In case someone is wondering, hair follicle tests are apparently problematic [1]; had to look that up because I remembered correctly that follicle tests can show use over the long-term, but didn't know some of the intrinsic challenges with that method. Come to think of it, I've never been asked to submit a hair sample when I've had to pass FBI interviews and drug tests to gain admittance to extremely-sensitive data centers at some of my clients in the past.
The "week or two" needs contextual guidance. An article on Wikipedia [2] gives a good run down of the detection periods. I would imagine detecting pot is the most common request, so that's about 100 days on the conservative side for a heavy (daily?) user, but apparently three weeks is fine for more casual users (what, once a week?).
[1] http://www.fleetowner.com/driver-management-resource-center/...
[2] https://en.wikipedia.org/wiki/Drug_test#Detection_periods
There's also the possibility that giving up an addiction is not an intellectual activity (if you think about it a little!)
But the process of getting addicted certainly involves making some choices poorly.
Addiction is continued use in the face of adverse consequences. [1] You may have a physical dependence on coffee, but it doesn't sound like you're experiencing negative consequences in your life from its use.
[1] https://www.addictioninfo.org/articles/2216/1/Addiction-Do-Y...
Look, you got one task, one task only, it's not even hard to figure out, do not, repeat, do not, get high the week or two before your pee test. That simple. There are human bipeds burning valuable oxygen right now, who can't follow a test that elaborate and complicated. They are literally the kind of people where if you told them not to lick a circuit breaker, would turn around and an hour later electrocute themselves and probably a coworker or two by licking a circuit breaker on the jobsite. Whats the minimum IQ and discipline level necessary to pass a pee test? Not much, but there are failures out there walking around...
Its interesting that as far as I know this is the first strictly chemistry based IQ test. AFAIK there is no "pee in a bottle to determine if you can fizzbuzz" test for code monkey work. No chemical marker that can identify if you know the modulus operator... not yet...