In edge cases it may happen that set_attributes is re-run before the effect is executed. In that case the render effect which initiates this re-run will destroy the inner effect and it will never run. But because next and prev may have the same keys, the event would not get added again and it would get lost. We prevent this by using a root effect.
The added test case doesn't fail for some reason without this fix, but it does fail when you test it out manually, so I still added it.
Found through https://github.com/sveltejs/svelte/issues/10359#issuecomment-2101167524
* fix: make `$effect.active()` true when updating deriveds
* WIP
* this seems to work?
* prevent effects being created in unowned deriveds
* update test
* fix issue
---------
Co-authored-by: Dominic Gannaway <dg@domgan.com>
* fix: use snippet as parent element of snippets childrens in validator
* Update packages/svelte/src/compiler/phases/2-analyze/validation.js
* Update .changeset/wet-pears-remain.md
---------
Co-authored-by: Rich Harris <hello@rich-harris.dev>
* fix: use acceptExports to support partial hmr
* fix: add condition to only use acceptExports when it is available
* fix: update test snapshot
* fix: format
* Fixed: bind:scroll resets scroll state
* failing test
* bail if value is undefined
* changeset
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
Deriveds where under certain conditions not detected as dirty correctly. The reason is that a transitive check_dirtiness call could update the flag of a derived, even if the condition doesn't ulimately result to true. That's why the check for "is now dirty" needs to be moved out of the inner if block.
Fixes#11481
This may also fix a yet undetected overfiring bug in the "is unowned" case because the previous inner "is now dirty?" check didn't take unowned into account.
fixes#11483
We need to keep track of the component function similar to how we keep track of the component context, so that effects etc have the correct one associated
Ownership validation had a false positive when rendering a component as slotted content of another component. To fix this, #11401 did set the current component context to the context the snippet was declared in, not to the context it is rendered in. This was flawed because it means that component context was altered in a way that setContext/getContext failed because the parent chain was incorrect. This fixes that by introducing a separate global (dev time only) which tracks the component function the ownership needs.
fixes#11429
Instead of using types that declare whether or not a type is bindable directly as part of the property, we're introducing a new for-types-only field to `SvelteComponent`: `$$bindings`, which is typed as the keys of the properties that are bindable (string by default, i.e. everything's bindable; for backwards compat). language-tools can then produce code that assigns to this property which results in an error we can display if the binding is invalid
closes#11356
* fix: handle reassignment of `$$props` and `$$restProps`
Some libraries assign to properties of `$$props` and `$$restProps`. These were previously resulting in an error but are now handled properly
https://github.com/sveltejs/svelte/issues/10359#issuecomment-2080067464
* $$props is coarse grained on updates, so we can simplify this
* fix
* fix comment
When spreading attributes, the setters of the element are checked. If they contain the key in question, it's set via that setter. For certain setters on certain elements this didn't work because the element prototype was not HTMLElement, rather a descendant of that (for example HTMLDivElement), which meant that only the setters of the descendant, not the superclass were taken into account. This fixes that by walking up the prototype chain until we find the Element prototype.
fixes#11179
* feat: leave view transition pseudo selectors untouched
view transition pseude selectors are global-like, i.e. they shouldn't be scoped or treated as unused.
In the process of adding support for this, is_root and is_host were consolidated into is_global_like because their usage locations didn't need any differentiation between them (same for the new view transition treatment)
closes#9127
* regenerate types
previously a reaction could be marked as DIRTY and subsequently as MAYBE_DIRTY before running, resulting in false negatives. Ensure that DIRTY flag can never be lowered to MAYBE_DIRTY
fixes#11363
at rules are now left alone and you can have nested css in them which is scoped correctly. This just adds a test so we don't regress in the future
closes#9267
Provides a migration function, exported as `migrate` from `svelte/compiler`, which tries its best to automatically migrate towards runes, render tags (instead of slots) and event attributes (instead of event handlers)
The preview REPL was updated with a migrate button so people can try it out in the playground.
closes#9239
* feat: only inject push/init/pop when necessary - closes#11297
* regenerate
* differentiate between safe/unsafe
* only inject $$props when necessary
* more
* fix
* simplify
* handle store subscriptions
* chore: directly export function in non-HMR mode
* remove some more noise
* update snapshots
* Update sites/svelte-5-preview/src/lib/workers/compiler/index.js
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
---------
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* start reorganising messages
* tidy up
* more
* more
* more
* alphabetise
* consolidate
* more
* more
* more
* more
* more
* more
* alphabetise
* more
* this is no longer needed
* no longer necessary
* more
* more
* fix
* regenerate messages
* more
* more
* tighten up rune validation
* more
* fix
* more
* tweak a11y messages
* add server errors
* overhaul runtime errors
* regenerate messages
* unused
* lint
* more
* more
* Update packages/svelte/messages/compile-errors/script.md
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* Update packages/svelte/messages/client-warnings/warnings.md
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* fix
---------
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* fix: mark `accessors` and `immutable` as deprecated
* add warnings for deprecated <svelte:options> attributes
* disable accessors in runes mode
* update tests
* tidy up
* the hell?
* regenerate types
* if I would get a dollar for every windows bug I fix I would be a millionaire by now
* return instance _and_ props in runes mode, move flushSync into shared code, don't set accessors in runes mode
* goddammit
* note breaking change
* fix
* regenerate messages
* Revert "return instance _and_ props in runes mode, move flushSync into shared code, don't set accessors in runes mode"
This reverts commit a47827e57d.
* pass instance to tests
---------
Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
This is a typings PR and the companion PR to sveltejs/language-tools#2336
It introduces two new types:
- Binding: Marks a property as being bound (i.e. you must do bind:x)
- Bindable: Marks a property as being able to be bound (i.e. you can do bind:x)
Language tools then uses this generate code accordingly which then generates type errors.
All the other type gymnastics are there to ensure that you don't interact with these bindable types when using mount or hydrate or ComponentProps<MyComponent>, i.e. these two types should be mostly opaque for day-to-day users.
For backwards-compatibility, all properties are automatically wrapped with Bindable, which means existing type definition files will continue to work from a types perspective. Language tools opts into strict bindability by providing its own constructor definition for all generated classes in runes mode which omits the "wrap everything with bindable" behavior.
* breaking: disallow binding to component exports in runes mode
Svelte 4 allowed you to have `export const foo = ..` in component A and then do `<A bind:foo />`. This is confusing because it's not clear whether the binding is for a property or an export, and we have to sanitize rest props from the export bindings.
This PR therefore introduces a breaking change in runes mode: You cannot bind to these exports anymore. Instead use `<A bind:this={a} />` and then do `a.foo` - makes things easier to reason about.
* Update sites/svelte-5-preview/src/routes/docs/content/03-appendix/02-breaking-changes.md
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* tweak messages
* fix tests
* use component.name
* oops
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* fix: run event attributes after binding event listeners
By running the event listener logic inside an effect on the first run we guarantee that they're attached after binding listeners. Fixes#11138.
* give arrow functions stable id, better code gen
* optimise normal function expressions too (rare but valid!)
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* fix: fall back to component namespace when not statically determinable
In #10006 we added more elaborate mechanisms to determine which namespace a given element is in. For `<svelte:element>` we added a "can't know at compile time" case and introduced a limited heuristic into the runtime.
This doesn't work for a few reasons:
- we're checking the parent's namespace to determine the current namespace, but the element itself could be the one that _changes_ the namespace
- as mentioned in the previous comment already, on the first render we can't do any parent analysis
- it does not take into account the static component namespace
The last point is the crucial one: In Svelte 4, we're falling back to the component namespace if we can't know statically - e.g. if someone added `<svelte:options namespace="svg">` then `<svelte:element>` should fall back to that namespace instead.
We were not doing that up until now, which introduced a regression. Fixing this also means getting rid of the (flawed) "can't know statically" heuristic.
Fixes#10858, though for a complete solution we likely need some way to tell `<svelte:element>` the namespace at runtime through a special attribute. Maybe we can use `xmlns` for that like we do in the static case
* support dynamic svelte:element namespace through xmlns attribute
* fix
* feat: allow $inspect reactivity map, set, date
* feat: inspect map without adding new data source
* feat: add inspect
* feat: define inspect on dev mode only
* fix: lint error
Ownership was not widened when assigning a sub state to a different top level state. The set of owners for the state was zero because the owner was on the original parent, but that one was reset to null because it's now the top level of a different state. That meant that there was no owner but also no parent to check for the owner, which is an invalid combination resulting in a nullpointer (and also potentially false positive warnings in other situations).
fixes#11204
* breaking: warn/error on old syntax in runes mode
- warn on slots and event handlers in runes mode
- error on `<slot>` + `{@render ...}` tag usage in same component
closes#9416
* render tag + slot could occur in legacy mode as well, error there, too
* rename metadata.o to metadata.owners, tweak check_ownership implementation
* track parent relationships
* update
* changeset
* adjust test to reflect new semantics
* prevent component using bind: with object it does not own
* failing test
* fix#11060
* add explanatory comment
* don't accidentally narrow global ownership, fix has_owner method
* widen ownership if assigning different state proxies to one another
* don't set owners to null when parent exists
* fix
* only recurse into POJOs
* handle cycles on context
---------
Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
Co-authored-by: Dominic Gannaway <dg@domgan.com>
- don't call fallback values eagerly, only when it's actually needed. Avoids potential unwanted side effects
- use derived_safe_equals to memoize results of destructured snippet/each context values with default values to ensure they're only recalculated when their dependencies change. Avoids unstable default values getting called multiple times yielding different results. Use derived_safe_equals to ensure new values are always set, even when mutated. fixes#11143
* added raw elements set
* added test
* added changeset
* moved raw text elements to constands and made array
* moved to correct constants
* fix test
* fix constants formatting
* feat: hot module reloading support for Svelte 5
* fix lockfile
* tweaks
* types
* lint
* lint
* tweaks
* add hmr flag
* tweak
* tweaks
* move HMR logic into its own module
* simplify
* tidy up types
* fix test
* lint
* need some indirection here or references break
* prevent transitions during HMR update
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
* fix: loosen proxy signal creation heuristics
* tighten up test
* update comment
* no need to create a source outside an effect here, because it can't result in a reference
* preserve reference to props.$$events
---------
Co-authored-by: Rich Harris <rich.harris@vercel.com>
Simon H
Paolo Ricciuti
Dominic Gannaway
Fabio Rotondo
Rich Harris
Dominik G
Vladislav Logvin
Hunter Johnston
Luke Warlow
Jeremiasz Major
Caique Torres
Craig Jennings
Vaibhav Rai
Tan Li Hau
Daniel