Update guidance on when updater functions are needed for useState to account for transitions#8456
Open
captbaritone wants to merge 1 commit into
Open
Conversation
The existing DeepDive overstated the guarantee that state is always up-to-date before the next user action. This is not true when the state variable has been updated inside a Transition elsewhere in the app, or when multiple updates happen in the same event handler. Restructure to present both cases together and contrast the two approaches (reading the state variable vs. using an updater).
Size changesDetails📦 Next.js Bundle Analysis for react-devThis analysis was generated by the Next.js Bundle Analysis action. 🤖 This PR introduced no changes to the JavaScript bundle! 🙌 |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The existing deep dive on when to use updater functions vs the state variable from render predates the introduction of transitions and makes strong claims which are no-longer fully true. Specifically (emphasis mine):
This is not "always" true, since the state update in the intentional user action may have been wrapped in a
startTransition.There is some risk since the state may be updating as part of transition.
This PR attempts to restructure the guidance to account for this added complexity while keeping the mental overhead for users as minimal as possible while staying honest.