Thanks for pointing it out. It is still in development. The reason i was using CDN was because of bandwidth and reusing the cached JS if the user already has that.
What will be the best way to tackle this? If I put all those under one CDN then I guess the bandwidth problem will be solved but I wont be able to reuse the JS that user might already have. At the end of the day I still have to trust the third party JS.
The general consensus is that you won't (meaningfully) be able to "reuse the JS that a user might already have" anyway. The idea of well-know-domain.com/well-known-framework-well-known-version-0-1.js being cashed is interesting -- but a) it doesn't appear to work to well in practice (I seem to recall 30% hit rate for the "best case" of jquery-latest on some big CDN) b) It's not that much data anyway.
Lets say you have 500kb of compressed js. If you have 2 million unique visitors, that'll just eat 1TB of bandwidth -- and if you don't screw up your own cache headers -- that'll be that -- it'll be cached.