svelte

Commit Graph

Author	SHA1	Message	Date
Simon H	ce89035ecb	fix: prevent effect tree of batches from interfering with each other (#18508 ) While working on another Svelte feature I noticed a bug that boils down to batches interfering with each other through the effect tree: If batch A schedules an effect, it is walked up to the root (possibly). Now if in the meantime batch B also wants to schedule effects, it can have unintended consequences. Normally this does not happen, since it's extremely hard to run into this situation. There's basically two cases: Either an unfortunate timing of microtasks, or during flushing effects are scheduling new effects which messes with a `#commit()` right after (the test case does this). To fix this we now defer walking up the tree until the batch is actually processed. That way we set + unset the markers on the branches synchronously so there's no chance of another batch interfering.	1 day ago

Author

SHA1

Message

Date

Simon H

ce89035ecb

fix: prevent effect tree of batches from interfering with each other (#18508 )

While working on another Svelte feature I noticed a bug that boils down
to batches interfering with each other through the effect tree: If batch
A schedules an effect, it is walked up to the root (possibly). Now if in
the meantime batch B also wants to schedule effects, it can have
unintended consequences.

Normally this does not happen, since it's extremely hard to run into
this situation. There's basically two cases: Either an unfortunate
timing of microtasks, or during flushing effects are scheduling new
effects which messes with a `#commit()` right after (the test case does
this).

To fix this we now defer walking up the tree until the batch is actually
processed. That way we set + unset the markers on the branches
synchronously so there's no chance of another batch interfering.

1 Commits (each-fallback-scope)