* docs: make legacy.componentApi more visible
People didn't know that this exists, so we should make it more visible through having it be part of the error message, and calling it out in the docs with more details
* clarify
* flesh out message, put error behind a function
* make it work with HMR
* fix
* fix
* this makes it work. i don't fully understand why
* changeset
* changeset
* Delete .changeset/twelve-foxes-press.md
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
The current type narrows the binding type to `""` by default, which means "no bindings on this component". While this is the common case, it makes it very cumbersome to use the `Component` type because legacy components are of type `string` and as soon as you have bindings, the type is something like `"foo" | "bar"` which _also_ is not assignable to `""` which is semantically wrong, because you should be able to assign a component that can have bindings to a type that accepts none.
The pragmatic solution is to change the binding type to allow `string`, which means someone theoretically could use bindings with a component that doesn't have bindings:
```svelte
<script>
let component: Component<{ prop: boolean }> = IAcceptNoBindings;
</script>
<!-- allowed but should be a type error -->
<svelte:component this={component} bind:prop={foo} />
```
But this is a) rare anyway and b) can be caught at runtime
This came up in comments of #11775
* fix: append start/end info to more tags
We should add them everywhere we can
Related https://github.com/sveltejs/language-tools/pull/2385
* changeset
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
Also remove create_block function in favor of calling visit which in turn calls the fragment visitor, to ensure scope is updated correctly
Fixes#11450
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
Both `<svelte:element this="div">` and `<svelte:element this={"div"}>` were backported as `tag: "div"` for the old AST. That's wrong because the latter should result in `tag: { type: 'Literal', .. }`. Fixing this makes all the tests in prettier-plugin-svelte pass with Svelte 5.
Also cleaned up a bit of code in the parser.
* fix: populate `this.#sources` when constructing reactive map
* populate sources in first #read_all
* use increment helper
* use numbers instead of symbols
* make forEach work
* feat: bind `activeElement` and `pointerLockElement` in `<svelte:document>`
* add test, use focusin/focusout rather than focus/blur
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* fix: silence `state_referenced_locally` when state is exported
* chore: add changesets
* chore: use `some`
* fix
* better
* we don't need a whole new test for this
* Update .changeset/few-zoos-own.md
* prettier
* tidy up the test a bit since we're in here
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
Co-authored-by: Rich Harris <hello@rich-harris.dev>
* fix: keep default values of props a proxy after reassignment
* fix: make this work for non bindable props too
* chore: more comprehensive test
* chore: cast away
* chore: better variable name and check
* chore: fix lint
I noticed that we spend a lot of time dealing with a recursive function when propagating events. Let's avoid that overhead and move back to a much faster while loop. We can also stack the errors and throw them at the end.
Closes#11727.
This PR aims to tackle issues around our reactive Map/Set implementations. Notably:
- We now store the values on the backing Map/Set, allowing for much better introspection in console/dev tools
- We no longer store the values inside the source signals, instead we use Symbols and booleans only as markers
There's one limitation around `.has(x)` when `x` is not in the Map/Set yet - it's not fine-grained. Making it so could create too much memory pressure when e.g. iterating a big list of items with few of them being in the set (`has` returns `false` most of the time).
When a proxy is reassigned, we call `$.proxy` again. There are cases where there's a component context set but the reassignment actually happens for variable that is ownerless within shared state or somewhere else. In that case we get false positives right now. The inverse is also true where reassigning can delete owners (because no component context exists) and result in false negatives. The fix is to pass the previous value in to copy over the owners from it.
Fixes#11525
Fixes#11817.
It turns out that we weren't fully handling the disconnection of derived signals from the reactivity graph – resulting in cases where they could leak memory because they were not being removed from their dependency reactions array. However, removing ourselves from this array meant that any future changes might mean we need to reconnect the derived to the graph again – so we have to do some additional bookkeeping to make this work. Thankfully, we already have versioning because of unowned deriveds, we can use the versions to understand if the owned derived signal is dirty after being connected to the reactivity graph again – something we couldn't do in early permutations of the signal architecture – and likely why we hadn't addressed this in the same sense.
If a property is mutated, the assumption is that it is deeply reactive. In those cases, the fallback value should be proxified so that it also is deeply reactive.
fixes#11425
- the previous assumption was wrong: browser don't fire a scroll event initially when the scroll isn't smooth
- the previous logic wasn't using the "is scrolling now" logic which meant the render effect fired immediately after, causing smooth scrolling to start too late to be overridden
adjusted the comment and reused the scroll handler function to guard against the race condition
fixes#11623
In Svelte 3 and 4, components were classes under the hood, and the base class was `SvelteComponent`. This class was also used in language tools to properly type check the template code.
In Svelte 5, components are functions. To give people a way to extend them programmatically, it would be good to expose the actual shape of components. This is why this PR introduces a new `Component` type.
For backwards compatibility reasons, we can't just get rid of the old class-based types. We also need to ensure that language tools can work with both the new and old types: There are many libraries out there that provide `d.ts` files with type definitions written using the class types - these should not error.
That's why there's an accompagning language tools PR (https://github.com/sveltejs/language-tools/pull/2380) that's doing the heavy lifting: Instead of generating classes, it now generates a constant and an interfaces and uses Typescript's declaration merging feature to provide both so we can declare a component export as being both a class and a function. That ensures that people can still instantiate them with `new` (which they can do if they use the `legacy.componentApi` compiler option), and it also ensure we don't need to adjust any other code generation mechanisms in language tools yet - from a language tools perspective, classes are still the norm. But through exposing the default export as being _also_ callable as a function we can in a future Svelte version, where classes/the Svelte 4 syntax are removed completely, seamlessly switch over to using functions in the code generation, too, and the `d.ts` files generated up until that point will support it because of the dual shape. This way we have both backwards and forwards compatibility.
We didn't delegate the input event back when we were also delegating `on:x` events, because it messes up the event/bindings/actions order. Since we're only doing that for `onx` event attributes now that reason is obsolete and we can start delegating it.
The value attribute on select elements does nothing - it does not influence the initial value (in SSR that's the job of the `selected` attribute on an option element), updating it does not influence the current value either. Instead of rendering it out and then removing it on hydration (which is costly because the mutation causes work) we just don't render it in SSR.
No test/changeset because no change in behavior.
* breaking: disallow string literal values in `<svelte:element this="...">`
* note breaking change
* Update sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
Co-authored-by: Jeremiasz Major <jrh.mjr@gmail.com>
* prettier
* make invalid `<svelte:element this>` a warning instead of an error (#11641)
* make it a warning instead of an error
* format
---------
Co-authored-by: Jeremiasz Major <jrh.mjr@gmail.com>
In the case of an invalid child element, we already get information about the parent and the child, but in other cases where a mismatch could occur you're pretty much on your own.
This adds a bit more context to hydration_mismatch warnings — 'The error occurred near ...'
* feat: add rootDir option and set __svelte_meta.file like in svelte4
* Update packages/svelte/src/compiler/validate-options.js
* update tests
* centralise logic
* fix
* note to self
* Apply suggestions from code review
* lint
* one dollar towards the windows backslash bugfix foundation please
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
* Revert "chore: ensure we use event system code paths throughout (#11640)"
This reverts commit c00d8245ee.
* Update packages/svelte/src/internal/client/dom/elements/attributes.js
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
* feat: add $state.is rune
* fix type
* tweak docs
* may as well update the test case to match the docs
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Co-authored-by: Rich Harris <rich.harris@vercel.com>
* chore: improve SSR invalid element error message
* move push_element and pop_element into new dev.js file
* pass location info, remove unnecessary if (DEV) block
* use full filename, basename is not very helpful. also, current_component is guaranteed to not be null
* current_element is guaranteed to not be null in pop_element
* tweaks
* remove message prefix - redundant when filenames are included
* add line/column
* make message more concise
* reduce indirection
* only print message once
* update test
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
Instead of hacking an ignores array onto each node (and possibly degrading perf a bit because the object shape is mutated) we keep track of ignores in a stack. The new approach also avoids the indirection the old one had to do because the new approach looks upwards (checking if parent is a fragment) instead of iterating the children (checking for comments in them).
As a bonus unknown code warnings are now in order (line-column-wise) with the other warnings. Also fixes#11482 because text nodes of all shapes are ok
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