Any good reputable roofer will give a 5-10 year workmanship guarantee on new roofs, and up to 20 years manufacturer’s warranty. Repairs are complicated to warrantee, it’s like trying to put a guarantee on a used tire, you just can’t.  Usually repairs are good for up to 1 year. You’ll know if the repair was done correctly after the first heavy downpour that comes. If the repaired area doesn’t leak, it likely will not again.