BUG | `useElementVisibility` | Possible issue with `once` watcher inside of callback · vueuse/vueuse#4704

(1 comment) (1 reaction) (0 assignees)TypeScript (2,269 forks)batch import

good first issuehas pr

Repository metrics

Stars: (18,007 stars)
PR merge metrics: (Avg merge 34d 8h) (18 merged PRs in 30d)

Description

Describe the bug

I was looking at the source code for this composable and noticed that the watchOnce call is happening inside of the intersection callback.

https://github.com/vueuse/vueuse/blob/44b402ef2c236c6418fab9526443db0ba9f8b8b4/packages/core/useElementVisibility/index.ts#L60-L64

Was this intentional? Wouldn't this create a new watcher on each update, kind of separate to the initial effect scope? I would have guessed that this hook would have to be outside of the useIntersectionObserver call.

Reproduction

n/a

System Info

n/a

Used Package Manager

npm

Validations

Follow our Code of Conduct
Read the Contributing Guidelines.
Read the docs.
Check that there isn't already an issue that reports the same bug to avoid creating a duplicate.
Make sure this is a VueUse issue and not a framework-specific issue. For example, if it's a Vue SFC related bug, it should likely be reported to https://github.com/vuejs/core instead.
Check that this is a concrete bug. For Q&A open a GitHub Discussion.
The provided reproduction is a minimal reproducible example of the bug.

Contributor guide

Research direction: Examine the watchOnce call inside the IntersectionObserver callback in useElementVisibility to determine if it creates a new watcher each time and whether it should be moved outside the callback.
Tech stack: typescript
Domain: frontend
Issue type: Bug
Difficulty: 3
Estimated time: Half day
Activity status: Active
Clarity: Clear
Prerequisites: VueVueUse
Newbie friendliness: 40