svelte

Patch Changes

• don't create async deriveds for a component destroyed while waiting for its top-level await

• prevent untracked derived reads from retaining disconnected dependencies

• error if {:else} is followed by another {:else} or {:else if ...}

• avoid tracking SvelteURLSearchParams during URL updates

• restore hydration state when custom element attribute updates throw

• attach event handlers that are assigned after a top-level await in production

• flush anything pending before invoking flushSync callback function

• preserve location information for await wrappers

• keep a reactive assignment with no dependencies when migrate cannot turn it into a declaration

• don't hang migrate on a declaration that shares a line with its script tag

• prevent duplicate subscriptions when reconnecting deriveds

• recover when an unexpected node replaces a nested boundary comment during hydration

• print {#await} blocks that only have a pending branch

• don't warn about a redundant link role on <area> elements without an href

• don't throw state_unsafe_mutation when the focused element is removed while bind:activeElement is used

• don't overwrite an unchanged spread value, preserving incomplete number input

• read batch-local array on each-block commit

• error at compile time when a declaration in a snippet redeclares one of its parameters

• error when using let: directives on a component with a children snippet

• ignore stale boundary reset callbacks

• handle deferred transitions aborted before initialization

• prevent hydration mismatch recovery from being intercepted by error boundaries

• preserve dynamic element connections during hydration

Patch Changes

• cancel deferred event listeners during cleanup

• preserve global CSS in components without scopable elements

• reduce SSR render result garbage collection

• resolve the fallback of an each block in the enclosing scope

• speed up parser interactions with Acorn or avoid them where possible

• prevent effect tree of batches from interfering with each other

• serialize input default values during server rendering

• remove WAS_MARKED flag in favor of Set

• throw set_context_after_init when setContext is called after an await during SSR

• make Object.hasOwn reactive for state proxy ownership changes

• keep $state.eager when used as a variable initializer

• avoid regex matching in parser where possible

• in non-async mode, only push variable to current_sources when active_reaction is updating

• recognise aria-braillelabel and aria-brailleroledescription as known ARIA attributes

Minor Changes

• export RenderOutput, SyncRenderOutput, Csp and Sha256Source from svelte/server

• add has function to createContext

• support defaultValue on <select>

• add getOrInsert/getOrInsertComputed to SvelteMap

Patch Changes

• block template store subscriptions on the promise that assigns the store

• route $derived teardown errors through invoke_error_boundary

• track SvelteDate snapshots in reactions

• remove <svelte:head> anchors on unmount

• warn on undeclared shorthand event handlers on <svelte:window>, <svelte:document> and <svelte:body>

• reuse the cached value in the <option>/<select> value guard

• prevent malformed AST output for <select> with static value attribute

• apply ownership mutation ignores to binding assignments

• prevent onoutroend from firing twice when compilerOptions.hmr is true

• preserve whitespace after inline elements when printing

• fold SSR block-open markers into the branch's first push

• run onDestroy callbacks when a server render throws

• report derived_invalid_export for export let x = $derived(...) in runes mode

• never apply class hash to elements inside <svelte:head>

• keep defaultChecked on hydrated radio inputs with spread attributes

• accept onfocusin/onfocusout in a11y_mouse_events_have_key_events

• O(n²)→O(n) Map lookups for legacy $: reactive statement ordering

• distinct memoizer on style/class directives

• measure nested transitions before applying their starting styles

• don't turn component instances stored in $state into state proxies

• emit $.only_child for elements with a single child

• omit bind:focused from SSR output (it has no HTML attribute)

• more robust rendering of Svelte custom element slots

• optimize simple object destructuring in @const tags

• properly apply static textarea value attribute during CSR

• end a restored reaction context at the end of its synchronous segment

• keep the dependencies of a reaction that throws, so deriveds it read are neither leaked nor stuck in their error

• don't resurrect outroing elements when an ancestor block is paused and resumed

• use $.comment() for single-comment templates

• store setters cache as Set instead of Array

• transform derived assignments and select function bindings correctly during server-side rendering

• keep boolean attributes with an empty string value when rendering attribute objects on the server

• sync SvelteURL port signal when the protocol setter clears the port

• block declaration tags and {@const} on async values read inside closures

• avoid css tree-shaking for exported Snippet

• treat <img loading> as a static element again

• prevent selectedcontent mutation from changing the selected option

• avoid NaN keyframe values in slide transition for elements without a layout box

• preserve line feed character references in attribute values

• decode uppercase-X hex numeric character references (&#X...;)

• scope SSR boundary failed snippets to their boundary

Patch Changes

• preserve CSS escape sequences when printing selectors

• parse :nth-child(2n of.foo) where of is not followed by whitespace

• transform expressions inside labeled statements during server compilation

• apply CSS custom properties with falsy values on components

• correctly print {#await ... catch x} et al

• ignore comments of Program node during migration script

• reliably resolve append_style to its correct root

• clean up removed capture event handlers from spread attributes

• don't corrupt renderer type during SSR's legacy bind: retry loop

• treat concise arrow function bodies as implicit returns when calculating blockers

• give effect teardowns the value from before the first write in a flush

• avoid double-calling a derived reference when destructuring $derived of another $derived during server-side rendering

• preserve namespaces in CSS type selectors

• increment private state fields through a non-this receiver

• release last_propagated_event after event propagation settles so it no longer retains the last event's target subtree

• allow custom elements to receive async values as props

• strip comments from inline style values in linear time

• prevent declaration comments from breaking server derived references

• make async blocker analysis scale linearly with the number of top-level references

• preserve short-circuiting for logical assignments to private state fields

Patch Changes

• skip controlled each fast path while another batch is pending

• better whitespace handling inside printer

• don't duplicate comments in attributes

• preserve CSS comments in the AST printer