From d016b2e9e45c64eef7cded65cccaedd2212133a0 Mon Sep 17 00:00:00 2001
From: Lukas Piatkowski <luk@fb.com>
Date: Wed, 3 May 2017 03:45:04 -0700
Subject: [PATCH] Add additional post process of SourceMap after the
 minification of JS

Reviewed By: davidaurelio

Differential Revision: D4955229

fbshipit-source-id: ac4e5f917839d43d73b80d98b4813d8ccf1d41ef
---
 packages/metro-bundler/react-packager.js     | 3 ++-
 packages/metro-bundler/src/Bundler/index.js  | 8 ++++++++
 packages/metro-bundler/src/Resolver/index.js | 6 +++++-
 packages/metro-bundler/src/Server/index.js   | 5 ++++-
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/packages/metro-bundler/react-packager.js b/packages/metro-bundler/react-packager.js
index 36459e85..079b42ac 100644
--- a/packages/metro-bundler/react-packager.js
+++ b/packages/metro-bundler/react-packager.js
@@ -17,7 +17,7 @@ const debug = require('debug');
 const invariant = require('fbjs/lib/invariant');
 
 import type Server from './src/Server';
-import type {PostProcessModules} from './src/Bundler';
+import type {PostProcessModules, PostMinifyProcess} from './src/Bundler';
 import type {GlobalTransformCache} from './src/lib/GlobalTransformCache';
 import type {Reporter} from './src/lib/reporting';
 import type {HasteImpl} from './src/node-haste/Module';
@@ -30,6 +30,7 @@ type Options = {
   globalTransformCache: ?GlobalTransformCache,
   nonPersistent?: boolean,
   postProcessModules?: PostProcessModules,
+  postMinifyProcess?: PostMinifyProcess,
   projectRoots: Array<string>,
   reporter?: Reporter,
   watch?: boolean,
diff --git a/packages/metro-bundler/src/Bundler/index.js b/packages/metro-bundler/src/Bundler/index.js
index d9d652bd..32b38c2e 100644
--- a/packages/metro-bundler/src/Bundler/index.js
+++ b/packages/metro-bundler/src/Bundler/index.js
@@ -40,6 +40,7 @@ const VERSION = require('../../package.json').version;
 import type AssetServer from '../AssetServer';
 import type Module, {HasteImpl} from '../node-haste/Module';
 import type ResolutionResponse from '../node-haste/DependencyGraph/ResolutionResponse';
+import type {MappingsMap} from '../lib/SourceMap';
 import type {Options as JSTransformerOptions} from '../JSTransformer/worker/worker';
 import type {Reporter} from '../lib/reporting';
 import type {GlobalTransformCache} from '../lib/GlobalTransformCache';
@@ -112,6 +113,11 @@ export type PostProcessModules = (
   options: PostProcessModulesOptions,
 ) => Array<ModuleTransport>;
 
+export type PostMinifyProcess = ({
+  code: string,
+  map: MappingsMap,
+}) => {code: string, map: MappingsMap};
+
 type Options = {|
   +allowBundleUpdates: boolean,
   +assetExts: Array<string>,
@@ -125,6 +131,7 @@ type Options = {|
   +platforms: Array<string>,
   +polyfillModuleNames: Array<string>,
   +postProcessModules?: PostProcessModules,
+  +postMinifyProcess?: PostMinifyProcess,
   +projectRoots: Array<string>,
   +providesModuleNodeModules?: Array<string>,
   +reporter: Reporter,
@@ -206,6 +213,7 @@ class Bundler {
       hasteImpl: opts.hasteImpl,
       maxWorkerCount,
       minifyCode: this._transformer.minify,
+      postMinifyProcess: this._opts.postMinifyProcess,
       platforms: new Set(opts.platforms),
       polyfillModuleNames: opts.polyfillModuleNames,
       projectRoots: opts.projectRoots,
diff --git a/packages/metro-bundler/src/Resolver/index.js b/packages/metro-bundler/src/Resolver/index.js
index f96ab082..11091396 100644
--- a/packages/metro-bundler/src/Resolver/index.js
+++ b/packages/metro-bundler/src/Resolver/index.js
@@ -19,6 +19,7 @@ const pathJoin = require('path').join;
 import type ResolutionResponse from '../node-haste/DependencyGraph/ResolutionResponse';
 import type Module, {HasteImpl, TransformCode} from '../node-haste/Module';
 import type {MappingsMap} from '../lib/SourceMap';
+import type {PostMinifyProcess} from '../Bundler';
 import type {Options as JSTransformerOptions} from '../JSTransformer/worker/worker';
 import type {Reporter} from '../lib/reporting';
 import type {GetTransformCacheKey} from '../lib/TransformCache';
@@ -38,6 +39,7 @@ type Options = {|
   +hasteImpl?: HasteImpl,
   +maxWorkerCount: number,
   +minifyCode: MinifyCode,
+  +postMinifyProcess?: PostMinifyProcess,
   +platforms: Set<string>,
   +polyfillModuleNames?: Array<string>,
   +projectRoots: Array<string>,
@@ -52,10 +54,12 @@ class Resolver {
 
   _depGraph: DependencyGraph;
   _minifyCode: MinifyCode;
+  _postMinifyProcess: ?PostMinifyProcess;
   _polyfillModuleNames: Array<string>;
 
   constructor(opts: Options, depGraph: DependencyGraph) {
     this._minifyCode = opts.minifyCode;
+    this._postMinifyProcess = opts.postMinifyProcess;
     this._polyfillModuleNames = opts.polyfillModuleNames || [];
     this._depGraph = depGraph;
   }
@@ -222,7 +226,7 @@ class Resolver {
     }
 
     return minify
-      ? this._minifyCode(module.path, code, map)
+      ? this._minifyCode(module.path, code, map).then(this._postMinifyProcess)
       : Promise.resolve({code, map});
   }
 
diff --git a/packages/metro-bundler/src/Server/index.js b/packages/metro-bundler/src/Server/index.js
index d4e832cc..b450506c 100644
--- a/packages/metro-bundler/src/Server/index.js
+++ b/packages/metro-bundler/src/Server/index.js
@@ -32,7 +32,7 @@ import type ResolutionResponse from '../node-haste/DependencyGraph/ResolutionRes
 import type Bundle from '../Bundler/Bundle';
 import type HMRBundle from '../Bundler/HMRBundle';
 import type {Reporter} from '../lib/reporting';
-import type {GetTransformOptions, PostProcessModules} from '../Bundler';
+import type {GetTransformOptions, PostProcessModules, PostMinifyProcess} from '../Bundler';
 import type {GlobalTransformCache} from '../lib/GlobalTransformCache';
 import type {SourceMap, Symbolicate} from './symbolicate';
 
@@ -68,6 +68,7 @@ type Options = {
   platforms?: Array<string>,
   polyfillModuleNames?: Array<string>,
   postProcessModules?: PostProcessModules,
+  postMinifyProcess?: PostMinifyProcess,
   projectRoots: Array<string>,
   providesModuleNodeModules?: Array<string>,
   reporter: Reporter,
@@ -122,6 +123,7 @@ class Server {
     platforms: Array<string>,
     polyfillModuleNames: Array<string>,
     postProcessModules?: PostProcessModules,
+    postMinifyProcess?: PostMinifyProcess,
     projectRoots: Array<string>,
     providesModuleNodeModules?: Array<string>,
     reporter: Reporter,
@@ -158,6 +160,7 @@ class Server {
       platforms: options.platforms || defaults.platforms,
       polyfillModuleNames: options.polyfillModuleNames || [],
       postProcessModules: options.postProcessModules,
+      postMinifyProcess: options.postMinifyProcess,
       projectRoots: options.projectRoots,
       providesModuleNodeModules: options.providesModuleNodeModules,
       reporter: options.reporter,