add app.isPackaged (#12656)

* add isPackaged method

* add false test case for app.isPackaged()

* document add.isPackaged()

* check isPackaged() without fs call

* convert to non-method property

* document app.isPackaged as a property

* update tests for app.isPackaged

* remove unused fs require

* clarify docs for isPackaged()

docs/api/app.md

@@ -1131,6 +1131,12 @@ Sets the application's [dock menu][dock-menu].
 
 Sets the `image` associated with this dock icon.
 
+## Properties
+
+### `app.isPackaged`
+
+A `Boolean` property that returns  `true` if the app is packaged, `false` otherwise. For many apps, this property can be used to distinguish development and production environments.
+
 [dock-menu]:https://developer.apple.com/library/mac/documentation/Carbon/Conceptual/customizing_docktile/concepts/dockconcepts.html#//apple_ref/doc/uid/TP30000986-CH2-TPXREF103
 [tasks]:https://msdn.microsoft.com/en-us/library/windows/desktop/dd378460(v=vs.85).aspx#tasks
 [app-user-model-id]: https://msdn.microsoft.com/en-us/library/windows/desktop/dd378459(v=vs.85).aspx

lib/browser/api/app.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const bindings = process.atomBinding('app')
+const path = require('path')
 const {app, App} = bindings
 
 // Only one app object permitted.
@@ -57,6 +58,14 @@ Object.assign(app, {
   }
 })
 
+app.isPackaged = (() => {
+  const execFile = path.basename(process.execPath).toLowerCase()
+  if (process.platform === 'win32') {
+    return execFile !== 'electron.exe'
+  }
+  return execFile !== 'electron'
+})()
+
 if (process.platform === 'darwin') {
   app.dock = {
     bounce (type = 'informational') {

spec/api-app-spec.js

@@ -118,6 +118,12 @@ describe('app module', () => {
     })
   })
 
+  describe('app.isPackaged', () => {
+    it('should be false durings tests', () => {
+      assert.equal(app.isPackaged, false)
+    })
+  })
+
   describe('app.isInApplicationsFolder()', () => {
     before(function () {
       if (process.platform !== 'darwin') {