I'm a web developer with an Android smartphone and Ubuntu as my main OS, Windows as my secondary.

My primary means of testing on iOS/Safari is to be very careful about which features I target by checking caniuse.com and the JS compatibility list. And that doesn't protect you against iOS randomly doing something stupid like pretending to give you access to localStorage in private browsing mode but actually write everything to /dev/null instead.

Luckily Safari has one fourth the userbase so it's a little easier to ignore them.