In the orbit of you : a novel / Ashley Schumacher.

Enhanced descriptions from Syndetics:

In the Orbit of You is a YA story of enduring love from acclaimed author Ashley Schumacher, where a personality test reunites two friends and makes them second guess their careful plans.

It's been years since Nova Evans last saw Sam. She was too young then to understand why he had to move away--and what it had to do with the cuts and bruises he got from home and never wanted to talk about. All she knew is that they promised to find each other when they were older, something she thought was impossible thanks to her and her mom moving around constantly. Until she bumps into Sam in her new school, and realizes he has clearly forgotten their childhood promise.

Sam Jordan has a plan for his life: accept his college football scholarship, date his girlfriend Abigail, and--most importantly--hide how much he wants to do something, anything other than The Plan(tm) his parents and coaches have set before him. It doesn't matter if sometimes he finds himself thinking about the new girl he met in the cafeteria, a girl who reminds him of a past that hurts to remember.

When a school-wide personality test reveals Nova and Sam to be each others' top matches--not only that, but a match of 99%, the highest in the school--they begin to remember why they were such close friends, all those years ago. As well as the myriad of reasons this new-yet-familiar, magnetic, sparkling thing between them will never, ever work out.

In the Orbit of You is a story about the enduring and changing nature of friendship, of the strange struggle between who you are and who you want to be, and finding your voice after trauma.