I went through a recruiter for a job.
Went on the interview, got through the entire process.
The company wanted to hire me.  
The recruiter verbally went through the ENTIRE offer with me including
benefits etc.  All was good, I accepted.  I resigned from my current
job.
The next day the recruiter promised that the hiring company would send
me something official via email and the details would just be a hard
copy of what we discussed on the phone.
Got the official letter and it indicated drug testing was mandatory.

Should they have disclosed this much earlier in the process?  and do i
have any rights?

thank you

#1.  Never quit a job until you are actually hired and have a start
date with the new employer.

#2.  Most jobs that area position of trust use drug testing.  That
should not be news to anyone.

#3.  Rights?  You weren't even hired by the company yet.

hi daniel2d, i actually established a start date with the employer but
you are right, i probalby should have waited to give notice.

in terms of rights, the recruiter and i verbally agreed to the offer,
it was quite official.  it is her mistake that she didn't know about
drug testing.

are there any labor laws that mandate company's disclose this
information much earlier in the process and not after a candidate has
accepted the offer?

The applicable labor laws will depend on what state you're in, but
employers are pretty much allowed to implement any drug testing
policies they choose unless they're governed by a private agreement
(such as an employment contract or a union agreement) that says
otherwise. They can decide to drug test you or not as they see fit,
and in the states I'm aware of, they don't have to give you any
advance notice of a pre-employment drug test. You should check the
laws in your state for more specific information.