Add --indexed-unbundle flag to force iOS ra-bundle format

Summary: This adds a new flag to the `unbundle` command: `--indexed-unbundle` allows to output the indexed file format even when building for android.

Reviewed By: cpojer

Differential Revision: D4189485

fbshipit-source-id: e56192456de764eb38c25b574ceaaf52eb8a6fca

local-cli/bundle/output/unbundle/index.js

@@ -23,7 +23,7 @@ function saveUnbundle(bundle, options, log) {
   // we fork here depending on the platform:
   // while android is pretty good at loading individual assets, ios has a large
   // overhead when reading hundreds pf assets from disk
-  return options.platform === 'android' ?
+  return options.platform === 'android' && !options.indexedUnbundle ?
     asAssets(bundle, options, log) :
     asIndexedFile(bundle, options, log);
 }

local-cli/bundle/unbundle.js

@@ -23,5 +23,9 @@ module.exports = {
   name: 'unbundle',
   description: 'builds javascript as "unbundle" for offline use',
   func: unbundle,
-  options: bundleCommandLineArgs,
+  options: bundleCommandLineArgs.concat({
+    command: '--indexed-unbundle',
+    description: 'Force indexed unbundle file format, even when building for android',
+    default: false,
+  }),
 };