What's the equivalent of "do shell script" with javascript automations? (Yosemite) Support for javascript automations started with Yosemite.

How could I run using javascript an external command? (i.e. the equivalent of do shell script of applescript?
If you look in the StandardAdditions.sdef.


Menubar menu: Windows -> Library 
Double click on: StandardAdditions
Change the dropdown to Javascript.


You will see that many of the script command change to the  camelHump syntax





app = Application.currentApplication()
app.includeStandardAdditions = true;

app.doShellScript('ls')