One unfortunate thing about localStorage is that if you start using it, and then decide to move instead to IndexDB (or WebSQL, or the Filesystem API), you need

One unfortunate thing about localStorage is that if you start using it, and then decide to move instead to IndexDB (or WebSQL, or the Filesystem API), you need to jump the chasm from synchronous to asynchronous. Which in Javascript always means a hefty rewrite, since there's no way to abstract out async vs sync. It makes me long for call-with-current-continuation.