The Buffer.toString() you implemented just screwed things up by recursing until the stack was blown :)
I've renamed the zinter/zunion commands. All tests pass with latest redis-git.
The utf8Slice etc. functions really shouldn't be called anymore since they are not a part of the public API (atleast not documented). I'll be converting them later.
ZINTER, ZUNION -> ZINTERSTORE, ZUNIONSTORE
Remove custom Buffer.toString.
It leads to infinite recursion and utf8Slice seems to
be deprecated now
Redis >= 2.1.3 accepts double expiration set
It is now called so