“use strict” from EcmaScript 5 is supported in WebStorm / PhpStorm!
Recently JavaScript specification was incrementally advanced with: a) common coding pitfalls prevention mode (aka “strict mode“) and b) nice (yet de-facto already used) existing library additions. With several browsers around the corner completely supporting new-but-backward-compatible standard we are HAPPY to announce that WebStorm 2.0 (and PhpStorm 2.0 too) will help YOU to use these new productive stuff! The good news is that when your code uses “use strict” (example on the left), the editor will mark as ERRORS all that accesses of undefined global variables, duplicated parameters / property names, using with statements, using delete operator for unqualified variables, octal integer constants and more. As to standard library additions, all that new Object/Array members should have been suggested for latest EAP version users. What is new is that editor knows about fields defined with methods like Object.defineProperty, e.g. as on example screenshot below. 
We are waiting for EAP version feedback. Develop your JavaScript with more pleasure!
