objective c - How to properly check iOS version controlling (from iOS 7.0) -

we developing project lot of functionality , module (call, chat, update feed , on). it's deployment target 7.0 latest. project has been developing since 2013. there lot of bugs , old code. project completed , ready release in app store.

but finding difficulties while testing qa. ios changes many things according it's version. struggling check these changes in different versions.

for example ios 8.3 facebook sharing have implemented own sdk. old slcomposeviewcontroller no more good. have take care of ios 8.3.

i wondering if somehow can list of these ios versions apple make changes, easier check project installing ios version in iphone. think type of information find in developer site. if kind of information helpful us.

thanks lot in advance.

i asked similar question couple years ago (not saying duplicate!), , got - "read documentation carefully". unfortunately still remains true now, can tools out.

for external libraries, recommend using either cocoapods or carthage. can specify versions want support , tools job check whether library want include compatible deployment targets.

for own code, have write xctests verify crucial parts of app or possibly whole codebase (testing ftw) , stick version checking. more zen in swift 2.0 you'll able api checking #available(ios 9.0) { ... }.