From eb489bf105552e07a45dbc4d4f7d469e06ab5b3a Mon Sep 17 00:00:00 2001
From: Rafael Oleza <rafeca@fb.com>
Date: Tue, 9 Jan 2018 17:40:47 -0800
Subject: [PATCH] Remove logic to calculate polyfills from Resolver

Reviewed By: jeanlauliac

Differential Revision: D6674424

fbshipit-source-id: 20c0ace056150c1f6910edc7eadf8effb9ddf38d
---
 .../src/DeltaBundler/DeltaTransformer.js      | 28 +++++++++------
 packages/metro/src/Resolver/index.js          | 34 +++----------------
 2 files changed, 23 insertions(+), 39 deletions(-)

diff --git a/packages/metro/src/DeltaBundler/DeltaTransformer.js b/packages/metro/src/DeltaBundler/DeltaTransformer.js
index f04ff2ae..620ac184 100644
--- a/packages/metro/src/DeltaBundler/DeltaTransformer.js
+++ b/packages/metro/src/DeltaBundler/DeltaTransformer.js
@@ -16,7 +16,9 @@ const DeltaCalculator = require('./DeltaCalculator');
 
 const addParamsToDefineCall = require('../lib/addParamsToDefineCall');
 const createModuleIdFactory = require('../lib/createModuleIdFactory');
+const defaults = require('../defaults');
 const nullthrows = require('fbjs/lib/nullthrows');
+const path = require('path');
 const removeInlineRequiresBlacklistFromOptions = require('../lib/removeInlineRequiresBlacklistFromOptions');
 
 const {EventEmitter} = require('events');
@@ -328,21 +330,17 @@ class DeltaTransformer extends EventEmitter {
       platform: this._bundleOptions.platform,
     }).concat(this._polyfillModuleNames);
 
-    // The module system dependencies are scripts that need to be included at
-    // the very beginning of the bundle (before any polyfill).
-    const moduleSystemDeps = this._resolver.getModuleSystemDependencies({
-      dev: this._bundleOptions.dev,
-    });
-
-    const modules = moduleSystemDeps.concat(
-      polyfillModuleNames.map((polyfillModuleName, idx) =>
+    // Build the module system dependencies (scripts that need to
+    // be included at the very beginning of the bundle) + any polifyll.
+    const modules = this._getModuleSystemDependencies()
+      .concat(polyfillModuleNames)
+      .map(polyfillModuleName =>
         this._resolver.getDependencyGraph().createPolyfill({
           file: polyfillModuleName,
           id: polyfillModuleName,
           dependencies: [],
         }),
-      ),
-    );
+      );
 
     return await this._transformModules(
       modules,
@@ -534,6 +532,16 @@ class DeltaTransformer extends EventEmitter {
   _onFileChange = () => {
     this.emit('change');
   };
+
+  _getModuleSystemDependencies() {
+    const prelude = this._bundleOptions.dev
+      ? path.resolve(__dirname, '../Resolver/polyfills/prelude_dev.js')
+      : path.resolve(__dirname, '../Resolver/polyfills/prelude.js');
+
+    const moduleSystem = defaults.moduleSystem;
+
+    return [prelude, moduleSystem];
+  }
 }
 
 module.exports = DeltaTransformer;
diff --git a/packages/metro/src/Resolver/index.js b/packages/metro/src/Resolver/index.js
index df2383ca..f979b996 100644
--- a/packages/metro/src/Resolver/index.js
+++ b/packages/metro/src/Resolver/index.js
@@ -14,26 +14,22 @@
 
 const DependencyGraph = require('../node-haste/DependencyGraph');
 
-const defaults = require('../defaults');
-
 const {
   compactMapping,
   fromRawMappings,
   toRawMappings,
 } = require('metro-source-map');
-const pathJoin = require('path').join;
 
-import type Module, {HasteImpl, TransformCode} from '../node-haste/Module';
-import type {CompactRawMappings} from '../lib/SourceMap';
 import type {PostMinifyProcess} from '../Bundler';
-import type {Reporter} from '../lib/reporting';
+import typeof {minify as MinifyCode} from '../JSTransformer/worker';
+import type {GlobalTransformCache} from '../lib/GlobalTransformCache';
+import type {CompactRawMappings} from '../lib/SourceMap';
 import type {
   TransformCache,
   GetTransformCacheKey,
 } from '../lib/TransformCaching';
-import type {GlobalTransformCache} from '../lib/GlobalTransformCache';
-
-import typeof {minify as MinifyCode} from '../JSTransformer/worker';
+import type {Reporter} from '../lib/reporting';
+import type {HasteImpl, TransformCode} from '../node-haste/Module';
 
 type Options = {|
   +assetExts: Array<string>,
@@ -61,16 +57,12 @@ type Options = {|
 
 class Resolver {
   _depGraph: DependencyGraph;
-  _getPolyfills: ({platform: ?string}) => $ReadOnlyArray<string>;
   _minifyCode: MinifyCode;
   _postMinifyProcess: PostMinifyProcess;
-  _polyfillModuleNames: Array<string>;
 
   constructor(opts: Options, depGraph: DependencyGraph) {
-    this._getPolyfills = opts.getPolyfills;
     this._minifyCode = opts.minifyCode;
     this._postMinifyProcess = opts.postMinifyProcess;
-    this._polyfillModuleNames = opts.polyfillModuleNames || [];
     this._depGraph = depGraph;
   }
 
@@ -100,22 +92,6 @@ class Resolver {
     return new Resolver(opts, depGraph);
   }
 
-  getModuleSystemDependencies({dev = true}: {dev?: boolean}): Array<Module> {
-    const prelude = dev
-      ? pathJoin(__dirname, 'polyfills/prelude_dev.js')
-      : pathJoin(__dirname, 'polyfills/prelude.js');
-
-    const moduleSystem = defaults.moduleSystem;
-
-    return [prelude, moduleSystem].map(moduleName =>
-      this._depGraph.createPolyfill({
-        file: moduleName,
-        id: moduleName,
-        dependencies: [],
-      }),
-    );
-  }
-
   async minifyModule(
     path: string,
     code: string,