Javascripr lets you put the binary operators in the next line if you want. It won't insert a semicolon there:

http://blog.izs.me/post/2353458699/an-open-letter-to-javascr...

I would say that the most common problem is having a semicolon not being inserted if you start a line with `(` or `[`. In practice, the only time when a semicolon gets inserted where it shouldn't is when returning an object literal.