Hello, I have a hair follicile drug test coming up in a week or so and I took at the most 4 hits of weed in the beginning of last month I'm a non frequent user will I pass my test ?

Depends on what the parameters of the test. If they're testing for habitual use, i.e. daily, then probably not. If they're testing if you did it at all then maybe you will fail. It is what the threshold is set at.

What is the test for?

A hair drug test is meant to show consistent use over time. A 1.5 inch sample of hair, cut at the scalp line, will go back 90 days. Most likely you will be negative. If it is a test by an employer most employer use a hair drug test with higher cutoff levels so you should have no problem passing a basic hair drug test. Even if they use a limits of detection hair drug test with lower cutoff levels you should come up negative. 4 hits of weed just isn't enough to show up on a hair drug test.