Show double evaluation #2411
Open
Show double evaluation #2411
+231
−62
Conversation
This file contains 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
The `<Show>` component evaluates its `when` condition more often than necessary, in particular it is immediately evaluated twice if the condition is true, children is specified as a function, and keyed is not specified. solidjs#2406
Adds another memo directly on `when` in `<Show>`. solidjs#2406
This removes a bug where the `when` condition of a `<Match>` was evaluated twice immediately after creation, when the condition was true, children was a function and keyed was not specified. It also removes any unnecessary conditions evaluations by creating a memo on every `when` in a `Switch`.
For example, if a `<Switch>` has two `<Match>`es with `when={a()}` and `when={b()}` respectively, then:
- `b()` is never called if `a()` is truthy (which was true also before this change),
- `a()` is never called when `b()` changes (which is new).
solidjs#2406
🦋 Changeset detectedLatest commit: 2174599 The changes in this PR will be included in the next version bump. This PR includes changesets to release 2 packages
Not sure what this means? Click here to learn what changesets are. Click here if you're a maintainer who wants to add another changeset to this PR |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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Outdated suggestions cannot be applied.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.
Summary
This change removes unnecessary evaluations of the
whenconditions in the<Show>and<Match>components. Both these components used to evaluate the condition twice immediately after creation if the condition was true, children was specified as a function and keyed was not specified.This was especially problematic when the condition produced
JSX.Elementwhich was then displayed by the children function, as two copies of the elements were instantiated.This change also removes unnecessary evaluations of
<Match>conditions in a sutiation where the condition did not change, but only a later<Match>'s condition changed.How did you test this change?
Added unit tests demonstrating the described problems, and made
pnpm testpass.fixes #2406