packager: Resolver: make the Resolver construction a Promise

Reviewed By: cpojer

Differential Revision: D4681614

fbshipit-source-id: 5da558280edf300f67042e72c65b272e49351871

packages/metro-bundler/src/Bundler/__tests__/Bundler-test.js

@@ -86,6 +86,7 @@ describe('Bundler', function() {
         getModuleSystemDependencies,
       };
     });
+    Resolver.load = jest.fn().mockImplementation(opts => Promise.resolve(new Resolver(opts)));
 
     fs.statSync.mockImplementation(function() {
       return {

packages/metro-bundler/src/Bundler/index.js

@@ -108,7 +108,7 @@ class Bundler {
   _getModuleId: (opts: Module) => number;
   _cache: Cache;
   _transformer: Transformer;
-  _resolver: Resolver;
+  _resolverPromise: Promise<Resolver>;
   _projectRoots: Array<string>;
   _assetServer: AssetServer;
   _getTransformOptions: void | GetTransformOptions;
@@ -169,7 +169,7 @@ class Bundler {
       return transformCacheKey + getCacheKey(src, filename, options);
     };
 
-    this._resolver = new Resolver({
+    this._resolverPromise = Resolver.load({
       assetExts: opts.assetExts,
       blacklistRE: opts.blacklistRE,
       cache: this._cache,
@@ -204,9 +204,9 @@ class Bundler {
     this._transformer.kill();
     return Promise.all([
       this._cache.end(),
-      this.getResolver().getDependencyGraph().then(dependencyGraph => {
-        dependencyGraph.getWatcher().end();
-      }),
+      this._resolverPromise.then(
+        resolver => resolver.getDependencyGraph().getWatcher().end(),
+      ),
     ]);
   }
 
@@ -215,15 +215,15 @@ class Bundler {
     minify: boolean,
     unbundle: boolean,
     sourceMapUrl: string,
-  }) {
+  }): Promise<Bundle> {
     const {dev, minify, unbundle} = options;
-    const moduleSystemDeps =
-      this._resolver.getModuleSystemDependencies({dev, unbundle});
-    return this._bundle({
+    return this._resolverPromise.then(
+      resolver => resolver.getModuleSystemDependencies({dev, unbundle}),
+    ).then(moduleSystemDeps => this._bundle({
       ...options,
       bundle: new Bundle({dev, minify, sourceMapUrl: options.sourceMapUrl}),
       moduleSystemDeps,
-    });
+    }));
   }
 
   _sourceHMRURL(platform: ?string, hmrpath: string) {
@@ -338,11 +338,11 @@ class Bundler {
       response: ResolutionResponse,
       modulesByName: {[name: string]: Module},
     }) =>
-      Promise.all(
+      this._resolverPromise.then(resolver => Promise.all(
         transformedModules.map(({module, transformed}) =>
-          finalBundle.addModule(this._resolver, response, module, transformed)
+          finalBundle.addModule(resolver, response, module, transformed)
         )
-      ).then(() => {
+      )).then(() => {
         const runBeforeMainModuleIds = Array.isArray(runBeforeMainModule)
           ? runBeforeMainModule
               .map(name => modulesByName[name])
@@ -415,7 +415,9 @@ class Bundler {
       });
     }
 
-    return Promise.resolve(resolutionResponse).then(response => {
+    return Promise.all(
+      [this._resolverPromise, resolutionResponse],
+    ).then(([resolver, response]) => {
       bundle.setRamGroups(response.transformOptions.transform.ramGroups);
 
       log(createActionEndEntry(transformingFilesLogEntry));
@@ -425,7 +427,7 @@ class Bundler {
       let entryFilePath;
       if (response.dependencies.length > 1) { // skip HMR requests
         const numModuleSystemDependencies =
-          this._resolver.getModuleSystemDependencies({dev, unbundle}).length;
+          resolver.getModuleSystemDependencies({dev, unbundle}).length;
 
         const dependencyIndex =
           (response.numPrependedDependencies || 0) + numModuleSystemDependencies;
@@ -501,12 +503,14 @@ class Bundler {
         transform: transformSpecificOptions,
       };
 
-      return this._resolver.getShallowDependencies(entryFile, transformOptions);
+      return this._resolverPromise.then(
+        resolver => resolver.getShallowDependencies(entryFile, transformOptions),
+      );
     });
   }
 
-  getModuleForPath(entryFile: string) {
-    return this._resolver.getModuleForPath(entryFile);
+  getModuleForPath(entryFile: string): Promise<Module> {
+    return this._resolverPromise.then(resolver => resolver.getModuleForPath(entryFile));
   }
 
   getDependencies({
@@ -547,13 +551,13 @@ class Bundler {
         transform: transformSpecificOptions,
       };
 
-      return this._resolver.getDependencies(
+      return this._resolverPromise.then(resolver => resolver.getDependencies(
         entryFile,
         {dev, platform, recursive},
         transformOptions,
         onProgress,
         isolateModuleIDs ? createModuleIdFactory() : this._getModuleId,
-      );
+      ));
     });
   }
 
@@ -771,8 +775,8 @@ class Bundler {
       });
   }
 
-  getResolver() {
-    return this._resolver;
+  getResolver(): Promise<Resolver> {
+    return this._resolverPromise;
   }
 }
 

packages/metro-bundler/src/Resolver/__tests__/Resolver-test.js

@@ -39,7 +39,9 @@ describe('Resolver', function() {
       return polyfill;
     });
 
-    DependencyGraph.load = jest.fn().mockImplementation(opts => Promise.resolve(new DependencyGraph(opts)));
+    DependencyGraph.load = jest.fn().mockImplementation(
+      opts => Promise.resolve(new DependencyGraph(opts)),
+    );
     DependencyGraph.replacePatterns = require.requireActual('../../node-haste/lib/replacePatterns');
     DependencyGraph.prototype.createPolyfill = jest.fn();
     DependencyGraph.prototype.getDependencies = jest.fn();
@@ -101,8 +103,8 @@ describe('Resolver', function() {
 
       DependencyGraph.prototype.getDependencies.mockImplementation(
         () => Promise.reject());
-      return new Resolver({projectRoot: '/root'})
-        .getDependencies(entry, {platform}, transformOptions)
+      return Resolver.load({projectRoot: '/root'})
+        .then(r => r.getDependencies(entry, {platform}, transformOptions))
         .catch(() => {
           expect(DependencyGraph.prototype.getDependencies).toBeCalledWith({
             entryPath: entry,
@@ -114,19 +116,23 @@ describe('Resolver', function() {
     });
 
     it('passes custom platforms to the dependency graph', function() {
-      new Resolver({ // eslint-disable-line no-new
+      expect.assertions(1);
+      return Resolver.load({ // eslint-disable-line no-new
         projectRoot: '/root',
         platforms: ['ios', 'windows', 'vr'],
+      }).then(() => {
+        const platforms = DependencyGraph.mock.calls[0][0].platforms;
+        expect(Array.from(platforms)).toEqual(['ios', 'windows', 'vr']);
       });
-      const platforms = DependencyGraph.mock.calls[0][0].platforms;
-      expect(Array.from(platforms)).toEqual(['ios', 'windows', 'vr']);
     });
 
     it('should get dependencies with polyfills', function() {
+      expect.assertions(5);
+
       var module = createModule('index');
       var deps = [module];
 
-      var depResolver = new Resolver({
+      var depResolverPromise = Resolver.load({
         projectRoot: '/root',
       });
 
@@ -144,14 +150,14 @@ describe('Resolver', function() {
       };
       DependencyGraph.prototype.createPolyfill.mockReturnValueOnce(polyfill);
 
-      return depResolver
-        .getDependencies(
+      return depResolverPromise
+        .then(r => r.getDependencies(
           '/root/index.js',
           {dev: false},
           undefined,
           undefined,
           createGetModuleId()
-        ).then(function(result) {
+        )).then(function(result) {
           expect(result.mainModuleId).toEqual('index');
           expect(result.dependencies[result.dependencies.length - 1]).toBe(module);
 
@@ -256,10 +262,12 @@ describe('Resolver', function() {
     });
 
     it('should pass in more polyfills', function() {
+      expect.assertions(2);
+
       var module = createModule('index');
       var deps = [module];
 
-      var depResolver = new Resolver({
+      var depResolverPromise = Resolver.load({
         projectRoot: '/root',
         polyfillModuleNames: ['some module'],
       });
@@ -271,14 +279,14 @@ describe('Resolver', function() {
         }));
       });
 
-      return depResolver
-        .getDependencies(
+      return depResolverPromise
+        .then(r => r.getDependencies(
           '/root/index.js',
           {dev: false},
           undefined,
           undefined,
           createGetModuleId()
-        ).then(result => {
+        )).then(result => {
           expect(result.mainModuleId).toEqual('index');
           const calls =
             DependencyGraph.prototype.createPolyfill.mock.calls[result.dependencies.length - 2];
@@ -305,13 +313,14 @@ describe('Resolver', function() {
   describe('wrapModule', function() {
     let depResolver;
     beforeEach(() => {
-      depResolver = new Resolver({
-        depResolver,
+      return Resolver.load({
         projectRoot: '/root',
-      });
+      }).then(r => { depResolver = r; });
     });
 
     it('should resolve modules', function() {
+      expect.assertions(1);
+
       /*eslint-disable */
       var code = [
         // require
@@ -378,6 +387,8 @@ describe('Resolver', function() {
     });
 
     it('should add module transport names as fourth argument to `__d`', () => {
+      expect.assertions(1);
+
       const module = createModule('test module');
       const code = 'arbitrary(code)'
       const resolutionResponse = new ResolutionResponseMock({
@@ -400,6 +411,7 @@ describe('Resolver', function() {
     });
 
     it('should pass through passed-in source maps', () => {
+      expect.assertions(1);
       const module = createModule('test module');
       const resolutionResponse = new ResolutionResponseMock({
         dependencies: [module],
@@ -416,23 +428,25 @@ describe('Resolver', function() {
     });
 
     it('should resolve polyfills', function () {
-      const depResolver = new Resolver({
+      expect.assertions(1);
+      return Resolver.load({
         projectRoot: '/root',
-      });
-      const polyfill = createPolyfill('test polyfill', []);
-      const code = [
-        'global.fetch = () => 1;',
-      ].join('');
-      return depResolver.wrapModule({
-        module: polyfill,
-        code
-      }).then(({code: processedCode}) => {
-        expect(processedCode).toEqual([
-          '(function(global) {',
+      }).then(depResolver => {;
+        const polyfill = createPolyfill('test polyfill', []);
+        const code = [
           'global.fetch = () => 1;',
-          '\n})' +
-          "(typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : this);",
-        ].join(''));
+        ].join('');
+        return depResolver.wrapModule({
+          module: polyfill,
+          code
+        }).then(({code: processedCode}) => {
+          expect(processedCode).toEqual([
+            '(function(global) {',
+            'global.fetch = () => 1;',
+            '\n})' +
+            "(typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : this);",
+          ].join(''));
+        });
       });
     });
 
@@ -442,15 +456,18 @@ describe('Resolver', function() {
       let depResolver, module, resolutionResponse;
 
       beforeEach(() => {
-        depResolver = new Resolver({projectRoot: '/root'});
-        module = createJsonModule(id);
-        resolutionResponse = new ResolutionResponseMock({
-          dependencies: [module],
-          mainModuleId: id,
+        return Resolver.load({projectRoot: '/root'}).then(r => {
+          depResolver = r;
+          module = createJsonModule(id);
+          resolutionResponse = new ResolutionResponseMock({
+            dependencies: [module],
+            mainModuleId: id,
+          });
         });
       });
 
       it('should prefix JSON files with `module.exports=`', () => {
+        expect.assertions(1);
         return depResolver
           .wrapModule({resolutionResponse, module, name: id, code, dev: false})
           .then(({code: processedCode}) =>
@@ -469,10 +486,6 @@ describe('Resolver', function() {
       beforeEach(() => {
         minifyCode = jest.fn((filename, code, map) =>
           Promise.resolve({code, map}));
-        depResolver = new Resolver({
-          projectRoot: '/root',
-          minifyCode,
-        });
         module = createModule(id);
         module.path = '/arbitrary/path.js';
         resolutionResponse = new ResolutionResponseMock({
@@ -480,9 +493,14 @@ describe('Resolver', function() {
           mainModuleId: id,
         });
         sourceMap = {version: 3, sources: ['input'], mappings: 'whatever'};
+        return Resolver.load({
+          projectRoot: '/root',
+          minifyCode,
+        }).then(r => { depResolver = r; });
       });
 
       it('should invoke the minifier with the wrapped code', () => {
+        expect.assertions(1);
         const wrappedCode =
           `__d(/* ${id} */function(global, require, module, exports) {${
             code}\n}, ${resolutionResponse.getModuleId(module)});`
@@ -501,6 +519,7 @@ describe('Resolver', function() {
       });
 
       it('should use minified code', () => {
+        expect.assertions(2);
         const minifiedCode = 'minified(code)';
         const minifiedMap = {version: 3, file: ['minified']};
         minifyCode.mockReturnValue(Promise.resolve({code: minifiedCode, map: minifiedMap}));

packages/metro-bundler/src/Resolver/index.js

@@ -50,13 +50,18 @@ type Options = {
 
 class Resolver {
 
-  _depGraphPromise: Promise<DependencyGraph>;
   _depGraph: DependencyGraph;
   _minifyCode: MinifyCode;
   _polyfillModuleNames: Array<string>;
 
-  constructor(opts: Options) {
-    this._depGraphPromise = DependencyGraph.load({
+  constructor(opts: Options, depGraph: DependencyGraph) {
+    this._minifyCode = opts.minifyCode;
+    this._polyfillModuleNames = opts.polyfillModuleNames || [];
+    this._depGraph = depGraph;
+  }
+
+  static async load(opts: Options): Promise<Resolver> {
+    const depGraph = await DependencyGraph.load({
       assetDependencies: ['react-native/Libraries/Image/AssetRegistry'],
       assetExts: opts.assetExts,
       cache: opts.cache,
@@ -86,19 +91,7 @@ class Resolver {
       useWatchman: true,
       watch: opts.watch || false,
     });
-
-    this._minifyCode = opts.minifyCode;
-    this._polyfillModuleNames = opts.polyfillModuleNames || [];
-
-    this._depGraphPromise.then(
-      depGraph => { this._depGraph = depGraph; },
-      err => {
-        console.error(err.message + '\n' + err.stack);
-        // FIXME(jeanlauliac): we shall never exit the process by ourselves,
-        // packager may be used in a server application or the like.
-        process.exit(1);
-      },
-    );
+    return new Resolver(opts, depGraph);
   }
 
   getShallowDependencies(
@@ -120,13 +113,13 @@ class Resolver {
     getModuleId: mixed,
   ): Promise<ResolutionResponse> {
     const {platform, recursive = true} = options;
-    return this._depGraphPromise.then(depGraph => depGraph.getDependencies({
+    return this._depGraph.getDependencies({
       entryPath,
       platform,
       transformOptions,
       recursive,
       onProgress,
-    })).then(resolutionResponse => {
+    }).then(resolutionResponse => {
       this._getPolyfillDependencies().reverse().forEach(
         polyfill => resolutionResponse.prependDependency(polyfill)
       );
@@ -252,8 +245,8 @@ class Resolver {
     return this._minifyCode(path, code, map);
   }
 
-  getDependencyGraph(): Promise<DependencyGraph> {
-    return this._depGraphPromise;
+  getDependencyGraph(): DependencyGraph {
+    return this._depGraph;
   }
 }
 

packages/metro-bundler/src/Server/__tests__/Server-test.js

@@ -79,12 +79,12 @@ describe('processRequest', () => {
 
     Bundler.prototype.invalidateFile = invalidatorFunc;
     Bundler.prototype.getResolver =
-      jest.fn().mockReturnValue({
-        getDependencyGraph: jest.fn().mockReturnValue(Promise.resolve({
+      jest.fn().mockReturnValue(Promise.resolve({
+        getDependencyGraph: jest.fn().mockReturnValue({
           getHasteMap: jest.fn().mockReturnValue({on: jest.fn()}),
           load: jest.fn(() => Promise.resolve()),
-        })),
-      });
+        }),
+      }));
 
     server = new Server(options);
     requestHandler = server.processRequest.bind(server);

packages/metro-bundler/src/Server/index.js

@@ -251,8 +251,8 @@ class Server {
     this._bundler = new Bundler(bundlerOpts);
 
     // changes to the haste map can affect resolution of files in the bundle
-    this._bundler.getResolver().getDependencyGraph().then(dependencyGraph => {
-      dependencyGraph.getWatcher().on(
+    this._bundler.getResolver().then(resolver => {
+      resolver.getDependencyGraph().getWatcher().on(
         'change',
         ({eventsQueue}) => eventsQueue.forEach(processFileChange),
       );
@@ -306,7 +306,7 @@ class Server {
     entryFile: string,
     platform?: string,
   }): Promise<Bundle> {
-    return this._bundler.getResolver().getDependencyGraph().then(() => {
+    return this._bundler.getResolver().then(() => {
       if (!options.platform) {
         options.platform = getPlatformExtension(options.entryFile);
       }
@@ -319,13 +319,14 @@ class Server {
       bundleDeps.set(bundle, {
         files: new Map(
           nonVirtual
-            .map(({sourcePath, meta = {dependencies: []}}) =>
-              [sourcePath, meta.dependencies])
+            .map(({sourcePath, meta}) =>
+              [sourcePath, meta != null ? meta.dependencies : []])
         ),
         idToIndex: new Map(modules.map(({id}, i) => [id, i])),
         dependencyPairs: new Map(
           nonVirtual
             .filter(({meta}) => meta && meta.dependencyPairs)
+            /* $FlowFixMe: the filter above ensures `dependencyPairs` is not null. */
             .map(m => [m.sourcePath, m.meta.dependencyPairs])
         ),
         outdated: new Set(),
@@ -361,7 +362,7 @@ class Server {
     });
   }
 
-  getModuleForPath(entryFile: string): Module {
+  getModuleForPath(entryFile: string): Promise<Module> {
     return this._bundler.getModuleForPath(entryFile);
   }
 
@@ -602,8 +603,6 @@ class Server {
 
           debug('Attempt to update existing bundle');
 
-          const changedModules =
-            Array.from(outdated, this.getModuleForPath, this);
           // $FlowFixMe(>=0.37.0)
           deps.outdated = new Set();
 
@@ -615,11 +614,14 @@ class Server {
           // specific response we can compute a non recursive one which
           // is the least we need and improve performance.
           const bundlePromise = this._bundles[optionsJson] =
-            this.getDependencies({
-              platform, dev, hot, minify,
-              entryFile: options.entryFile,
-              recursive: false,
-            }).then(response => {
+            Promise.all([
+              this.getDependencies({
+                platform, dev, hot, minify,
+                entryFile: options.entryFile,
+                recursive: false,
+              }),
+              Promise.all(Array.from(outdated, this.getModuleForPath, this)),
+            ]).then(([response, changedModules]) => {
               debug('Update bundle: rebuild shallow bundle');
 
               changedModules.forEach(m => {
@@ -969,7 +971,7 @@ class Server {
   }
 }
 
-function contentsEqual(array: Array<mixed>, set: Set<mixed>): boolean {
+function contentsEqual<T>(array: Array<T>, set: Set<T>): boolean {
   return array.length === set.size && array.every(set.has, set);
 }
 

packages/metro-bundler/src/lib/ModuleTransport.js

@@ -17,6 +17,7 @@ import type {MixedSourceMap} from './SourceMap';
 type SourceMapOrMappings = MixedSourceMap | Array<RawMapping>;
 
 type Metadata = {
+  dependencies?: ?Array<string>,
   dependencyPairs?: Array<[mixed, {path: string}]>,
   preloaded?: boolean,
 };