Normally, Fibers have key or index which we'll use to match things up between reloads. However, roots don't have such a concept. We'll use their insertion order as an approximation. If it's consistent, we'll be able to restore the selection.
This implements the infrastructure for saving and restoring renderer-specific selection state in the session storage.
Note this doesn't actually implement the calculation and tracking of paths in the renderer. It only simulates that the renderer can do it. The actual implementation will come in a later commit.
Bugfix for `inferPriorityFromExpirationTime` function. It happened to
work in our existing tests because we use virtual time.
Flow would have caught this if expiration times were an opaque type. We
should consider that in the future. (The downside of opaque types is
that all operations would have to go through helper functions, which may
or may not get inlined by Closure.)
Fixes a bug where the timeout passed to `scheduleCallback` represented
an absolute timestamp, instead of the amount of time until that
timestamp is reached. The solution is to subtract the current time
from the expiration.
The bug wasn't caught by other tests because we use virtual times that
default to 0, and most tests don't advance time.
I also moved the `initialTimeMs` offset to the
`SchedulerWithReactIntegration` module so that we don't have to remember
to subtract the offset every time. (We should consider upstreaming this
to the Scheduler package.)
The implementation is wrong, but also it's not that useful for
debugging. Implementing it properly would involve tracking more
information than we do currently. Perhaps including the priority
of the callback in the message would be helpful, but not sure. For now
I'll just remove it.
This commit leaves a few major things uunresolved:
* We aren't yet polling for updates
* We aren't yet using the two setState pattern
* The resource cache will grow unbounded over time because we aren't yet clearing items from it
* The renderer interface is not smart enough to avoid resending unchanged data between requests