[WA] I recently got a Job offer from a CRH Company & have to take a pre employment drug test (NonDOT- NONSafety Sensitive).

So I recently got a Job offer from a “CRH Company” & have to take a pre employment drug test, I’m not sure if they drug test for THC but I only smoke on weekends so I know I won’t pass if they do. So my Question ares:

Should I ask if they drug test for THC? If so should I let them know ahead of time that I won’t pass or should I just take the test?