Proposal: onBefore hooks should not be handled synchronously

[christopherthielen]

We currently allow onBefore hooks to either synchronously return a HookResult a transition, or to return a promise. This was initially created to implement the synchronous $stateChangeStart polyfill.

However, having onBefore be handled differently than the other hooks has caused additional edge cases, and has been at the root of a number of reported bugs. It also increases the code size and complexity. My gut feel is that removing synchronous handling code will make transition hooks easier to reason about.

I propose that onBefore is handled as a normal async hook, very similar to onStart hooks. It seems most likely that any end users who currently use onBefore will be unaware of the change in implementation.

[christopherthielen]

Closed by 30b82aa