Reduce source map in 44.5 MiB for Nuclide

Reviewed By: pakoito, davidaurelio

Differential Revision: D5611240

fbshipit-source-id: b0090f6d07d3e08408fc27e91e462a2019130880

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

@@ -269,7 +269,7 @@ class Bundle extends BundleBase {
 
     return this._sourceMapFormat === 'indexed'
       ? this._getCombinedSourceMaps(options)
-      : fromRawMappings(this.getModules()).toMap();
+      : fromRawMappings(this.getModules()).toMap(undefined, options);
   }
 
   getSourceMapString(options: {excludeSource?: boolean}): string {
@@ -284,7 +284,10 @@ class Bundle extends BundleBase {
     let map = this._sourceMap;
     if (map == null) {
       debug('Start building flat source map');
-      map = this._sourceMap = fromRawMappings(this.getModules()).toString();
+      map = this._sourceMap = fromRawMappings(this.getModules()).toString(
+        undefined,
+        options,
+      );
       debug('End building flat source map');
     } else {
       debug('Returning cached source map');

packages/metro-bundler/src/Bundler/source-map/Generator.js

@@ -149,12 +149,20 @@ class Generator {
   /**
    * Return the source map as object.
    */
-  toMap(file?: string): MappingsMap {
+  toMap(file?: string, options: {excludeSource?: boolean}): MappingsMap {
+    let content;
+
+    if (options && options.excludeSource) {
+      content = {};
+    } else {
+      content = {sourcesContent: this.sourcesContent.slice()};
+    }
+
     return {
       version: 3,
       file,
       sources: this.sources.slice(),
-      sourcesContent: this.sourcesContent.slice(),
+      ...content,
       names: this.names.items(),
       mappings: this.builder.toString(),
     };
@@ -165,13 +173,21 @@ class Generator {
    *
    * This is ~2.5x faster than calling `JSON.stringify(generator.toMap())`
    */
-  toString(file?: string): string {
+  toString(file?: string, options: {excludeSource?: boolean}): string {
+    let content;
+
+    if (options && options.excludeSource) {
+      content = '';
+    } else {
+      content = `"sourcesContent":${JSON.stringify(this.sourcesContent)},`;
+    }
+
     return (
       '{' +
       '"version":3,' +
       (file ? `"file":${JSON.stringify(file)},` : '') +
       `"sources":${JSON.stringify(this.sources)},` +
-      `"sourcesContent":${JSON.stringify(this.sourcesContent)},` +
+      content +
       `"names":${JSON.stringify(this.names.items())},` +
       `"mappings":"${this.builder.toString()}"` +
       '}'

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

@@ -5,6 +5,8 @@
  * This source code is licensed under the BSD-style license found in the
  * LICENSE file in the root directory of this source tree. An additional grant
  * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @emails oncall+javascript_tools
  */
 
 'use strict';
@@ -156,6 +158,7 @@ describe('processRequest', () => {
         dev: true,
         entryFile: 'index.ios.js',
         entryModuleOnly: false,
+        excludeSource: false,
         generateSourceMaps: false,
         hot: false,
         inlineSourceMap: false,
@@ -183,6 +186,7 @@ describe('processRequest', () => {
         dev: true,
         entryFile: 'index.js',
         entryModuleOnly: false,
+        excludeSource: false,
         generateSourceMaps: false,
         hot: false,
         inlineSourceMap: false,
@@ -210,6 +214,7 @@ describe('processRequest', () => {
         dev: true,
         entryFile: 'index.js',
         entryModuleOnly: false,
+        excludeSource: false,
         generateSourceMaps: false,
         hot: false,
         inlineSourceMap: false,
@@ -447,6 +452,7 @@ describe('processRequest', () => {
           dev: true,
           entryFile: 'foo file',
           entryModuleOnly: false,
+          excludeSource: false,
           generateSourceMaps: false,
           hot: false,
           inlineSourceMap: false,
@@ -466,13 +472,14 @@ describe('processRequest', () => {
 
   describe('buildBundleFromUrl(options)', () => {
     it('Calls the bundler with the correct args', () => {
-      return server.buildBundleFromUrl('/path/to/foo.bundle?dev=false&runModule=false')
+      return server.buildBundleFromUrl('/path/to/foo.bundle?dev=false&runModule=false&excludeSource=true')
         .then(() =>
           expect(Bundler.prototype.bundle).toBeCalledWith({
             assetPlugins: [],
             dev: false,
             entryFile: 'path/to/foo.js',
             entryModuleOnly: false,
+            excludeSource: true,
             generateSourceMaps: true,
             hot: false,
             inlineSourceMap: false,
@@ -483,7 +490,7 @@ describe('processRequest', () => {
             resolutionResponse: null,
             runBeforeMainModule: ['InitializeCore'],
             runModule: false,
-            sourceMapUrl: '/path/to/foo.map?dev=false&runModule=false',
+            sourceMapUrl: '/path/to/foo.map?dev=false&runModule=false&excludeSource=true',
             unbundle: false,
           })
         );

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

@@ -102,6 +102,7 @@ export type BundleOptions = {
   dev: boolean,
   entryFile: string,
   +entryModuleOnly: boolean,
+  +excludeSource: boolean,
   +generateSourceMaps: boolean,
   +hot: boolean,
   +inlineSourceMap: boolean,
@@ -790,6 +791,7 @@ class Server {
             log(createActionEndEntry(requestingBundleLogEntry));
           } else if (requestType === 'map') {
             const sourceMap = p.getSourceMapString({
+              excludeSource: options.excludeSource,
               minify: options.minify,
               dev: options.dev,
             });
@@ -879,6 +881,7 @@ class Server {
     );
     return building.then(p =>
       p.getSourceMap({
+        excludeSource: options.excludeSource,
         minify: options.minify,
         dev: options.dev,
       }),
@@ -994,6 +997,12 @@ class Server {
 
     const dev = this._getBoolOptionFromQuery(urlObj.query, 'dev', true);
     const minify = this._getBoolOptionFromQuery(urlObj.query, 'minify', false);
+    const excludeSource = this._getBoolOptionFromQuery(
+      urlObj.query,
+      'excludeSource',
+      false,
+    );
+
     return {
       sourceMapUrl: url.format({
         hash: urlObj.hash,
@@ -1004,6 +1013,7 @@ class Server {
       entryFile,
       dev,
       minify,
+      excludeSource,
       hot: this._getBoolOptionFromQuery(urlObj.query, 'hot', false),
       runBeforeMainModule: defaults.runBeforeMainModule,
       runModule: this._getBoolOptionFromQuery(urlObj.query, 'runModule', true),
@@ -1054,6 +1064,7 @@ Server.DEFAULT_BUNDLE_OPTIONS = {
   assetPlugins: [],
   dev: true,
   entryModuleOnly: false,
+  excludeSource: false,
   generateSourceMaps: false,
   hot: false,
   inlineSourceMap: false,