Embed setup bundle for preload scripts in sandboxed renderers.

Add a gyp target that creates a browserify bundle starting with
`lib/sandboxed_renderer/init.js`, which is embedded into the executable using
the `atom_js2c` target.

The goal of this bundle is to provide a very basic environment for preload
scripts where a `require` function is available.

electron.gyp

@@ -423,11 +423,44 @@
         },
       ],
     },  # target atom_js2c_copy
+    {
+      'target_name': 'atom_browserify',
+      'type': 'none',
+      'dependencies': [
+        # depend on this target to ensure the '<(js2c_input_dir)' is created
+        'atom_js2c_copy',
+      ],
+      'actions': [
+        {
+          'action_name': 'atom_browserify',
+          'inputs': [
+            '<@(browserify_entries)',
+            # Any js file under `lib/` can be included in the preload bundle.
+            # Add all js sources as dependencies so any change to a js file will
+            # trigger a rebuild of the bundle(and consequently of js2c).
+            '<@(js_sources)',
+          ],
+          'outputs': [
+            '<(js2c_input_dir)/preload_bundle.js',
+          ],
+          'action': [
+            'npm',
+            'run',
+            'browserify',
+            '--',
+            '<@(browserify_entries)',
+            '-o',
+            '<@(_outputs)',
+          ],
+        }
+      ],
+    },  # target atom_browserify
     {
       'target_name': 'atom_js2c',
       'type': 'none',
       'dependencies': [
         'atom_js2c_copy',
+        'atom_browserify',
       ],
       'actions': [
         {
@@ -435,6 +468,7 @@
           'inputs': [
             # List all input files that should trigger a rebuild with js2c
             '<@(js2c_sources)',
+            '<(js2c_input_dir)/preload_bundle.js',
           ],
           'outputs': [
             '<(SHARED_INTERMEDIATE_DIR)/atom_natives.h',

filenames.gypi

@@ -70,6 +70,9 @@
       'lib/renderer/extensions/storage.js',
       'lib/renderer/extensions/web-navigation.js',
     ],
+    'browserify_entries': [
+      'lib/sandboxed_renderer/init.js',
+    ],
     'js2c_sources': [
       'lib/common/asar.js',
       'lib/common/asar_init.js',

lib/sandboxed_renderer/init.js

@@ -0,0 +1,56 @@
+/* eslint no-eval: "off" */
+/* global binding, preloadPath, process, Buffer */
+const events = require('events')
+
+const ipcRenderer = new events.EventEmitter()
+const proc = new events.EventEmitter()
+// eval in window scope:
+// http://www.ecma-international.org/ecma-262/5.1/#sec-10.4.2
+const geval = eval
+
+require('../renderer/api/ipc-renderer-setup')(ipcRenderer, binding)
+
+binding.onMessage = function (channel, args) {
+  ipcRenderer.emit.apply(ipcRenderer, [channel].concat(args))
+}
+
+binding.onExit = function () {
+  proc.emit('exit')
+}
+
+const preloadModules = new Map([
+  ['electron', {
+    ipcRenderer: ipcRenderer
+  }]
+])
+
+function preloadRequire (module) {
+  if (preloadModules.has(module)) {
+    return preloadModules.get(module)
+  }
+  throw new Error('module not found')
+}
+
+// Fetch the source for the preload
+let preloadSrc = ipcRenderer.sendSync('ELECTRON_BROWSER_READ_FILE', preloadPath)
+if (preloadSrc.err) {
+  throw new Error(preloadSrc.err)
+}
+
+// Wrap the source into a function receives a `require` function as argument.
+// Browserify bundles can make use of this, as explained in:
+// https://github.com/substack/node-browserify#multiple-bundles
+//
+// For example, the user can create a browserify bundle with:
+//
+//     $ browserify -x electron preload.js > renderer.js
+//
+// and any `require('electron')` calls in `preload.js` will work as expected
+// since browserify won't try to include `electron` in the bundle and will fall
+// back to the `preloadRequire` function above.
+let preloadWrapperSrc = `(function(require, process, Buffer, global) {
+${preloadSrc.data}
+})`
+
+let preloadFn = geval(preloadWrapperSrc)
+preloadFn(preloadRequire, proc, Buffer, global)

package.json

@@ -3,6 +3,7 @@
   "version": "1.4.1",
   "devDependencies": {
     "asar": "^0.11.0",
+    "browserify": "^13.1.0",
     "electabul": "~0.0.4",
     "electron-docs-linter": "^1.6.2",
     "request": "*",
@@ -25,6 +26,7 @@
   "private": true,
   "scripts": {
     "bootstrap": "python ./script/bootstrap.py",
+    "browserify": "browserify",
     "build": "python ./script/build.py -c D",
     "clean": "python ./script/clean.py",
     "coverage": "npm run instrument-code-coverage && npm test -- --use-instrumented-asar",

script/bootstrap.py

@@ -14,10 +14,7 @@ SOURCE_ROOT = os.path.abspath(os.path.dirname(os.path.dirname(__file__)))
 VENDOR_DIR = os.path.join(SOURCE_ROOT, 'vendor')
 PYTHON_26_URL = 'https://chromium.googlesource.com/chromium/deps/python_26'
 
-if os.environ.has_key('CI'):
-  NPM = os.path.join(SOURCE_ROOT, 'node_modules', '.bin', 'npm')
-else:
-  NPM = 'npm'
+NPM = 'npm'
 if sys.platform in ['win32', 'cygwin']:
   NPM += '.cmd'
 

script/cibuild

@@ -65,6 +65,11 @@ def main():
   execute([npm, 'install', 'npm@2.12.1'])
 
   log_versions()
+  # Add "./node_modules/.bin" to the beginning of $PATH, which will ensure
+  # future "npm" invocations use the right version.
+  node_bin_dir = os.path.join(SOURCE_ROOT, 'node_modules', '.bin')
+  os.environ['PATH'] = os.path.pathsep.join([node_bin_dir,
+                                             os.environ.get('PATH', '')])
 
   is_release = os.environ.has_key('ELECTRON_RELEASE')
   args = ['--target_arch=' + target_arch]