      activity.endEvent(fastfsActivity);
+    }
+
+    if (this._fileWatcher) {
+      this._fileWatcher.on('all', this._processFileChange.bind(this));
+    }
   }
 
   stat(filePath) {

packager/react-packager/src/node-haste/index.js

@@ -11,10 +11,10 @@
 const Cache = require('./Cache');
 const Fastfs = require('./fastfs');
 const FileWatcher = require('./FileWatcher');
+const JestHasteMap = require('jest-haste-map');
 const Module = require('./Module');
 const ModuleCache = require('./ModuleCache');
 const Polyfill = require('./Polyfill');
-const crawl = require('./crawlers');
 const extractRequires = require('./lib/extractRequires');
 const getAssetDataFromName = require('./lib/getAssetDataFromName');
 const getInverseDependencies = require('./lib/getInverseDependencies');
@@ -23,6 +23,7 @@ const isAbsolutePath = require('absolute-path');
 const replacePatterns = require('./lib/replacePatterns');
 const path = require('./fastpath');
 const util = require('util');
+const os = require('os');
 const DependencyGraphHelpers = require('./DependencyGraph/DependencyGraphHelpers');
 const ResolutionRequest = require('./DependencyGraph/ResolutionRequest');
 const ResolutionResponse = require('./DependencyGraph/ResolutionResponse');
@@ -57,6 +58,10 @@ class DependencyGraph {
     assetDependencies,
     moduleOptions,
     extraNodeModules,
+    // additional arguments for jest-haste-map
+    useWatchman,
+    maxWorkers,
+    resetCache,
   }) {
     this._opts = {
       activity: activity || defaultActivity,
@@ -78,6 +83,10 @@ class DependencyGraph {
         cacheTransformResults: true,
       },
       extraNodeModules,
+      // additional arguments for jest-haste-map & defaults
+      useWatchman: useWatchman !== false,
+      maxWorkers,
+      resetCache,
     };
     this._cache = cache;
     this._assetDependencies = assetDependencies;
@@ -90,103 +99,110 @@ class DependencyGraph {
       return this._loading;
     }
 
-    const {activity} = this._opts;
+    const mw = this._opts.maxWorkers;
-    const depGraphActivity = activity.startEvent(
+    const haste = new JestHasteMap({
-      'Initializing Packager',
+      extensions: this._opts.extensions.concat(this._opts.assetExts),
-      null,
+      ignorePattern: {test: this._opts.ignoreFilePath},
-      {
+      maxWorkers: typeof mw === 'number' && mw >= 1 ? mw : getMaxWorkers(),
-        telemetric: true,
+      mocksPattern: '',
-      },
+      name: 'react-native-packager',
-    );
+      platforms: Array.from(this._opts.platforms),
-    const crawlActivity = activity.startEvent(
+      providesModuleNodeModules: this._opts.providesModuleNodeModules,
-      'Crawling File System',
+      resetCache: this._opts.resetCache,
-      null,
+      retainAllFiles: true,
-      {
+      roots: this._opts.roots.concat(this._opts.assetRoots_DEPRECATED),
-        telemetric: true,
+      useWatchman: this._opts.useWatchman,
-      },
-    );
-    const allRoots = this._opts.roots.concat(this._opts.assetRoots_DEPRECATED);
-    this._crawling = crawl(allRoots, {
-      ignore: this._opts.ignoreFilePath,
-      exts: this._opts.extensions.concat(this._opts.assetExts),
-      fileWatcher: this._opts.fileWatcher,
-    });
-    this._crawling.then((files) => activity.endEvent(crawlActivity));
-
-    this._fastfs = new Fastfs(
-      'JavaScript',
-      this._opts.roots,
-      this._opts.fileWatcher,
-      {
-        ignore: this._opts.ignoreFilePath,
-        crawling: this._crawling,
-        activity: activity,
-      }
-    );
-
-    this._fastfs.on('change', this._processFileChange.bind(this));
-
-    this._moduleCache = new ModuleCache({
-      fastfs: this._fastfs,
-      cache: this._cache,
-      extractRequires: this._opts.extractRequires,
-      transformCode: this._opts.transformCode,
-      depGraphHelpers: this._helpers,
-      assetDependencies: this._assetDependencies,
-      moduleOptions: this._opts.moduleOptions,
-    }, this._opts.platforms);
-
-    this._hasteMap = new HasteMap({
-      fastfs: this._fastfs,
-      extensions: this._opts.extensions,
-      moduleCache: this._moduleCache,
-      preferNativePlatform: this._opts.preferNativePlatform,
-      helpers: this._helpers,
-      platforms: this._opts.platforms,
     });
 
-    this._deprecatedAssetMap = new DeprecatedAssetMap({
+    this._loading = haste.build().then(hasteMap => {
-      fsCrawl: this._crawling,
+      const {activity} = this._opts;
-      roots: this._opts.assetRoots_DEPRECATED,
+      const depGraphActivity = activity.startEvent(
-      helpers: this._helpers,
+        'Initializing Packager',
-      fileWatcher: this._opts.fileWatcher,
+        null,
-      ignoreFilePath: this._opts.ignoreFilePath,
+        {
-      assetExts: this._opts.assetExts,
+          telemetric: true,
-      activity: this._opts.activity,
+        },
-      enabled: this._opts.enableAssetMap,
+      );
-      platforms: this._opts.platforms,
-    });
 
-    this._loading = Promise.all([
+      const hasteFSFiles = hasteMap.hasteFS.getAllFiles();
-      this._fastfs.build()
+
-        .then(() => {
+      this._fastfs = new Fastfs(
-          const hasteActivity = activity.startEvent(
+        'JavaScript',
-            'Building Haste Map',
+        this._opts.roots,
-            null,
+        this._opts.fileWatcher,
-            {
+        hasteFSFiles,
-              telemetric: true,
+        {
-            },
+          ignore: this._opts.ignoreFilePath,
+          activity: activity,
+        }
+      );
+
+      this._fastfs.on('change', this._processFileChange.bind(this));
+
+      this._moduleCache = new ModuleCache({
+        fastfs: this._fastfs,
+        cache: this._cache,
+        extractRequires: this._opts.extractRequires,
+        transformCode: this._opts.transformCode,
+        depGraphHelpers: this._helpers,
+        assetDependencies: this._assetDependencies,
+        moduleOptions: this._opts.moduleOptions,
+      }, this._opts.platforms);
+
+      this._hasteMap = new HasteMap({
+        fastfs: this._fastfs,
+        extensions: this._opts.extensions,
+        moduleCache: this._moduleCache,
+        preferNativePlatform: this._opts.preferNativePlatform,
+        helpers: this._helpers,
+        platforms: this._opts.platforms,
+      });
+
+      const escapePath = (p: string) => {
+        return (path.sep === '\\')  ? p.replace(/(\/|\\(?!\.))/g, '\\\\') : p;
+      };
+
+      const assetPattern =
+        new RegExp('^' + this._opts.assetRoots_DEPRECATED.map(escapePath).join('|'));
+
+      const assetFiles = hasteMap.hasteFS.matchFiles(assetPattern);
+
+      this._deprecatedAssetMap = new DeprecatedAssetMap({
+        helpers: this._helpers,
+        assetExts: this._opts.assetExts,
+        platforms: this._opts.platforms,
+        files: assetFiles,
+      });
+
+      this._fastfs.on('change', (type, filePath, root, fstat) => {
+        if (assetPattern.test(path.join(root, filePath))) {
+          this._deprecatedAssetMap.processFileChange(type, filePath, root, fstat);
+        }
+      });
+
+      const hasteActivity = activity.startEvent(
+        'Building Haste Map',
+        null,
+        {
+          telemetric: true,
+        },
+      );
+      return this._hasteMap.build().then(
+        map => {
+          activity.endEvent(hasteActivity);
+          activity.endEvent(depGraphActivity);
+          return map;
+        },
+        err => {
+          const error = new Error(
+            `Failed to build DependencyGraph: ${err.message}`
           );
-          return this._hasteMap.build().then(map => {
+          error.type = ERROR_BUILDING_DEP_GRAPH;
-            activity.endEvent(hasteActivity);
+          error.stack = err.stack;
-            return map;
+          throw error;
-          });
+        }
-        }),
+      );
-      this._deprecatedAssetMap.build(),
+    });
-    ]).then(
-      response => {
-        activity.endEvent(depGraphActivity);
-        return response[0]; // Return the haste map
-      },
-      err => {
-        const error = new Error(
-          `Failed to build DependencyGraph: ${err.message}`
-        );
-        error.type = ERROR_BUILDING_DEP_GRAPH;
-        error.stack = err.stack;
-        throw error;
-      }
-    );
 
     return this._loading;
   }
@@ -312,7 +328,7 @@ class DependencyGraph {
         this._loading = this._hasteMap.build();
       } else {
         this._loading = this._hasteMap.processFileChange(type, absPath);
-        this._loading.catch((e) => this._hasteMapError = e);
+        this._loading.catch((e) => {this._hasteMapError = e;});
       }
       return this._loading;
     };
@@ -351,4 +367,28 @@ function NotFoundError() {
 }
 util.inherits(NotFoundError, Error);
 
+function getMaxWorkers() {
+  const cores = os.cpus().length;
+
+  if (cores <= 1) {
+    // oh well...
+    return 1;
+  }
+  if (cores <= 4) {
+    // don't starve the CPU while still reading reasonably rapidly
+    return cores - 1;
+  }
+  if (cores <= 8) {
+    // empirical testing showed massive diminishing returns when going over
+    // 4 or 5 workers on 8-core machines
+    return Math.floor(cores * 0.75) - 1;
+  }
+
+  // pretty much guesswork
+  if (cores < 24) {
+    return Math.floor(3 / 8 * cores + 3);
+  }
+  return cores / 2;
+}
+
 module.exports = DependencyGraph;