@ -43,7 +43,7 @@ The maintainers meet on the final Saturday of each month. While these meetings a
### Prioritization
We do our best to review PRs and RFCs as they are sent, but it is difficult to keep up. We welcome help in reviewing PRs, RFCs, and issues. If an item aligns with the current priority on our [roadmap](https://svelte.dev/roadmap), it is more likely to be reviewed quickly. PRs to the most important and active ones repositories get reviewed more quickly while PRs to smaller inactive repos may sit for a bit before we periodically come by and review the pending PRs in a batch.
We do our best to review PRs and RFCs as they are sent, but it is difficult to keep up. We welcome help in reviewing PRs, RFCs, and issues. If an item aligns with the current priority on our [roadmap](https://svelte.dev/roadmap), it is more likely to be reviewed quickly. PRs to the most important and active repositories get reviewed more quickly while PRs to smaller inactive repos may sit for a bit before we periodically come by and review the pending PRs in a batch.
@ -167,6 +167,8 @@ To take a static snapshot of a deeply reactive `$state` proxy, use `$state.snaps
This is handy when you want to pass some state to an external library or API that doesn't expect a proxy, such as `structuredClone`.
If a value has a `toJSON` method, the snapshot will clone the value returned from `toJSON` instead of the original object.
## `$state.eager`
When state changes, it may not be reflected in the UI immediately if it is used by an `await` expression, because [updates are synchronized](await-expressions#Synchronized-updates).
@ -241,7 +241,7 @@ When the value of an `<option>` matches its text content, the attribute can be o
</select>
```
You can give the `<select>` a default value by adding a `selected` attribute to the`<option>` (or options, in the case of `<select multiple>`) that should be initially selected. If the `<select>` is part of a form, it will revert to that selection when the form is reset. Note that for the initial render the value of the binding takes precedence if it's not `undefined`.
You can give the `<select>` a default value by adding a `selected` attribute to the`<option>` (or options, in the case of `<select multiple>`) that should be initially selected. If the `<select>` is part of a form, it will revert to that selection when the form is reset. Note that for the initial render the value of the binding takes precedence if it's not `undefined`.
Similarly, to pass primitive values through context, use functions as described in [Passing state into functions]($state#Passing-state-into-functions).
## Component testing
When writing [component tests](testing#Unit-and-component-tests-with-Vitest-Component-testing), it can be useful to create a wrapper component that sets the context in order to check the behaviour of a component that uses it. As of version 5.49, you can do this sort of thing:
While the process is very straightforward, it is also low level and somewhat brittle, as the precise structure of your component may change frequently. Tools like [@testing-library/svelte](https://testing-library.com/docs/svelte-testing-library/intro/) can help streamline your tests. The above test could be rewritten like this:
```js
// @errors: 2339
/// file: component.test.js
import { render, screen } from '@testing-library/svelte';
import userEvent from '@testing-library/user-event';
@ -270,9 +300,9 @@ You can create stories for component variations and test interactions with the [
@ -134,6 +134,14 @@ When logging a [proxy](https://developer.mozilla.org/en-US/docs/Web/JavaScript/R
The easiest way to log a value as it changes over time is to use the [`$inspect`](/docs/svelte/$inspect) rune. Alternatively, to log things on a one-off basis (for example, inside an event handler) you can use [`$state.snapshot`](/docs/svelte/$state#$state.snapshot) to take a snapshot of the current value.
### derived_inert
```
Reading a derived belonging to a now-destroyed effect may result in stale values
```
A `$derived` value created inside an effect will stop updating when the effect is destroyed. You should create the `$derived` outside the effect, or inside an `$effect.root`.
- fix: promise-ify `{#await await ...}` expressions on the server and correctly hydrate them on the client ([#18243](https://github.com/sveltejs/svelte/pull/18243))
- fix: deduplicate dependencies that are added outside the init/update cycle ([#18243](https://github.com/sveltejs/svelte/pull/18243))
- fix: inline primitive constants in attribute values during SSR ([#18232](https://github.com/sveltejs/svelte/pull/18232))
## 5.55.8
### Patch Changes
- fix(print): handle `svelte:body` and fix keyframe percentage double-printing ([#18234](https://github.com/sveltejs/svelte/pull/18234))
- fix: execute uninitialized derived even if it's destroyed ([#18228](https://github.com/sveltejs/svelte/pull/18228))
- fix: use named symbols everywhere ([#18238](https://github.com/sveltejs/svelte/pull/18238))
- fix: don't run teardown effects when deriveds are unfreezed ([#18227](https://github.com/sveltejs/svelte/pull/18227))
- fix: unset context synchronously in `run` ([#18236](https://github.com/sveltejs/svelte/pull/18236))
## 5.55.7
### Patch Changes
- fix: prevent XSS on `hydratable` from user contents ([`a16ebc67bbcf8f708360195687e1b2719463e1a4`](https://github.com/sveltejs/svelte/commit/a16ebc67bbcf8f708360195687e1b2719463e1a4))
- fix: disallow empty attribute names during SSR ([`547853e2406a2147ad7fb5ffeba95b01bd9642da`](https://github.com/sveltejs/svelte/commit/547853e2406a2147ad7fb5ffeba95b01bd9642da))
@ -120,6 +120,12 @@ When logging a [proxy](https://developer.mozilla.org/en-US/docs/Web/JavaScript/R
The easiest way to log a value as it changes over time is to use the [`$inspect`](/docs/svelte/$inspect) rune. Alternatively, to log things on a one-off basis (for example, inside an event handler) you can use [`$state.snapshot`](/docs/svelte/$state#$state.snapshot) to take a snapshot of the current value.
## derived_inert
> Reading a derived belonging to a now-destroyed effect may result in stale values
A `$derived` value created inside an effect will stop updating when the effect is destroyed. You should create the `$derived` outside the effect, or inside an `$effect.root`.
## event_handler_invalid
> %handler% should be a function. Did you mean to %suggestion%?
console.warn(`%c[svelte] derived_inert\n%cReading a derived belonging to a now-destroyed effect may result in stale values\nhttps://svelte.dev/e/derived_inert`,bold,normal);
Rich Harris
4 weeks ago