Packager postprocessing hook

Reviewed By: davidaurelio

Differential Revision: D5244060

fbshipit-source-id: 3f5f9ab9aeeb63eca13d6dab089c2bda42f70c33

local-cli/bundle/buildBundle.js

@@ -94,6 +94,7 @@ function buildBundle(
       platforms: defaultPlatforms.concat(platforms),
       postMinifyProcess: config.postMinifyProcess,
       postProcessModules: config.postProcessModules,
+      postProcessBundleSourcemap: config.postProcessBundleSourcemap,
       projectRoots: config.getProjectRoots(),
       providesModuleNodeModules: providesModuleNodeModules,
       resetCache: args.resetCache,

local-cli/util/Config.js

@@ -20,7 +20,13 @@ const {providesModuleNodeModules} = require('metro-bundler/src/defaults');
 
 const RN_CLI_CONFIG = 'rn-cli.config.js';
 
-import type {GetTransformOptions, PostMinifyProcess, PostProcessModules} from 'metro-bundler/src/Bundler';
+import type {
+  GetTransformOptions,
+  PostMinifyProcess,
+  PostProcessModules,
+  // $FlowFixMe: Exported by metro bundler
+  PostProcessBundleSourcemap
+} from 'metro-bundler/src/Bundler';
 import type {HasteImpl} from 'metro-bundler/src/node-haste/Module';
 import type {TransformVariants} from 'metro-bundler/src/ModuleGraph/types.flow';
 import type {PostProcessModules as PostProcessModulesForBuck} from 'metro-bundler/src/ModuleGraph/types.flow.js';
@@ -86,7 +92,7 @@ export type ConfigT = {
 
   /**
    * An optional function that can modify the code and source map of bundle
-   * after the minifaction took place.
+   * after the minifaction took place. (Function applied per module).
    */
   postMinifyProcess: PostMinifyProcess,
 
@@ -96,6 +102,13 @@ export type ConfigT = {
    */
   postProcessModules: PostProcessModules,
 
+  /**
+   * An optional function that can modify the code and source map of the bundle
+   * before it is written. Applied once for the entire bundle, only works if
+   * output is a plainBundle.
+   */
+  postProcessBundleSourcemap: PostProcessBundleSourcemap,
+
   /**
    * Same as `postProcessModules` but for the Buck worker. Eventually we do want
    * to unify both variants.
@@ -161,6 +174,7 @@ const Config = {
     postMinifyProcess: x => x,
     postProcessModules: modules => modules,
     postProcessModulesForBuck: modules => modules,
+    postProcessBundleSourcemap: ({code, map, outFileName}) => ({code, map}),
     transformVariants: () => ({default: {}}),
     getWorkerPath: () => null,
   }: ConfigT),