initial idea

atom/browser/api/lib/auto-updater/squirrel-update-win.coffee

@@ -0,0 +1,42 @@
+ChildProcess = require 'child_process'
+fs           = require 'fs'
+path         = require 'path'
+
+appFolder             = path.resolve(process.execPath, '..') # i.e. my-app/app-0.1.13/
+rootApplicationFolder = path.resolve(appFolder, '..') # i.e. my-app/
+updateDotExe          = path.join(rootApplicationFolder, 'Update.exe')
+exeName               = path.basename(process.execPath)
+
+# Spawn a command and invoke the callback when it completes with an error
+# and the output from standard out.
+spawn = (command, args, callback) ->
+  stdout = ''
+
+  try
+    spawnedProcess = ChildProcess.spawn(command, args)
+  catch error
+    # Spawn can throw an error
+    process.nextTick -> callback?(error, stdout)
+    return
+
+  spawnedProcess.stdout.on 'data', (data) -> stdout += data
+
+  error = null
+  spawnedProcess.on 'error', (processError) -> error ?= processError
+  spawnedProcess.on 'close', (code, signal) ->
+    error ?= new Error("Command failed: #{signal ? code}") if code isnt 0
+    error?.code ?= code
+    error?.stdout ?= stdout
+    callback?(error, stdout)
+
+# Spawn the Update.exe with the given arguments and invoke the callback when
+# the command completes.
+spawnUpdate = (args, callback) ->
+  spawn(updateDotExe, args, callback)
+
+# Exports
+exports.spawn = spawnUpdate
+
+# Is the Update.exe installed with Atom?
+exports.existsSync = ->
+  fs.accessSync(updateDotExe, fs.R_OK)