CHANGELOG.md

svelte

4.2.5

Patch Changes

• fix: ignore expressions in top level script/style tag attributes (#9498)

4.2.4

Patch Changes

• fix: handle closing tags inside attribute values (#9486)

4.2.3

Patch Changes

• fix: improve a11y-click-events-have-key-events message (#9358)

• fix: more robust hydration of html tag (#9184)

4.2.2

Patch Changes

• fix: support camelCase properties on custom elements (#9328)

• fix: add missing plaintext-only value to contenteditable type (#9242)

• chore: upgrade magic-string to 0.30.4 (#9292)

• fix: ignore trailing comments when comparing nodes (#9197)

4.2.1

Patch Changes

• fix: update style directive when style attribute is present and is updated via an object prop (#9187)

• fix: css sourcemap generation with unicode filenames (#9120)

• fix: do not add module declared variables as dependencies (#9122)

• fix: handle svelte:element with dynamic this and spread attributes (#9112)

• fix: silence false positive reactive component warning (#9094)

• fix: head duplication when binding is present (#9124)

• fix: take custom attribute name into account when reflecting property (#9140)

• fix: add indeterminate to the list of HTMLAttributes (#9180)

• fix: recognize option value on spread attribute (#9125)

4.2.0

Minor Changes

• feat: move svelteHTML from language-tools into core to load the correct svelte/element types (#9070)

4.1.2

Patch Changes

• fix: allow child element with slot attribute within svelte:element (#9038)

• fix: Add data-* to svg attributes (#9036)

4.1.1

Patch Changes

• fix: svelte:component spread props change not picked up (#9006)

4.1.0

Minor Changes

• feat: add ability to extend custom element class (#8991)

Patch Changes

• fix: ensure svelte:component evaluates props once (#8946)

• fix: remove let:variable slot bindings from select binding dependencies (#8969)

• fix: handle destructured primitive literals (#8871)

• perf: optimize imports that are not mutated or reassigned (#8948)

• fix: don't add accessor twice (#8996)

4.0.5

Patch Changes

• fix: generate type definition with nullable types (#8924)

4.0.4

Patch Changes

• fix: claim svg tags in raw mustache tags correctly (#8910)

• fix: repair invalid raw html content during hydration (#8912)

4.0.3

Patch Changes

• fix: handle falsy srcset values (#8901)

4.0.2

Patch Changes

• fix: reflect all custom element prop updates back to attribute (#8898)

• fix: shrink custom element baseline a bit (#8858)

• fix: use non-destructive hydration for all @html tags (#8880)

• fix: align disclose-version exports specification (#8874)

• fix: check srcset when hydrating to prevent needless requests (#8868)

4.0.1

Patch Changes

• fix: ensure identifiers in destructuring contexts don't clash with existing ones (#8840)

• fix: ensure createEventDispatcher and ActionReturn work with types from generic function parameters (#8872)

• fix: apply transition to <svelte:element> with local transition (#8865)

• fix: relax a11y "no redundant role" rule for li, ul, ol (#8867)

• fix: remove tsconfig.json from published package (#8859)

4.0.0

Major Changes

• breaking: Minimum supported Node version is now Node 16 (#8566)

• breaking: Minimum supported webpack version is now webpack 5 (#8515)

• breaking: Bundlers must specify the browser condition when building a frontend bundle for the browser (#8516)

• breaking: Minimum supported vite-plugin-svelte version is now 2.4.1. SvelteKit users can upgrade to 1.20.0 or newer to ensure a compatible version (#8516)

• breaking: Minimum supported rollup-plugin-svelte version is now 7.1.5 (198dbcf)

• breaking: Minimum supported svelte-loader is now 3.1.8 (198dbcf)

• breaking: Minimum supported TypeScript version is now TypeScript 5 (it will likely work with lower versions, but we make no guarantees about that) (#8488)

• breaking: Remove svelte/register hook, CJS runtime version and CJS compiler output (#8613)

• breaking: Stricter types for createEventDispatcher (see PR for migration instructions) (#7224)

• breaking: Stricter types for Action and ActionReturn (see PR for migration instructions) (#7442)

• breaking: Stricter types for onMount - now throws a type error when returning a function asynchronously to catch potential mistakes around callback functions (see PR for migration instructions) (#8136)

• breaking: Overhaul and drastically improve creating custom elements with Svelte (see PR for list of changes and migration instructions) (#8457)

• breaking: Deprecate SvelteComponentTyped in favor of SvelteComponent (#8512)

• breaking: Make transitions local by default to prevent confusion around page navigations (#6686)

• breaking: Error on falsy values instead of stores passed to derived (#7947)

• breaking: Custom store implementers now need to pass an update function additionally to the set function (#6750)

• breaking: Do not expose default slot bindings to named slots and vice versa (#6049)

• breaking: Change order in which preprocessors are applied (#8618)

• breaking: The runtime now makes use of classList.toggle(name, boolean) which does not work in very old browsers (#8629)

• breaking: apply inert to outroing elements (#8628)

• breaking: use CustomEvent constructor instead of deprecated createEvent method (#8775)

Minor Changes

• Add a way to modify attributes for script/style preprocessors (#8618)

• Improve hydration speed by adding data-svelte-h attribute to detect unchanged HTML elements (#7426)

• Add a11y no-noninteractive-element-interactions rule (#8391)

• Add a11y-no-static-element-interactionsrule (#8251)

• Allow #each to iterate over iterables like Set, Map etc (#7425)

• Improve duplicate key error for keyed each blocks (#8411)

• Warn about : in attributes and props to prevent ambiguity with Svelte directives (#6823)

• feat: add version info to window. You can opt out by setting discloseVersion to false in the compiler options (#8761)

• feat: smaller minified output for destructor chunks (#8763)

Patch Changes

• Bind null option and input values consistently (#8312)

• Allow $store to be used with changing values including nullish values (#7555)

• Initialize stylesheet with /* empty */ to enable setting CSP directive that also works in Safari (#7800)

• Treat slots as if they don't exist when using CSS adjacent and general sibling combinators (#8284)

• Fix transitions so that they don't require a style-src 'unsafe-inline' Content Security Policy (CSP) (#6662).

• Explicitly disallow var declarations extending the reactive statement scope (#6800)

• Improve error message when trying to use animate: directives on inline components (#8641)

• fix: export ComponentType from svelte entrypoint (#8578)

• fix: never use html optimization for mustache tags in hydration mode (#8744)

• fix: derived store types (#8578)

• Generate type declarations with dts-buddy (#8578)

• fix: ensure types are loaded with all TS settings (#8721)

• fix: account for preprocessor source maps when calculating meta info (#8778)

• chore: deindent cjs output for compiler (#8785)

• warn on boolean compilerOptions.css (#8710)

• fix: export correct SvelteComponent type (#8721)

4.0.0-next.3

Patch Changes

• feat: smaller minified output for destructor chunks (#8763)

• breaking: use CustomEvent constructor instead of deprecated createEvent method (#8775)

• fix: account for preprocessor source maps when calculating meta info (#8778)

• chore: deindent cjs output for compiler (#8785)

• feat: add version info to window. You can opt out by setting discloseVersion to false in the compiler options (#8761)

4.0.0-next.2

Patch Changes

• fix: never use html optimization for mustache tags in hydration mode (#8744)

• fix: ensure types are loaded with all TS settings (#8721)

• warn on boolean compilerOptions.css (#8710)

• fix: export correct SvelteComponent type (#8721)

4.0.0-next.1

Patch Changes

• fix: export ComponentType from svelte entrypoint (#8694)

• fix: derived store types (#8700)

• Generate type declarations with dts-buddy (#8702)

4.0.0-next.0

Major Changes

• breaking: Minimum supported Node version is now Node 16 (#8566)
• breaking: Minimum supported webpack version is now webpack 5 (#8515)
• breaking: Bundlers must specify the browser condition when building a frontend bundle for the browser (#8516)
• breaking: Minimum supported vite-plugin-svelte version is now 2.4.1. SvelteKit users can upgrade to 1.20.0 or newer to ensure a compatible version (#8516)
• breaking: Minimum supported rollup-plugin-svelte version is now 7.1.5 (198dbcf)
• breaking: Minimum supported svelte-loader is now 3.1.8 (198dbcf)
• breaking: Minimum supported TypeScript version is now TypeScript 5 (it will likely work with lower versions, but we make no guarantees about that) (#8488)
• breaking: Remove svelte/register hook, CJS runtime version and CJS compiler output (#8613)
• breaking: Stricter types for createEventDispatcher (see PR for migration instructions) (#7224)
• breaking: Stricter types for Action and ActionReturn (see PR for migration instructions) (#7442)
• breaking: Stricter types for onMount - now throws a type error when returning a function asynchronously to catch potential mistakes around callback functions (see PR for migration instructions) (#8136)
• breaking: Overhaul and drastically improve creating custom elements with Svelte (see PR for list of changes and migration instructions) (#8457)
• breaking: Deprecate SvelteComponentTyped in favor of SvelteComponent (#8512)
• breaking: Make transitions local by default to prevent confusion around page navigations (#6686)
• breaking: Error on falsy values instead of stores passed to derived (#7947)
• breaking: Custom store implementers now need to pass an update function additionally to the set function (#6750)
• breaking: Do not expose default slot bindings to named slots and vice versa (#6049)
• breaking: Change order in which preprocessors are applied (#8618)
• breaking: The runtime now makes use of classList.toggle(name, boolean) which does not work in very old browsers (#8629)
• breaking: apply inert to outroing elements (#8627)

Minor Changes

• Add a way to modify attributes for script/style preprocessors (#8618)
• Improve hydration speed by adding data-svelte-h attribute to detect unchanged HTML elements (#7426)
• Add a11y no-noninteractive-element-interactions rule (#8391)
• Add a11y-no-static-element-interactionsrule (#8251)
• Allow #each to iterate over iterables like Set, Map etc (#7425)
• Improve duplicate key error for keyed each blocks (#8411)
• Warn about : in attributes and props to prevent ambiguity with Svelte directives (#6823)

Patch Changes

• Bind null option and input values consistently (#8312)
• Allow $store to be used with changing values including nullish values (#7555)
• Initialize stylesheet with /* empty */ to enable setting CSP directive that also works in Safari (#7800)
• Treat slots as if they don't exist when using CSS adjacent and general sibling combinators (#8284)
• Fix transitions so that they don't require a style-src 'unsafe-inline' Content Security Policy (CSP) (#6662).
• Explicitly disallow var declarations extending the reactive statement scope (#6800)
• Improve error message when trying to use animate: directives on inline components (#8641)

3.59.2

• Fix escaping <textarea bind:value={...}> values in SSR

3.59.1

• Handle dynamic values in a11y-autocomplete-valid (#8567)

3.59.0

• Add ResizeObserver bindings contentRect/contentBoxSize/borderBoxSize/devicePixelContentBoxSize (#8022)
• Add devicePixelRatio binding for <svelte:window> (#8285)
• Add fullscreenElement and visibilityState bindings for <svelte:document> (#8507)
• Add a11y-autocomplete-valid warning (#8520)
• Fix handling of width/height attributes when spreading (#6752)
• Fix updating of interpolated style: directive when using spread (#8438)
• Remove style: directive property when value is undefined (#8462)
• Fix type of VERSION compiler export (#8498)
• Relax a11y-no-redundant-roles warning (#8536)
• Handle nested array rest destructuring (#8552, #8554)

3.58.0

• Add bind:innerText for contenteditable elements (#3311)
• Add support for CSS @container queries (#6969)
• Respect preserveComments in DOM output (#7182)
• Allow use of document for target in typings (#7554)
• Add a11y-interactive-supports-focus warning (#8392)
• Fix equality check when updating dynamic text (#5931)
• Relax a11y-no-noninteractive-element-to-interactive-role warning (#8402)
• Properly handle microdata attributes (#8413)
• Prevent name collision when using computed destructuring variables (#8417)
• Fix escaping <textarea value={...}> values in SSR (#8429)

3.57.0

• Add <svelte:document> (#3310)
• Add a11y no-noninteractive-element-to-interactive-role (#8167)
• Stop intro transition from triggering incorrectly (#6152, #6812)
• Support computed and literal properties when destructuring objects in the template (#6609)
• Give style: directive precedence over style= attribute (#7475)
• Select <option> with selected attribute when initial state is undefined (#8361)
• Prevent derived store callbacks after store is unsubscribed from (#8364)
• Account for bind:group members being spread across multiple control flow blocks (#8372)
• Revert buggy reactive statement optimization (#8374)
• Support CSS units in the fly and blur transitions (#7623)

3.56.0

• Add |stopImmediatePropagation event modifier (#5085)
• Add axis parameter to slide transition (#6182)
• Add readonly utility to convert writable store to readonly (#6518)
• Add readyState binding for media elements (#6666)
• Generate valid automatic component names when the filename contains only special characters (#7143)
• Add naturalWidth and naturalHeight bindings (#7771)
• Support <!-- svelte-ignore ... --> on components (#8082)
• Add a11y warnings:
  • aria-activedescendant-has-tabindex: checks that elements with aria-activedescendant have a tabindex (#8172)
  • role-supports-aria-props: checks that the (implicit) element role supports the given aria attributes (#8195)
• Add data-sveltekit-replacestate and data-sveltekit-keepfocus attribute typings (#8281)
• Compute node dimensions immediately before crossfading (#4111)
• Fix potential infinite invalidate loop with <svelte:component> (#4129)
• Ensure bind:offsetHeight updates initially (#4233)
• Don't set selected options if value is unbound or not passed (#5644)
• Validate component :global() selectors (#6272)
• Improve warnings:
  • Make noreferrer warning less zealous (#6289)
  • Omit a11y warnings on <video aria-hidden="true"> (#7874)
  • Omit a11y warnings on <svelte:element> (#7939)
  • Detect unused empty attribute CSS selectors (#8042)
  • Omit "no child content" warning on elements with aria-label (#8296)
• Check value equality for <input type="search"> and <input type="url"> (#7027)
• Do not select a disabled <option> by default when the initial bound value is undefined (#7041)
• Handle {@html} tags inside <template> tags (#7364)
• Ensure afterUpdate is not called after onDestroy (#7476)
• Improve handling of inert attribute (#7500)
• Reduce use of template literals in SSR output for better performance (#7539)
• Ensure <input> value persists when swapping elements with spread attributes in an {#each} block (#7578)
• Simplify generated code for reactive statements if dependencies are all static (#7942)
• Fix race condition on <svelte:element> with transitions (#7948)
• Allow assigning to a property of a const when destructuring (#7964)
• Match browser behavior for decoding malformed HTML entities (#8026)
• Ensure trusted-types CSP compatibility for Web Components (#8134)
• Optimise <svelte:element> output code for static tag and static attribute (#8161)
• Don't throw when calling unsubscribing from a store twice (#8186)
• Clear inputs when bind:group value is set to undefined (#8214)
• Fix handling of nested arrays with keyed {#each} containing a non-keyed {#each} (#8282)

3.55.1

• Fix draw transition with delay showing a dot at the beginning of the path (#6816)
• Fix infinity runtime call stack when propagating bindings (#7032)
• Fix static <svelte:element> optimization in production mode (#7937)
• Fix svelte-ignore comment breaking named slot (#8075)
• Revert change to prevent running init binding unnecessarily (#8103)
• Fix adding duplicate event listeners with <svelte:element on:event> (#8129)
• Improve detection of promises that are also functions (#8162)
• Avoid mutating spread component props during SSR (#8171)
• Add missing typing for global part attribute (#8181)
• Add missing submitter property to on:submit event type

3.55.0

• Add svelte/elements for HTML/Svelte typings (#7649)

3.54.0

• Pass options.direction argument to custom transition functions (#3918)
• Support fallback a11y WAI-ARIA roles (#8044)
• Prevent running init binding unnecessarily (#5689, #6298)
• Allow updating variables from @const declared function (#7843)
• Do not emit a11y-no-noninteractive-tabindex warning if element has a tabpanel (#8025)
• Fix escaping SSR'd values in style: directive (#8085)

3.53.1

• Fix exception in rel= attribute check with dynamic values (#7994)
• Do not emit deprecation warnings for css compiler options for now (#8009)
• Make compiler run in browser again (#8010)
• Upgrade tslib (#8013)

3.53.0

• Check whether parentNode exists before removing child (#6037)
• Upgrade various dependencies, notably css-tree to 2.2.1 (#7572, #7982)
• Extend css compiler option with 'external' | 'injected' | 'none' settings and deprecate old true | false values (#7914)

3.52.0

• Throw compile-time error when attempting to update const variable (#4895)
• Warn when using <a target="_blank"> without rel="noreferrer" (#6188)
• Support style:foo|important modifier (#7365)
• Fix hydration regression with {@html} and components in <svelte:head> (#7941)

3.51.0

• Add a11y warnings:
  • a11y-click-events-have-key-events: check if click event is accompanied by key events (#5073)
  • a11y-no-noninteractive-tabindex: check for tabindex on non-interactive elements (#6693)
• Warn when two-way binding to {...rest} object in {#each} block (#6860)
• Support --style-props on <svelte:component> (#7461)
• Supports nullish values for component event handlers (#7568)
• Supports SVG elements with <svelte:element>(#7613)
• Treat inert as boolean attribute (#7785)
• Support --style-props for SVG components (#7808)
• Fix false positive dev warnings about unset props when they are bound (#4457)
• Fix hydration with {@html} and components in <svelte:head> (#4533, #6463, #7444)
• Support scoped style for <svelte:element> (#7443)
• Improve error message for invalid value for <svelte:component this={...}> (#7550)
• Improve error message when using logic blocks or tags at invalid location (#7552)
• Warn instead of throwing error if <svelte:element> is a void tag (#7566)
• Supports custom elements in <svelte:element> (#7733)
• Fix calling component unmount if a component is mounted and then immediately unmounted (#7817)
• Do not generate a11y-role-has-required-aria-props warning when elements match their semantic role (#7837)
• Improve performance of custom element data setting in <svelte:element> (#7869)

3.50.1

• Add all global objects and functions as known globals (#3805, #7223)
• Fix regression with style manager (#7828)

3.50.0

• Add a11y warnings:
  • a11y-incorrect-aria-attribute-type: check ARIA state and property values (#6978)
  • a11y-no-abstract-role: check that ARIA roles are non-abstract (#6241)
  • a11y-no-interactive-element-to-noninteractive-role: check for non-interactive roles used on interactive elements (#5955)
  • a11y-role-has-required-aria-props: check that elements with role attribute have all required attributes for that role (#5852)
• Add ComponentEvents convenience type (#7702)
• Add SveltePreprocessor utility type (#7742)
• Enhance action typings (#7805)
• Remove empty stylesheets created from transitions (#4801, #7164)
• Make a11y-label-has-associated-control warning check all descendants for input control (#5528)
• Only show lowercase component name warnings for non-HTML/SVG elements (#5712)
• Disallow invalid CSS selectors starting with a combinator (#7643)
• Use Node.parentNode instead of Node.parentElement for legacy browser support (#7723)
• Handle arrow function on <slot> inside <svelte:fragment> (#7485)
• Improve parsing speed when encountering large blocks of whitespace (#7675)
• Fix class: directive updates in aborted/restarted transitions (#7764)

3.49.0

• Improve performance of string escaping during SSR (#5701)
• Add ComponentType and ComponentProps convenience types (#6770)
• Add support for CSS @layer (#7504)
• Export CompileOptions from svelte/compiler (#7658)
• Fix DOM-less components not being properly destroyed (#7488)
• Fix class: directive updates with <svelte:element> (#7521, #7571)
• Harden attribute escaping during SSR (#7530)

3.48.0

• Allow creating cancelable custom events with createEventDispatcher (#4623)
• Support {@const} tag in {#if} blocks #7241
• Return the context object in setContext #7427
• Allow comments inside {#each} blocks when using animate: (#3999)
• Fix |local transitions in {#key} blocks (#5950)
• Support svg namespace for {@html} (#7002, #7450)
• Fix {@const} tag not working inside a component when there's no let: #7189
• Remove extraneous leading newline inside <pre> and <textarea> (#7264)
• Fix erroneous setting of textContent for <template> elements (#7297)
• Fix value of let: bindings not updating in certain cases (#7440)
• Fix handling of void tags in <svelte:element> (#7449)
• Fix handling of boolean attributes in <svelte:element> (#7478)
• Add special style scoping handling of [open] selectors on <dialog> elements (#7495)

3.47.0

• Add support for dynamic elements through <svelte:element> (#2324)
• Miscellaneous variable context fixes in {@const} (#7222)
• Fix {#key} block not being reactive when the key variable is not otherwise used (#7408)
• Add Symbol as a known global (#7418)

3.46.6

• Actually include action TypeScript interface in published package (#7407)

3.46.5

• Add TypeScript interfaces for typing actions (#6538)
• Do not generate unused-export-let warning inside <script context="module"> blocks (#7055)
• Do not collapse whitespace-only CSS vars (#7152)
• Add aria-description to the list of allowed ARIA attributes (#7301)
• Fix attribute escaping during SSR (#7327)
• Prevent .innerHTML optimization from being used when style: directive is present (#7386)

3.46.4

• Avoid maximum call stack size exceeded errors on large components (#4694)
• Preserve leading space with preserveWhitespace: true (#4731)
• Preserve leading space in <pre> tags (#6437)
• Improve error message when trying to use style: directives on inline components (#7177)
• Add FormData as a known global (#7199)
• Mark css/instance/module AST properties as optional in types (#7204)

3.46.3

• Ignore whitespace in {#each} blocks when containing elements with animate: (#5477)
• Throw compiler error when variable in context="instance" collides with import in context="module" (#7090)
• Fix compiler crash when {@const} contains arrow functions (#7134)

3.46.2

• Export FlipParams interface from svelte/animate (#7103)
• Fix style: directive reactivity inside {#each} block (#7136)

3.46.1

• Handle style:kebab-case directives (#7122)
• Improve AST produced for style: directives (#7127)

3.46.0

• Implement {@const} tag (RFC #33, #6413)
• Implement style: directive (RFC #42, #5923)
• Fix style manager conflicts when using multiple Svelte instances (#7026)
• Fix hydration when using {@html} (#7115)

3.45.0

• Fix non-boolean attribute rendering in SSR to render truthy values as-is (#6121)
• Fix binding to a member expression also invalidating the member property (#6921)
• Fix default values in {#each}/etc. destructurings not being considered references for the purposes of compiler warnings (#6964)
• Fix {:else if} value incorrectly being cached (#7043)
• Add a11y-no-redundant-roles warning (#7067)
• Fix code generation error with arrow functions whose bodies are object destructuring assignments (#7087)

3.44.3

• Fix bind:this binding inside onMount for manually instantiated component (#6760)
• Prevent cursor jumps with one-way binding for other type="text"-like <input>s (#6941)
• Exclude async loops from loopGuardTimeout (#6945)

3.44.2

• Fix overly restrictive preprocessor types (#6904)
• More specific typing for crossfade function - returns a tuple, not an array (#6926)
• Add URLSearchParams as a known global (#6938)
• Add types field to exports map (#6939)

3.44.1

• Fix code generation when a multi-line return statement contains comments (code-red#36)
• Fix code generation when for/if/while statements have empty bodies (#6884)

3.44.0

• Add enableSourcemap compiler option (#6835)

3.43.2

• Fix regression where user-specified imports were not rewritten according to the sveltePath option (#6834)

3.43.1

• Prevent a rejecting promise used in {#await} during SSR from appearing as an unhandled rejection (#6789)

3.43.0

• Use export map to expose no-op versions of lifecycle functions for SSR (#6743)
• Prefer context passed to component constructor, even when running synchronously in another component (#6753)
• Handle preprocessors that return empty sourcemaps (#6757)

3.42.6

• Hide private preprocess typings (#6622)
• Fix reactive function in {:else if} expression not being properly re-run (#6727)

3.42.5

• In draw transition, account for stroke-linecap in determining length (#4540)
• Fix regression with destructuring assignments with default values (#6699)

3.42.4

• Only apply optimized src attribute handling when in an html namespace (#6575)
• Fix styles for transitions and animations being attached to the wrong document in <iframe>s (#6637)
• Fix <select> with a {...spread} attribute that didn't provide a value key getting its value improperly unset (#6675)

3.42.3

• Add BigInt as a known global (#6671)
• Fix regression where onDestroy in svelte/ssr was improperly a no-op (#6676)

3.42.2

• Collapse whitespace in class and style attributes (#6004)
• Deselect all <option>s in a <select> where the bound value doesn't match any of them (#6126)
• In hydrated components, only rely on helpers for creating the types of elements present in the component (#6555)
• Add HTMLElement and SVGElement as known globals (#6643)
• Account for scaling in flip animations (#6657)

3.42.1

• Fix regression with reordering keyed {#each} blocks when compiling with hydration enabled (#6561)

3.42.0

• Allow use:actions to be used on <svelte:body> (#3163)
• Improve parser errors for certain invalid components (#6259, #6288)
• Fix paths in generator JS sourcemaps to be relative (#6598)
• Fix overzealous warnings about context="module" variables not being reactive (#6606)

3.41.0

• Support export { ... } from syntax in components (#2214)
• Support export let { ... } = syntax in components (#5612)
• Support {#await ... then/catch} without a variable for the resolved/rejected value (#6270)

3.40.3

• Fix <slot> data when a transition is cancelled before completing (#5394)
• Fix destructuring into variables beginning with $ so that they result in store updates (#5653)
• Fix in: transition configuration not properly updating when it's changed after its initial creation (#6505)
• Fix applying :global() for > selector combinator (#6550)
• Fix mounting component at detached DOM node (#6567)

3.40.2

• Fix dynamic autofocus={...} attribute handling (#4995)
• Add filename to combined source map if needed (#6089)
• In AST, parse empty attribute values as an empty string (#6286)
• Fix tracking whether transition has started (#6399)
• Fix incorrect scoping of :global() selectors (#6550)

3.40.1

• Fix store reactivity regression when using reactive statements (#6557)

3.40.0

• Support rendering a component in a shadow DOM (#5869)
• Fix :root selector being erroneously scoped to component (#4767)
• Fix .end in AST for expressions inside attributes (#6258)
• Fix one-way <select> binding when it has a spread attribute (#6433)
• Various hydration improvements and fixes (#6449)
• Use smaller versions of internal helpers when compiling without hydration support (#6462)
• Fix two-way binding of values when updating through synchronous component accessors (#6502)

3.39.0

• Support bind:group in SSR (#4621)
• Add a11y warning a11y-mouse-events-have-key-events which checks that mouseover/mouseout are accompanied by focus/blur event handlers (#5938)
• Make it possible to silence more warnings (#5954)
• Add |trusted event modifier (#6137)
• Add varsReport compiler option to include all variables reference in the component in the variables report (#6192)
• Add errorMode compiler option to try to continue compiling when an error is detected (#6194)
• Expose svelte/ssr which exports lifecycle methods as no-ops (#6416)
• Add getAllContexts (#6447)
• Throw proper error for export default function() {} and export default class {} rather than crashing the compiler (#3275)
• Fix SSR rendering of falsy input values (#4551)
• Fix preserveComments in SSR mode (#4730)
• Do not warn if context="module" variables are not the only dependencies in reactive statements (#5954)
• Stop checking a11y-media-has-caption a11y warning on <audio> elements (#6054)
• Fix erroneous "unknown prop" warning when using slot on a component (#6065)
• Add sourcemaps to all HTML elements (#6092)
• Relax derived function signature (#6178)
• Throw compiler error when passing empty directive names (#6299)
• Fix compiler error when using :where() inside :global() (#6434)
• Fix ordering of elements in keyed {#each} (#6444)
• Remove deprecated a11y warning a11y-no-onchange warning (#6457)
• Fix :global() with pseudo element not being seen as global (#6468)
• Allow :global() to contain multiple selectors when it is not part of a larger selector (#6477)
• Make <script> and <style> end tag parsing more robust (#6511)

3.38.3

• Speed up hydration by reducing amount of element reorderings (#4308)
• Fix escaping attribute values when using a spread in SSR (#5756)
• Throw compiler error when :global() contains multiple selectors (#5907)
• Give explicit error rather than crashing when an attribute shorthand {} is empty (#6086)
• Make <textarea> end tag parsing more robust (#6276)
• Fix :global(...):some-pseudoclass selectors not being seen as global (#6306)
• Fix type signatures of writable and readable so it's possible to call them without arguments (#6291, #6345)
• Preserve this in bubbled events (#6310)
• Fix slot props not updating when transition is aborted (#6386)
• Fix generic props relationship in SvelteComponentTyped (#6400)

3.38.2

• Revert hydration optimisation for the time being (#6279)

3.38.1

• Fix hydration regression (#6274)

3.38.0

• Avoid recreating DOM elements during hydration (#1067)
• Support passing CSS custom properties to component (#5628)
• Support :global() as part of compound CSS selectors (#6222)
• Fix updating <slot> contents when there's an aborted transition (#3542)
• Fix setting boolean attributes on custom elements (#5951)
• Add missing function overload for derived to allow explicitly setting an initial value for non-async derived stores (#6172)
• Fix dynamic href values erroneously triggering a11y warnings (#5990)
• Fix scope leak when updating an {#await} block (#6173)
• Pass full markup source to script/style preprocessors (#6169)
• Fix crossfade types to mark fallback as optional (#6201)
• Add missing "context" typing to SvelteComponent constructor options (#6236)
• Don't automatically switch to svg namespace when in foreign namespace (#6257)

3.37.0

• Allow root-level context to be passed to the component constructor (#6032)

3.36.0

• Add this: void typing to store functions (#6094)
• Export Spring, Tweened and EasingFunction interfaces (#6070, #6056)
• Export interfaces for transition parameters (#5207)
• Export store's useful TypeScript definitions (#5864)
• Fix previous breaking change to svelte/preprocess types location (#6100)
• Fix missing slotted elements in AST (#6066)

3.35.0

• Implement slotted components and <svelte:fragment slot="..."> (#1037, #2079)
• Fix reactivity bug where slot="..." is specified after attributes that should be reactive (#5626)

3.34.0

• Add a cssHash option for controlling the classname used for CSS scoping (#570)

3.33.0

• In custom elements, call onMount functions when connecting and clean up when disconnecting (#1152, #2227, #4522)
• Allow destructured defaults to refer to other variables (#5066)
• Do not emit contextual-store warnings for function parameters or declared variables (#6008)

3.32.3

• Fix removal of lone :host selectors (#5982)

3.32.2

• Fix unnecessary additional invalidation with <Component bind:prop={obj.foo}/> (#3075, #4447, #5555)
• Fix scoping of selectors with :global() and ~ sibling combinators (#5499)
• Fix removal of :host selectors as unused when compiling to a custom element (#5946)

3.32.1

• Warn when using module variables reactively, and close weird reactivity loophole (#5847)
• Throw a parser error for class: directives with an empty class name (#5858)
• Fix extraneous store subscription in SSR mode (#5883)
• Don't emit update code for class: directives whose expression is not dynamic (#5919)
• Fix type inference for derived stores (#5935)
• Make parameters of built-in animations and transitions optional (#5936)
• Make SvelteComponentDev typings more forgiving (#5937)
• Fix foreign elements incorrectly disallowing bind:this (#5942)

3.32.0

• Allow multiple instances of the same action on an element (#5516)
• Support foreign namespace, which disables certain HTML5-specific behaviour and checks (#5652)
• Support inline comment sourcemaps in code from preprocessors (#5854)

3.31.2

• Rework SSR store handling to subscribe and unsubscribe as in DOM mode (#3375, #3582, #3636)
• Fix error when removing elements that are already transitioning out (#5789, #5808)
• Fix duplicate content race condition with {#await} blocks and out transitions (#5815)
• Deconflict variable names used for contextual actions (#5834)

3.31.1

• Fix scrolling of element with resize listener by making the <iframe> have z-index: -1 (#5448)
• Fix location of automatically declared reactive variables (#5749)
• Warn when using className or htmlFor attributes (#5777)
• Fix checkbox bind:group in keyed {#each} where the array can be reordered (#5779)
• Fix checkbox bind:group in nested {#each} contexts (#5811)
• Add graphics roles as known ARIA roles (#5822)
• Fix local transitions if a parent has a cancelled outro transition (#5829)
• Support use:obj.some.deep.function as actions (#5844)

3.31.0

• Use a separate SvelteComponentTyped interface for typed components (#5738)

3.30.1

• Support consuming decoded sourcemaps as created by the source-map library's SourceMapGenerator (#5722)
• Actually export hasContext (#5726)

3.30.0

• Add a typed SvelteComponent interface (#5431)
• Support spread into <slot> props (#5456)
• Fix setting reactive dependencies which don't appear in the template to undefined (#5538)
• Support preprocessor sourcemaps during compilation (#5584)
• Fix ordering of elements when using {#if} inside {#key} (#5680)
• Add hasContext lifecycle function (#5690)
• Fix missing walk types in svelte/compiler (#5696)

3.29.7

• Include ./register in exports map (#5670)

3.29.6

• Include ./package.json in export map (#5659)

3.29.5

• Fix $$props and $$restProps when compiling to a custom element (#5482)
• Include an export map in package.json (#5556)
• Fix function calls in <slot> props that use contextual values (#5565)
• Fix handling aborted transitions in {:else} blocks (#5573)
• Add Element and Node to known globals (#5586)
• Fix $$slots when compiling to custom elements (#5594)
• Fix internal imports so that we're exposing a valid ES module (#5617)

3.29.4

• Fix code generation error with ?? alongside logical operators (#5558)

3.29.3

• Hopefully actually republish with proper UMD build for use in the REPL

3.29.2

• Republish with proper UMD build for use in the REPL

3.29.1

• Fix compiler hanging on <slot slot="..."> (#5475)
• Fix types on get function in svelte/store (#5483)
• Add missing end field on ASTs for non-top-level <style> elements (#5487)
• Fix {#if} inside {#await} with destructuring (#5508)
• Fix types on lifecycle hooks (#5529)

3.29.0

• Support <slot slot="..."> (#2079)
• Fix unmounting components with a bidirectional transition with a delay (#4954)
• Add types to get function in svelte/store (#5269)
• Add a warning when a component looks like it's trying to use another component without beginning with a capital letter (#5302)
• Add EventSource to known globals (#5463)
• Fix compiler exception with ~/+ combinators and {...spread} attributes (#5465)

3.28.0

• Add {#key} block for keying arbitrary content on an expression (#1469)

3.27.0

• Add |nonpassive event modifier, explicitly passing passive: false (#2068)
• Scope CSS selectors with ~ and + combinators (#3104)
• Fix keyed {#each} not reacting to key changing (#5444)
• Fix destructuring into store values (#5449)
• Fix erroneous missing-declaration warning with use:obj.method (#5451)

3.26.0

• Support use:obj.method as actions (#3935)
• Support _ as numeric separator (#5407)
• Fix assignments to properties on store values (#5412)
• Add special style scoping handling of [open] selectors on <details> elements (#5421)
• Support import.meta in template expressions (#5422)

3.25.1

• Fix specificity of certain styles involving a child selector (#4795)
• Fix transitions that are parameterised with stores (#5244)
• Fix scoping of styles involving child selector and * (#5370)
• Fix destructuring which reassigns stores (#5388)
• Fix {#await}s with no {:catch} getting stuck unresolved if the promise rejects (#5401)

3.25.0

• Use null rather than undefined for coerced bound value of <input type="number"> (#1701)
• Expose object of which slots have received content in $$slots (#2106)
• Correctly disallow using lifecycle hooks after synchronous component initialisation (#4259, #4899)
• Re-throw an unhandled rejection when an {#await} block with no {:catch} gets a rejection (#5129)
• Add types to createEventDispatcher (#5211)
• In SSR mode, do not automatically declare variables for reactive assignments to member expressions (#5247)
• Include selector in message of unused-css-selector warning (#5252)
• Fix using <Namespaced.Component/>s in child {#await}/{#each} contexts (#5255)
• Fix using <svelte:component> in {:catch} (#5259)
• Fix setting one-way bound <input> value to undefined when it has spread attributes (#5270)
• Fix deep two-way bindings inside an {#each} involving a store (#5286)
• Use valid XHTML for elements that are optimised and inserted with .innerHTML (#5315)
• Fix reactivity of $$props in slot fallback content (#5367)

3.24.1

• Prevent duplicate invalidation with certain two-way component bindings (#3180, #5117, #5144)
• Fix reactivity when passing $$props to a <slot> (#3364)
• Fix transitions on {#each} {:else} (#4970)
• Fix unneeded invalidation of $$props and $$restProps (#4993, #5118)
• Provide better compiler error message when mismatched tags are due to autoclosing of tags (#5049)
• Add a11y-label-has-associated-control warning (#5074)
• Add a11y-media-has-caption warning (#5075)
• Fix bind:group when using contextual reference (#5174)

3.24.0

• Support nullish coalescing (??) and optional chaining (?.) operators (#1972)
• Support import.meta (#4379)
• Fix only setting <input> values when they're changed when there are spread attributes (#4418)
• Fix placement of {@html} when used at the root of a slot, at the root of a component, or in <svelte:head> (#5012, #5071)
• Fix certain handling of two-way bound contenteditable elements (#5018)
• Fix handling of imported value that is used as a store and is also mutated (#5019)
• Do not display a11y-missing-content warning on elements with contenteditable bindings (#5020)
• Fix handling of this in inline function expressions in the template (#5033)
• Fix collapsing HTML with static content (#5040)
• Prevent use of $store at compile time when top-level store has been shadowed (#5048)
• Update <select> with one-way value binding when the available <option>s change (#5051)
• Fix published tweened types so the .set() and .update() options are optional (#5062)
• Fix contextual bind:this inside {#each} block (#5067)
• Preprocess self-closing <script> and <style> tags (#5080)
• Fix types for animation- and transition-related param objects so each param is optional (#5083)

3.23.2

• Fix bind:group inside {#each} (#3243)
• Don't crash when using an arrow function as a statement (#4617)
• Deconflict bind:this variable (#4636)

3.23.1

• Fix checkbox bind:group when multiple options have the same value (#4397)
• Fix bind:this to the value of an {#each} block (#4517)
• Fix reactivity when assigning to contextual {#each} variable (#4574, #4744)
• Fix binding to contextual {#each} values that shadow outer names (#4757)
• Work around EdgeHTML DOM issue when removing attributes during hydration (#4911)
• Throw CSS parser error when :global() does not contain a selector (#4930)

3.23.0

• Update <select> with bind:value when the available <option>s change (#1764)
• Add muted binding for media elements (#2998)
• Fix inconsistencies when setting a two-way bound <input> to undefined (#3569)
• Fix setting <select multiple> when there are spread attributes (#4392)
• Fix let-less <slot> with context overflow (#4624)
• Fix resize listening on certain older browsers (#4752)
• Add a11y-no-onchange warning (#4788)
• Fix use: actions being recreated when a keyed {#each} is reordered (#4693)
• Fix {@html} when using tags that can only appear inside certain tags (#4852)
• Fix reactivity when binding directly to {#each} context (#4879)

3.22.3

• Support default values and trailing commas in destructuring {#await} (#4560, #4810)
• Fix handling of tweened store when set using duration: 0 (#4799, #4846)
• Fix setting value attribute with bind:group and attribute spread (#4803)
• Fix issue with compound {#if} block involving static condition, dynamic condition, and inline component (#4840)
• Update a11y warnings per ARIA 1.2 working draft (#4844)

3.22.2

• Fix compiler exception with a11y-img-redundant-alt and value-less alt attribute (#4777)

3.22.1

• Fix compiler exception with a11y-img-redundant-alt and dynamic alt attribute (#4770)

3.22.0

• Fix misaligned line numbers in source maps (#3906)
• Make setting a tweened store using duration: 0 instantly update the value (#4399)
• Fix reactivity with imported values that are then mutated (#4555)
• Fix contextual dynamic bind:this inside {#each} block (#4686)
• Do not display a11y warning about missing href for <a> with name or id (#4697)
• Disable infinite loop guard inside generators (#4698)
• Display a11y-invalid-attribute warning for href="javascript:..." (#4733)
• Implement a11y-img-redundant-alt warning (#4750)
• Fix variable name conflict with component called <Anchor> (#4768)

3.21.0

• Support dimension bindings in cross-origin environments (#2147)
• Fix several related outro bugs (#3202, #3410, #3685, #4620, #4630)
• Try using globalThis rather than globals for the benefit of non-Node servers and web workers (#3561, #4545)
• Support {#await ... catch ...} syntax shorthand (#3623)
• Fix attaching of JS debugging comments to HTML comments (#4565)
• Fix <svelte:component/> within <slot/> (#4597)
• Fix bug with updating simple {#if} blocks (#4629)
• Fix issues with <input type="number"> updates (#4631, #4687)
• Prevent illegal attribute names (#4648)
• Fix {#if} block directly within <slot/> (#4703)

3.20.1

• Fix compiler regression with slots (#4562)

3.20.0

• Allow destructuring in {#await} blocks (#1851)
• Allow <svelte:self> to be used in a slot (#2798)
• Expose object of unknown props in $$restProps (#2930)
• Prevent passing named slots other than from the top level within a component (#3385)
• Allow transitions and animations to work within iframes (#3624)
• Fix initialising slot fallbacks when unnecessary (#3763)
• Disallow binding directly to const variables (#4479)
• Fix re-attaching event handlers on keyed {#each} blocks (#4491)
• Fix updating keyed {#each} blocks with {:else} (#4536, #4549)
• Fix hydration of top-level content (#4542)

3.19.2

• In dev mode, display a runtime warning when a component is passed an unexpected slot (#1020, #1447)
• In vars array, correctly indicate whether module variables are mutated or reassigned (#3215)
• Fix spread props not updating in certain situations (#3521, #4480)
• Use the fallback content for slots if they are passed only whitespace (#4092)
• Fix bitmask overflow for {#if} blocks (#4263)
• In dev mode, check for unknown props even if the component has no writable props (#4323)
• Exclude global variables from $capture_state (#4463)
• Fix bitmask overflow for slots (#4481)

3.19.1

• Do not treat modifications to $$props as updates to a store called $props (#4368)
• Deconflict value parameter name used in contextual bindings (#4445)
• Fix dev mode validation of {#each} blocks using strings (#4450)

3.19.0

• Fix indirect bindings involving elements with spreads (#3680)
• $capture_state/$inject_state now act on the component's entire state, rather than its props (#3822)
• Warn when using <Foo/> and Foo is dynamic (#4331)
• Display compilation warnings in svelte/register in dev mode (#4364)
• Fix unneeded updating of keyed each blocks (#4373)
• Throw runtime error in dev mode for non-array-like values in {#each} blocks (#4408)

3.18.2

• Fix binding to module-level variables (#4086)
• Improve parsing error messages when there is a pending unclosed tag (#4131)
• Disallow attribute/prop names from matching two-way-bound names or {shorthand} attribute/prop names (#4325)
• Improve performance of flush() by not using .shift() (#4356)
• Permit reserved keywords as destructuring keys in {#each} (#4372)
• Disallow reserved keywords in {expressions} (#4372)
• Fix code generation error with precedence of arrow functions (#4384)
• Fix event handlers that are dynamic via reactive declarations or stores (#4388)
• Fix invalidation in expressions like ++foo.bar (#4393)

3.18.1

• Fix code generation error with adjacent inline and block comments (#4312)
• Fix detection of unused CSS selectors that begin with a :global() but contain a scoped portion (#4314)

3.18.0

• Fix infinite loop when instantiating another component during onMount (#3218)
• Make autosubscribing to a nullish store a no-op (#2181)

3.17.3

• Fix updating a <slot> inside an {#if} or other block (#4292)
• Fix using RxJS observables in derived stores (#4298)
• Add dev mode check to disallow duplicate keys in a keyed {#each} (#4301)
• Fix hydration of <title> when starting from SSR-generated code with hydratable: true (#4310)

3.17.2

• Fix removing attributes during hydration (#1733)
• Disallow two-way binding to a variable declared by an {#await} block (#4012)
• Allow access to let: variables in sibling attributes on slot root (#4173)
• Fix ~= and class selector matching against values separated by any whitespace characters (#4242)
• Fix code generation for awaited expressions that need parentheses (#4267)
• Preserve JavaScript comments from the original component source where possible (#4268)
• Add some more known globals (#4276)
• Correctly apply event modifiers to <svelte:body> events (#4278)

3.17.1

• Only attach SSR mode markers to a component's <head> elements when compiling with hydratable: true (#4258)

3.17.0

• Remove old <head> elements during hydration so they aren't duplicated (#1607)
• Prevent text input cursor jumping in Safari with one-way binding (#3449)
• Expose compiler version in dev events (#4047)
• Don't run actions before their element is in the document (#4166)
• Fix reactive assignments with destructuring and stores where the destructured value should be undefined (#4170)
• Fix hydrating {:else} in {#each} (#4202)
• Do not automatically declare variables in reactive declarations when assigning to a member expression (#4212)
• Fix stringifying of attributes in SSR mode when there are spread attributes (#4240)
• Only render one <title> in SSR mode when multiple components provide one (#4250)

3.16.7

• Also apply actions in the order they're given along with other directives (#2446, #4156)
• Check whether a dynamic event handler is a function before calling it (#4090)
• Correctly mark event handlers as dynamic when they involve an expression used in a bind: elsewhere (#4155)

3.16.6

• Fix CSS specificity bug when encapsulating styles (#1277)
• Apply directives in the order they're given (#2446)
• Fix destructuring in let: directives (#2751)
• Preserve whitespace around <tspan>s in <svg>s (#3998)

3.16.5

• Better fix for cascading invalidations and fix some regressions (#4098, #4114, #4120)

3.16.4

• Fix slots with props not propagating through to inner slots (#4061)
• Fix noting autosubscribed stores as referenced in vars for tooling (#4081)
• Fix cascading invalidations in certain situations (#4094)

3.16.3

• Fix bitmask overflow when using slotted components (#4077)
• Remove unnecessary $$invalidate calls from init block (#4018)

3.16.2

• Handle slot updates when parent component has a bitmask overflow (#4078)

3.16.1

• Fix unused export warning for props used as stores (#4021)
• Fix {:then} without resolved value containing {#each} (#4022)
• Fix incorrect code generated with loopGuardTimeout (#4034)
• Fix handling of bitmask overflow and globals (#4037)
• Fix {:then} containing {#if} (#4044)
• Fix bare imports in format: 'cjs' output mode (#4055)
• Warn when using a known global as a component name (#4070)

3.16.0

• Use bitmasks to track changes (#3945)
• Fix heisenbug with component styles (#3977)
• Do not warn about missing expected props for export function foo() {} (#3954)
• Fix context="module" exports with the same name as an instance variable (#3983)
• Fix binding to contextual values from {#each} blocks referring to global variables (#3992)
• Use requestAnimationFrame callback argument for smoother transitions (#4014)
• Fix listen_dev argument order (#4016)

3.15.0

• Hide commented sections from preprocessors (#3894)
• Add seeking and ended bindings to media elements (#3650)
• Add videoWidth and videoHeight bindings to video elements (#3927)
• Fix for dynamic event handlers (#3934)
• Handle scale transforms when using the flip animation (#3555)
• Fix some code generation bugs (#3929, #3939)
• Add aria-hidden="true" to objects generated when adding resize-listeners, to improve accessibility (#3948)

3.14.1

• Deconflict block method names with other variables (#3900)
• Fix entity encoding issue in text nodes with constant expressions (#3911)
• Make code for unknown prop warnings compatible with older js engines (#3914)

3.14.0

• Add loopGuardTimeout option that augments for/while loops to prevent infinite loops, primarily for use in the REPL (#3887)
• Keep component bindings in sync when changed in reactive statements (#3382)
• Update attributes before bindings (#3857)
• Prevent variable naming conflict (#3899)

3.13.0

• New structured code generation, which eliminates a number of edge cases and obscure bugs (#3539)

Also:

• Fix {#each} context not shadowing outer scope when using bind: (#1565)
• Fix edge cases in matching selectors against elements (#1710)
• Fix several bugs related to interaction of {...spread} attributes with other features (#2721, #2916, #3421, #3681, #3764, #3790)
• Allow exiting a reactive block early with break $ (#2828)
• Fix binding to props that have been renamed with export { ... as ... } (#3508)
• Fix application of style scoping class in cases of ambiguity (#3544)
• Check attributes have changed before setting them to avoid image flicker (#3579)
• Fix generating malformed code for {@debug} tags with no dependencies (#3588)
• Fix generated code in specific case involving compound ifs and child components (#3595)
• Fix bind:this binding to a store (#3591)
• Use safer HTMLElement check before extending class (#3608)
• Add location as a known global (#3619)
• Support {#await} with {:catch} but no {:then} (#3623)
• Clean up dead code emitted for <slot/>s (#3631)
• Fix tracking of dependencies of compound assignments in reactive statements (#3634)
• Flush changes in newly attached block when using {#await} (#3660)
• Throw exception immediately when calling createEventDispatcher() after component instantiation (#3667)
• Fix globals shadowing contextual template scope (#3674)
• Fix <svelte:window> bindings to stores (#3832)
• Deconflict generated var names with builtins (#3724)
• Allow spring/tweened values to be initially undefined (#3761)
• Warn if using <svelte:options tag="..."> without customElement: true option (#3782)
• Add Event to list of known globals (#3810)
• Throw helpful error on empty CSS declaration (#3801)
• Support easing param on fade transition (#3823)
• Generate valid names from filenames with unicode characters (#3845)
• Don't generate any code for markup-less components (#2200)
• Deconflict with internal name block (#3854)
• Set attributes before bindings, to prevent erroneous assignments to input.files (#3828)
• Smarter unused CSS detection (#3825)
• Allow dynamic event handlers (#3040)
• Prevent erroneous "undefined" class name (#3876)
• Prevent resetting of src attribute unless changed (#3579)
• Prevent hydration of void element 'children' (#3882)
• Hoist globals even if mentioned in <script> block (#3745)

3.12.1

• Escape @ symbols in props, again (#3545)

3.12.0

• Fire events on document in development to facilitate dev tooling (#3005)
• Remove old props when the keys in spread props are removed (#2282)

3.11.0

• $capture_state and $inject_state HMR hooks in dev mode (#3148)
• Allow unclosed tags inside if/each/etc blocks (#2807)
• Invalidate unreferenced store values inside <script> (#3537)
• Print null text when hydrating (#3379)

3.10.1

• Preserve reactivity inside if block heads etc (#3512)
• Fix store bindings inside each blocks (#3455)
• Generate correct code for if-else blocks with static conditions (#3505)
• Avoid generating unnecessary component update code (#3526)
• Make bind:currentTime more reliable (#3524)
• Prevent errors when setting spread props on SVG elements (#3522)

3.10.0

• Add blur transition (#3477)
• Prevent <input type="number"> edge case with spread props (#3426)
• Robustify cyclical dependency detection, improve errors (#3459)

3.9.2

• Fix handling of additional @-rules in style blocks (#2995)
• Fix if blocks with complex but static conditions (#3447)

3.9.1

• Only update style properties if necessary (#3433)
• Only update if/await blocks if necessary (#2355)
• Set context correctly inside await blocks (#2443)
• Handle !important inline styles (#1834)
• Make index references reactive in event handlers inside keyed each blocks (#2569)

3.9.0

• Support is attribute on elements, with a warning (#3182)
• Handle missing slot prop (#3322)
• Don't set undefined/null input values, unless previous value exists (#1233)
• Fix style attribute optimisation bailout (#1830)

3.8.1

• Set SVG namespace for slotted elements (#3321)

3.8.0

• Add self event modifier (#3372)
• Generate valid code when spreading literal (#3185)
• Coerce tag values to string before checking equality (#2290)

3.7.1

• Assume let variables are dynamic for slots (#3354)
• Allow transition functions to return nothing (#2246)

3.7.0

• Disable warnings via svelte-ignore comments (#3351)
• Throw if $ or $$... is referenced as global (#3272)
• Remount HTML tags correctly (#3329)
• Treat data attributes like other attributes (#3337)

3.6.11

• Handle reassigned RxJS observables (#3304)
• Remove commas from HTMLified attributes with multiple chunks (#3341)
• Prevent class on element with scoped styles from rendering as undefined (#3283)
• Allow references to index in key expression (#3274)
• Mark attribute selectors as used if corresponding binding exists (#3281)
• Preserve async/* when hoisting functions (#3179)
• Make raf a noop on server (#3324)
• Prevent erroneous a11y warning for image input with alt attribute (#3331)
• Add several well-known globals (#3316)

3.6.10

• Use change event for file inputs (#3226)
• Always fire reactive declarations with $$props (#3286)
• More conservative spread prop updates (#3289)
• Quote props if necessary in SSR mode (#3312)

3.6.9

• Always update derived stores with a derived input whose value does not change (#3191)

3.6.8

• Preserve global keyframes that don't match local elements (#3228)
• Fix spread/class: combination (#3242)
• Never scope :root selector (#3250)
• Prevent trailing commas in function arguments (#3255)

3.6.7

• Prevent corruption of outro callbacks with nested keyed each blocks (#3209)
• Prevent cursor jumping in bound input in Safari (#3199)
• Make resize listener object unfocusable (#3206)

3.6.6

• Prevent dynamic components being detached twice (#3113, #2086)

3.6.5

• Handle RxJS-style observables with get (#3153)
• Pass let values to bindings (#3140)
• Escape @ symbols in props (#3173)
• Scale crossfaded elements (#3175)

3.6.4

• Run onMount functions in correct order, and before initial afterUpdate functions (#2281)
• Fix code transformation for shorthand methods (#2906)
• Fix assignments in inline functions (#3038)

3.6.3

• Fix await block mounting inside removed if block (#1496)
• Update when element references are removed (#2034)
• Don't attempt to serialize non-string values in server-rendered bindings (#2135)
• Recognise dependencies in function expressions (#2693)
• Scope pseudo-class selectors without class/type (#1705)
• Allow nested at-rules (#3135)
• Allow attributes to contain = characters (#3149)

3.6.2

• Fix placement of each-else block (#2917)
• Make context accessible to bind:this (#2806)
• Pass hoisted values to slots (#2586)

3.6.1

• Fix escaping of @ in dev mode debug filename (#3114)

3.6.0

• Add innerHTML and textContent bindings for contenteditable elements (#2996)
• Fix destructuring assignments where targets are member expressions (#3092)
• Deconflict with used globals (#2963)
• Always run onDestroy functions, not just for detaching components (#3058)
• Fix scope analysis around catch clauses (#3064)
• Add error constructors to known globals (#3064)
• Always bail out of hoisting on encountering local state in function definition (#3044)
• Fix incorrect merging of top-level text nodes (#3027)
• Handle removal of components in each blocks without props (#3035)
• Only call subscriber once when resubscribing to a store (#3022)
• Check for existence of dynamic component before introing (#3054)
• Sanitize names of bubbled event handlers (#2923)

3.5.4

• Preserve whitespace at the boundaries of {#each} blocks (#713)
• Fix dynamic bind:this on components (#2333)
• Fix binding to values in a component when it uses $$props (#2725)
• Fix parsing ambiguous HTML entities (#3071)

3.5.3

• Don't double-destroy keyed each blocks with outros (#3055)

3.5.2

• Prevent duplicated outros causing errors (#3001)
• Fix automatic name generation (#2843)
• Fix .d.ts stubs (#3009)
• Don't strip non-breaking spaces (#3014)
• Fix requestAnimationFrame context (#2933)
• Allow space before attribute value (#3026)
• Remove null/undefined attributes (#1434)
• Fix whitespace in static markup (#3030)

3.5.1

• Accommodate webpack idiosyncrasies

3.5.0

• Update package folder structure (#2887)
• Support once modifier on component events (#2654)
• Allow empty <title> tags (#2980)
• Render textarea binding values inside element (#2975)
• Fix delayed animation glitch (#2871)
• Solve diamond dependencies problem with stores (#2660)
• Fix missing outros inside each blocks (#2689)
• Support animations without transitions (#2908)
• Add missing transition events (#2912)

3.4.4

• Publish type declaration files (#2874)
• Don't trigger updates for unreferenced values (#2865)
• Omit readonly bindings from SSR output (#2339)
• Prevent outdated animation CSS (#2871)
• Repair dynamic {@html ...} in head (#2880)
• Don't create unknown prop warnings for internal props, or if component has $$props (#2881)

3.4.3

• Add type declaration files for everything (#2842)
• Prevent svelte/store being bundled (#2786)
• Warn on unknown props in dev mode (#2840)
• Treat requestAnimationFrame as a no-op on the server (#2856)
• Add raw property to AST's Text nodes (#2714)
• Add <details bind:open> (#2854)

3.4.2

• Use empty string for empty data attributes (#2804)
• Support customElement: true with no <svelte:options> (#2821)
• Add docstrings to svelte/store (#2795)

3.4.1

• Handle non-falsy non-function return values from derivers (#2780)
• Allow spring to work server-side (#2773)

3.4.0

• Allow custom element to be defined without a tag (#2417)
• Fix parsing of quote marks inside attribute values (#2715)
• Convert svelte/store to TypeScript (#2733)
• Allow debug tags to include hoisted values (#2764)
• Parse error if attribute name is missing = (#1513)
• Allow reactive declarations to depend on mutated const values (#2728)

3.3.0

• Allow multiple event listeners on a single node (#2688)
• Allow derivers to return a cleanup function (#2553)
• Support namespaced components (<Foo.Bar/>) (#2743)

3.2.2

• Add window and document to expected globals (#2722)
• Prevent hoisting of functions that depend on reactive state (#2703)
• Generate correct code when slot has no changes (#2697)
• Prevent Object.prototype-related bugs (#2696)

3.2.1

• Use same comparison logic for derived as for other stores (#2644)
• Invalidate dependencies of reactive declarations (#2444)
• Fix instrumentation of auto-subscription self-assignments (#2681)
• Warn on non-top-level or module-context statements labeled with $: (#2176)

3.2.0

• Improve spring animations, and add hard/soft options (#2627)
• Expose parse and walk functions (#2661, #2534)
• Support array/object rest in each block destructuring patterns (#2647, #2658)
• Use setAttribute to change form property on form elements (#1742)
• Fix a11y warning when <figcaption> is non-direct descendant of <figure> (#2582)
• Squelch erroneous 'empty block' warnings (#1716)
• Fix IE9/10 error with insertBefore (#2573)
• Prevent $$scope from being spread onto an element (#2520)
• Resubscribe to stores that are assigned to in <script> (#2435)
• Allow reactive declarations to depend on const variables (#2285)
• Trigger store changes on UpdateExpression (#2625)
• Squelch missing prop warning if variable is initialised (#2635)
• Add alert, confirm and prompt to known globals (#2648)

3.1.0

• Allow store subscribe functions to return an object with an unsubscribe method, providing native RxJS support (#2549)

3.0.1

• Prevent text input cursor jumping in Safari (#2506)
• Allow assignments to member expressions (#2510)
• Prevent mutually dependent functions causing an infinite during hoisting (#2542)
• Reuse scheduler promise instead of creating new one each time (#2555)
• Various site/docs fixes

3.0.0

• Everything

2.15.4

• IE classList fix (#1868)

2.15.3

• Don't mutate AST

2.15.2

• Expose stats.props (#1837)

2.15.1

• Don't throw missing store error when store is declared in component (#1828)

2.15.0

• Event modifiers (#1088)
• Wheel and touch events are passive by default (#1088)
• Add <svelte:document> tag (#1484)
• Include binding values in server-rendered HTML (#1205)
• Remove attributes when value is undefined/null (#1434)
• Initialise window scroll from component data (#938)
• Remove references to unused properties in generated code (#1187)
• Add TypeScript definitions for store (#1207)
• Better error for missing store (#1807)

2.14.3

• Account for directive dependencies (#1793)
• Detach each block iterations in each blocks with no update method (#1795)

2.14.2

• Fix issue with nested {#if} blocks (#1780)

2.14.1

• Fix block insertion order regression (#1778)
• Fix blocks inside <svelte:head> (#1774)
• Better attribute parsing (#1772)
• Fix parse errors inside directives (#1788)

2.14.0

• Refactor internals (#1678)
• Deprecate onerror option (#1745)
• Handle edge cases where destroy is called before mount (#1653)
• Make scroll binding more efficient (#1579)
• Make 'readonly property' store error more informative (#1761)

2.13.5

• Fix missing dependencies in shorthand class directives (#1739)

2.13.4

• Support dynamic import() in template expressions

2.13.3

• Fix bug with keyed each blocks and nested components (#1706)

2.13.2

• Coalesce simultaneous store/component updates (#1520)
• Fix nested transitions preventing each block item removal (#1617)
• Add class directive shorthand and encapsulate styles (#1695)
• Prevent erroneous updates of bound inputs (#1699)

2.13.1

• Coerce second argument to toggleClass (#1685)

2.13.0

• Add class directive (#890)
• Remove sourcemaps from npm package (#1690)

2.12.1

• Allow actions to take any expression (#1676)
• Run transitions in component context (#1675)
• Correctly set select value on mount (#1666)
• Support {@debug} in SSR (#1659)
• Don't treat   as empty whitespace (#1658)
• Fix outros for if blocks with no else (#1688)
• Set style.cssText in spread attributes (#1684)

2.12.0

• Initialise actions on mount rather than hydrate (#1653)
• Allow nonexistent components to be destroyed (#1677)
• Pass AMD ID from CLI correctly (#1672)
• Minor AST tweaks (#1673, #1674)
• Reduce code duplication in component initialisation (#1670)

2.11.0

• Add --shared CLI option (#1649)
• Run first onstate before fragment is rendered (#1522)
• Exclude current computed prop from state object (#1544)

2.10.1

• Add sourcemaps to {@debug} tags (#1647)

2.10.0

• Add a {@debug} tag, for inspecting values in templates in dev mode (#1635)
• Fix dimension bindings in iOS (#1642)

2.9.11

• Pass props to custom elements rather than setting attributes, where appropriate (#875)
• Handle whitespace in lists consistently between SSR and DOM renderers (#1637)
• Improve error for invalid ref names (#1613)

2.9.10

• Handle null consistently in tags (#1598)
• Support object rest in computed properties (#1540)
• Always update dynamic components when expression changes (#1621)
• Encapsulate local styles inside global styles (#1618)

2.9.9

• Fix attribute name regex (#1623)

2.9.8

• Sanitize spread attributes in SSR — fixes vulnerability CVE-2018-6341 (#1623)

2.9.7

• Allow <input type=file bind:files> (#1608)
• Ensure child window exists before removing listener in addResizeHandler (#1600)
• Handle transitions in else block (#1589)

2.9.6

• Provide more useful error if SSR component attempts to render non-SSR component (#1605)

2.9.5

• Null out refs to dynamic components (#1596)

2.9.4

• Make identifier optional for then and catch blocks (#1507)
• Group outros correctly (#1575)

2.9.3

• Fix bug when an each block contains transitions but its else branch does not (#1559)
• If an event handler throws an exception, don't block all future calls to that handler (#1573)

2.9.2

• Fix conflict when using multiple if-else blocks, some of which use outros and some of which do not (#1580)
• Fix some cases where .innerHTML was being used to create child elements when it shouldn't (#1581)

2.9.1

• Use template.content instead of template where appropriate (#1571)

2.9.0

• Play outro transitions on <svelte:component> if nestedTransitions is true (#1568)
• Allow illegal identifiers to be component prop names, for e.g. spreading data-foo props (#887)
• Abort transition when node is detached (#1561)
• Only include transitionManager when necessary (#1514)

2.8.1

• Fix prefixed animation name replacement (#1556)

2.8.0

• Correctly set store on nested components (to parent store, not root store) (#1538)

2.7.2

• Prevent unnecessary remounts (#1527)
• Allow refs.* as callee (#1526)
• Handle empty lists when outroing (#1532)

2.7.1

• Fix spread props with multiple dependencies (#1515)

2.7.0

• Add __svelte_meta object to elements in dev mode, containing source info (#1499)
• Fix bind:online in dev mode (#1502)
• Update v1 warnings/errors (#1508)
• Transform prefixed keyframes (#1504)

2.6.6

• Fix nested transition bug (#1497)

2.6.5

• Handle cases where only some if block branches have outros (#1492)

2.6.4

• Web worker support (#1487)
• Update dynamic component bindings when component changes (#1489)

2.6.3

• Nested transitions respect skipIntroByDefault (#1460)
• Always create outro for top-level block (#1470)

2.6.2

• Fix spread+bindings on dynamic components (#1433)
• Abort in-progress animations, if a new one starts (#1458)
• Allow animations to be parameterised (#1462)

2.6.1

• Absolutely position outroing animated nodes (#1457)

2.6.0

• Add animate directive (#1454)
• Add skipIntroByDefault compiler option and intro: true init option (#1448)
• Add nestedTransitions compiler option (#1451)
• Component outros, if nestedTransitions is true (#1211)
• Allow transition functions to return a function, for inter-transition coordination (#1453)
• Pass 1 - t as second argument to transition functions (#1452)

2.5.1

• Add new ARIA attributes (#1436)
• Add Promise to whitelisted globals (#1441)
• Allow spaces around reserved keyword attributes (#1445)

2.5.0

• Support transitions in await blocks (#956)
• Abort outros if block is recreated (#1425)
• Wait until transitions have completed before removing styles (#648)
• Support event shorthand on dynamic components (#1427)
• Various codegen improvements (#1419, #1421, #1422, #1424)
• Correctly handle await blocks with no dynamic content (#1417)
• Allow spread props on elements with static attribute tests (#1429)

2.4.4

• Declare missing variable in Store (#1415)
• ALways declare spread levels (#1413)

2.4.3

• ref directives prevent HTMLified content (#1407)
• Store computed properties update components immediately upon declaration (#1327)

2.4.2

• Evaluate each key in child scope (#1397)
• Prevent false negatives and positives when detecting cyclical computed store properties (#1399)
• Only update dynamic component props (#1394)

2.4.1

• Fix DOM event context (#1390)

2.4.0

• Integrate CLI (#1360)
• Allow arbitrary destructuring for each block items, with binding (#1385)
• Each block keys can use arbitrary expressions (#703)
• bind:offsetWidth, bind:offsetHeight, bind:clientWidth and bind:clientHeight (#984)
• Leaner generated code for each blocks (#1287)

2.3.0

• Allow computed properties to have entire state object as dependency (#1303)
• Fix stats when options.generate is false (#1368)
• Assign custom methods to custom elements (#1369)
• Fix this value in custom event handlers (#1297)
• Re-evaluate each values lazily (#1286)
• Preserve outer context in await blocks (#1251)

2.2.0

• Internal refactoring (#1367)

2.1.1

• Report initial changed based on state, not expected props (#1356)
• Set state to empty object, not null, on destroy (#1354)
• Prevent stale state in component event handlers (#1353)

2.1.0

• Allow shorthand imports (#1038)
• Update spread props inside each blocks (#1337)

2.0.0

See the blog post for information on how to upgrade your apps

• New template syntax (#1318)
• Emit ES2015 code, not ES5 (#1348)
• Add onstate and onupdate hooks, remove component.observe method (#1197)
• Use destructuring syntax for computed properties (#1069
• Change signature of svelte.compile (#1298)
• Remove validate and Stylesheet from public API (#1348)
• Don't typecast numeric attributes (#657)
• Always compile with Store support, and cascading disabled (#1348)
• Remove unused hash property from AST (#1348)
• Rename loc property to start in warnings and errors (#1348)

1.64.1

• Fix computed properties in SSR renderer (#1349)

1.64.0

• Deprecate passing a string argument to component.get (#1347)

1.63.1

• Allow observe method to be overwritten

1.63.0

• Add onstate and onupdate lifecycle hooks and deprecate component.observe (#1197)
• Add on and fire to Store, deprecate onchange and observe (#1344)
• Require computed properties to have destructured argument in v2 mode (#1069)

1.62.0

• Add a code field to errors and warnings (#474)
• When using v2 syntax, do not use interpolation in non-root <style> tags (#1339)

1.61.0

• Support v2 syntax with parser: 'v2' option (#1318)

1.60.3

• Fix validation of multiple attributes on bound <select> elements (#1331)

1.60.2

• Fix order of insertions for keyed each blocks with siblings (#1306)
• Bail out of CSS DCE if element has spread attribute (#1300)
• Allow console etc in component events (#1278)
• Deconflict against inherited contexts (#1275)
• Make CSS DCE case insensitive (#1269)
• Error on dynamic multiple attribute for bound select (#1270)
• Allow custom events on <:Window> (#1268)

1.60.1

• Fix spread updates on dynamic components (#1307)

1.60.0

• Spread properties (#195)
• svelte.compile returns an object with { js, css, ast } properties, where js and css are { code, map } objects (#1298)
• Fixed broken compile errors when using Rollup (#1296)

1.59.0

• Deprecate teardown in custom event handlers (#531)
• Allow static content in keyed each block (#1291)
• Allow empty content in keyed each block (#1295)
• Only delete applicable transitions (#1290)

1.58.5

• Allow backtick string literals for svg, tag, and props properties (#1284)
• Fix removal of transition styles under Firefox (#1288)

1.58.4

• Fix initial state regression (#1283)

1.58.3

• Actions run in the context of the component (#1279)
• Set refs when mounting dynamic components (#1280)

1.58.2

• (1.58.1 failed to publish)

1.58.1

• Actions (#1247)
• Support preserveComments option in SSR mode (#1265)
• Fix performance regression (#1274)

1.58.0

• Fast row swapping (#588)
• Better error messages for invalid directives (#1242)
• Fix local context variable bugs (#1240, #1254)
• Skip missing property warnings for computed/global properties in dev mode (#1246)
• Add end position to warnings (#1250)

1.57.4

• Deconflict context names (#1229)
• Use setAttribute to set input types (#1209)
• Scale transition duration correctly (#1221)

1.57.3

• Fix scoped CSS on static child elements (#1223)

1.57.2

• Fix scoped CSS on SVG elements (#1224)

1.57.1

• Add each_value to contextProps (#1206)

1.57.0

• Use classes (not attributes) for style encapsulation, and base36-encode hashes (#1118)

1.56.4

• Allow component and state to be context names (#1213)
• Don't remove @supports rules when cascade: false (#1215)

1.56.3

• Top-level transitions work inside nested components (#1188)
• Always use internal _mount method (#1201)

1.56.2

• Null out key for children of keyed each blocks (#1202)

1.56.1

• Fix if-in-each bug (#1195)
• Cross-browser scrollX/scrollY support (#1175)

1.56.0

• Internal refactor (#1122)
• Use correct context for component events (#1184)
• Allow observing $foo in dev mode (#1181)
• Handle dynamic data in default slot (#1144)

1.55.1

• Fix cancellation of store onchange handlers (#1177)
• Write ["default"] instead of .default in legacy mode (#1166)
• Upgrade Acorn (#1182)
• Don't warn about capitalisation if options.name begins with non-alphabetical character (#1179)

1.55.0

• Add immutable compiler option for Svelte and runtime option for Store (#1146)
• Fix component store bindings (#1100)
• Fire oncreate when custom element is attached (#1117)
• Downgrade empty blocks to a warning (#1156)
• Error on unclosed comment (#1156)

1.54.2

• Prevent await blocks using stale state (#1131)
• Prevent erroneous missing data warnings for custom elements (#1065)
• Remove empty selectors in prod mode (#1138)
• Escape attribute values in SSR mode (#1155)
• Remove <noscript> elements in DOM mode (#1108)
• Allow hydration of non-root <script>/<style> tags (#1163)
• Allow interpolation in non-root <style> tags (#1163)

1.54.1

• Hoist destructured references (#1139)
• Add bind:volume for media elements (#1143)

1.54.0

• Run oncreate hooks depth-first, top-to-bottom (#1135)
• Render boolean attributes correctly in SSR mode (#1109)
• Add feed aria role to expected roles when doing a11y checks (#1124)
• More complete fix for case sensitive attributes (#1062)
• Handle CLRF line endings in await block comments (#1132)

1.53.0

• Base scoping selectors on <style> contents alone (#1091)

1.52.0

• Deconflict referenced globals (#1079)
• Validate contents of await blocks (#1061)
• Fire oncreate for components in await blocks (#1061)
• Automatically fix attribute casing (#1062)
• Fix escaping in <script> and <style> (#1082)
• Error if invalid characters are used in computed properties, and allow any valid identifier in props (#1083)
• Don't run a11y tests on components (#1110)
• Respect store option in SSR mode (#1107)

1.51.1

• Only escape <, > and & characters (#1082)

1.51.0

• Lock scroll bindings (#1071)
• Escape HTML entities when compiling to static HTML (#1066)
• Apply a11y warnings to SVG <a> attributes with xlink:href (#1008)

1.50.1

• Prevent main fragment being created twice in custom elements (#1064)

1.50.0

• Detect unused/misplaced components (#1039)
• Warn on unused event definitions/transitions (#1051)
• Remove whitespace inside <:Head> (#1026)
• Optimise <title> (#1027)
• Add bind: false option to disable two-way binding (#54)

1.49.3

• Return html from SSR compiler render().toString() methods (#1044)
• Correctly reinitialise dynamic components (#1040)
• Allow <option> outside <select> (#1022)
• Fix data references in await-block event handlers (#1032)

1.49.2

• Add store.umd.js (#967)
• Warn on use of this inside computed properties (#1033)

1.49.1

• Pass store to children in SSR mode (#1029)

1.49.0

• Support store as a component property (#1028)

1.48.0

• Added <:Head> component for injecting contents into document head (#1013))
• SSR render(...) method now returns a { html, css: { code, map }, head } object (#1013)
• SSR renderCss(...) method is deprecated (#1013)
• Add a preload function to components (#1015)
• Expose this.root on nested components (#1023)

1.47.2

• Deconflict computed properties against arguments to _recompute (#1012)
• Allow await blocks in slots (#1018)
• Allow components without slots to have whitespace as only child (#1007)
• Correctly set toString on CompileError (#1016)

1.47.1

• Sanitize filenames in SSR mode (#1005)

1.47.0

• Support dynamic import(...) inside <script> tags (#1003)

1.46.1

• await...then shorthand (#957)
• Allow dynamic components inside elements (#993)
• Don't use dataset on SVG nodes (#982)
• Fix erroneous <figcaption> a11y warning (#991)
• Handle empty classes when pruning unused selectors (#978)
• Better trimming of SSR'd output (#976)
• Don't add event to expectedProperties (#972)
• Emit error on bad set arguments in dev mode (#990)

1.46.0

• Pass filename through to preprocessors (#983)

1.45.0

• Dynamic components (#971)

1.44.2

• Fix await blocks with siblings (#974)
• Fix await blocks inside if blocks (#975)

1.44.1

• Fix bidirectional transitions that reference state (#962)

1.44.0

• Add svelte.preprocess (#181, #876)
• Add {{#await ...}} blocks (#654)

1.43.1

• Fix parameterised transitions (#962)
• Prevent boolean attributes breaking estree-walker expectations (#961)
• Throw error on cyclical store computations (#964)

1.43.0

• Export Store class to manage global state (#930)
• Recognise aria-current (#953)
• Support SSR register options including extensions (#939)
• Friendlier error for illegal contexts (#934)
• Remove whitespace around <:Window> components (#943)

1.42.1

• Correctly append items inside a slotted each block (#932)
• Fix <:Window bind:online/> (#936)
• Attach globals to state upon initialisation (#908)

1.42.0

• Implement indeterminate binding for checkbox inputs (#910)
• Use <option> children as value attribute if none exists (#928)
• Allow quoted property names in default export and sub-properties (#914)
• Various improvements to generated code for bindings

1.41.4

• Handle self-destructive bindings (#917)
• Prevent innerHTML with <option> elements (#915)
• Use dataset unless legacy is true (#858)
• Add prepare script to facilitate installing from git (#923)

1.41.3

• Prevent argument name clashes (#911)
• Fix UMD factory arguments (#918)
• Don't attempt to set computed values (#893)
• Fix TypeScript build error (#919)

1.41.2

• Handle attribute selectors with no value (#905)
• Retain async keyword when extracting functions (#904)
• Shallow clone data on initialisation (#891)

1.41.1

• Fix updates of destructured each blocks (#897)
• Don't warn on options.* event handler callee (#900)

1.41.0

• onwarn and onerror receive default handlers as second arguments (#883)
• Recognise muted as boolean property on <audio> elements (#886)
• Array destructuring for each block contexts (#889)

1.40.2

• Ignore @apply and similar in CSS (#871)
• Properly escape CSS in custom elements (#872)

1.40.1

• Always use explicit closing tags with innerHTML (#866)
• Escape text in textContent and innerHTML expressions (#868)

1.40.0

• Short fragment method names (#863)
• Extract declarations out of default export (#756)

1.39.4

• Extract shared init logic (#855)
• Allow console.* calls in event handlers (#782)
• Marker comments in output (#823)
• Use textContent and innerHTML where appropriate (#23)
• Various improvements to generated code

1.39.3

• Allow slot='...' inside custom elements (#827)
• Disallow slot='...' inside if/each blocks (#849)
• Use correct parent node for slotted if blocks (#850)

1.39.2

• Escape CSS in shadow DOM (#840)
• Fix missing anchor bug inside SVG elements (#843)

1.39.1

• Always use anchors for slotted content (#822)
• Prevent ES6 in helpers (#838)
• Correctly determine whether to use timeRangesToArray (#837)

1.39.0

• Always attach fragment to shadow root (#821)
• Add buffered, seekable, played bindings to media elements (#819)
• Quote class properties in legacy mode (#830)
• Warn on missing lang attribute on <html> (#828)

1.38.0

• Compile-time a11y warnings (#815)
• Remove redundant input blowback guards (#645)
• Use component name in debugging messages (#781)

1.37.0

• Experimental support for compiling to custom elements (#797)

1.36.0

• Optimize style attributes where possible (#455)

1.35.0

• set and get continue to work until destroy is complete (#788)
• Observers of unchanged bound values don't fire incorrectly (#804)
• Nested components with slotted content render correctly in SSR mode (#801)
• More efficient rendering of raw and slotted content (#637)
• Handle unquoted attributes in attribute selectors (#798)

1.34.0

• Support nested <slot> elements (#790)
• Attach options to instance (#550, #777)
• Error if transitions are applied to component (#791)
• Handle CSS variables in <style> tag (#757)

1.33.0

• Replace {{yield}} with <slot> — adds fallback content named slots, and options.slots (#763)

1.32.0

• Allow anchor initialisation option, alongside target (#784)
• Remove leading CSS selectors safely (#783)

1.31.0

• Add legacy compile option, which adds IE9 compatibility (#773)

1.30.0

• Update all component bindings simultaneously (#760)
• Fix @keyframes atrules with from and to selectors (#774)

1.29.3

• Only recompute tag and attribute values if they could have changed (#768)
• Fix CSS scoping with multiple levels of descendant selectors (#767)

1.29.2

• Preserve space before non-parenthesized media query expression (#759)
• Call create() on new iterations of static each blocks (#762)
• Use change events as well as input events to bind range inputs (#740)

1.29.1

• Replace set and destroy with noop when component is destroyed (#744)

1.29.0

• Add static setup method (#578)
• Hoist if block selectors (#751)
• More sigil escaping fixes (#750)

1.28.1

• Fix unescaping of special words in SSR mode (#741)

1.28.0

• Support ref:foo as a CSS selector (#693)
• Prevent magic-string bugs by only minifying CSS combinators if cascade: false (#743)
• Don't throw an error if component is destroyed twice (#643)

1.27.0

• Minify CSS and remove unused styles (#697)
• Optimize ternary expressions when excluding unused CSS (#696)
• Clear refs after ondestroy callbacks fire (#706)
• Prevent certain forms of component binding blowback (#721)
• Use helper to encapsulate styles (#375)
• Event propagation shorthand — on:foo equals on:foo='fire("foo", event) (#638)
• Allow refs.* in event handlers, and validate them (#686)

1.26.2

• Unescape # characters (#722)

1.26.1

• Fix select binding regression (#724)

1.26.0

• Enforce correct order of operations when initialising (#708 and #714)
• Ensure data is up-to-date when re-rendering yield block (#711)
• Fix unescaping of strings, preserve at-rules in CSS (#712)
• Preserve whitespace at end of each blocks (#713)

1.25.1

• Better CSS sourcemaps (#716)

1.25.0

• Fix hoisted event handlers (#699)
• Fire intro.start and outro.start events (#702)
• Preserve order of components in keyed each blocks (#700)
• Add cssMap property to compiler output (#698)

1.24.0

• Deconflict names with imports in SSR compiler (#655)
• Improved transition performance (#670)
• Run transitions on initial render (#651)
• Add dev mode warning if hydrate is true but hydratable was false (#664)
• Manipulate sourcemap to make missing loop values obvious (#683)
• Only add CSS scoping attributes where necessary (#679)
• Warn on unused CSS selectors (#678)
• Fix <select> binding in loop (#685)
• Prevent bindings from calling oncreate functions prematurely (#694)
• Simpler codegen (#673)

1.23.4

• Don't recreate if blocks incorrectly (#669)

1.23.3

• Pass parameters to get_block (#667)

1.23.2

• Fix if blocks being recreated on update (#665)

1.23.1

• Fix each-else blocks that are empty on initial render (#662)

1.23.0

• Hydration (#649)
• Correctly transform CSS selectors with pseudo-elements (#658)

1.22.5

• Fix nested component unmounting bug (#643)

1.22.4

• Include ast in svelte.compile return value (#632)
• Set initial value of <select> binding, if unspecified (#639)
• Mark indirect dependencies of <select> bindings (i.e. the dependencies of their <option> values) (#639)

1.22.3

• Fix nested component unmounting bug (#625)
• Allow components to have computed member expression bindings (#624)
• Handle empty <style> tags (#634)
• Warn on missing component (#623)
• Allow dynamic type attribute for unbound inputs (#620)
• Rename addEventListener and removeEventListener directives (#621)

1.22.2

• Escape template strings correctly in SSR output (#616)
• Prevent magic-string deprecation warning (#617)

1.22.1

• Sanitise event handler names (#612)

1.22.0

• Symmetry between mount and unmount. This is potentially a breaking change if your components import other components that were precompiled with an earlier version of Svelte (#592)
• Add cascade option, which prevents styles affecting child components if false, unless selectors are wrapped in :global(...) and keyframe declaration IDs are prefixed with -global-. This will become the default behaviour in v2 (#583)
• Support binding to computed member expressions (#602)
• Coerce empty string in number/range inputs to undefined, not 0 (#584)
• Fix insert location of DOM elements in each/if/nested component edge cases (#610)

1.21.0

• Always use helpers if referenced, not just for call expressions (#575)
• Fix parsing of <textarea> children (#599)
• Treat <textarea> value attributes and children as equivalent, and fail validation if both are present (#599)
• Fix <textarea> SSR (#599)
• Apply CSS transition styles immediately if transition has delay (#574)
• Ensure transitionManager is treeshakeable (#593)
• Fix for environments where node.style.animation is undefined (#587)
• Fix order of operations when dealing with <select> elements (#590)
• Downgrade 'invalid callee' to a warning (#579)
• Convert to TypeScript (#573)

1.20.2

• Fix destruction of compound if-blocks with outros (#572)

1.20.1

• Fix insertion order of if blocks and their anchors (#569)

1.20.0

• Faster, better updates of keyed each blocks (#373, #543)
• Use element IDs to robustly track dynamically injected <style> tags (#554)
• Abort outros before corresponding intros (#546)
• Generate less code for if blocks with else blocks (#540)
• Ensure {{yield}} block content is injected into the right place (#561)
• Simpler, more readable codegen code (#559)
• Validate transition directives (#564)
• Apply delays to bidirectional transitions (#562)
• Handle all valid HTML entities (#565)
• Fix outros on compound if blocks (#565)
• Validation for <:Window> tags (#565)
• Increased test coverage (#565)

1.19.1

• Export generateKeyframes, so that CSS transitions work

1.19.0

• Experimental support for transitions (#7)
• Use querySelector(':checked') instead of selectedOptions (#539)
• Stringify helpers before bundling them, to avoid renaming errors (#538)

1.18.2

• Parenthesize if-block conditions (#532)
• Fix parsing of parenthesized expressions (#534)
• Fix error on bind:checked that doesn't belong to a checkbox input (#529)

1.18.1

• Allow destroy() in event handlers (#523)
• Fix bug with {{yield}} blocks following elements (#524)

1.18.0

• Visit <select> attributes after children, to ensure options are in the right state (#521)
• Use sibling elements as anchors rather than creating comment nodes wherever possible (#3)

1.17.2

• Replace bad characters when creating variable names based on element names (#516)

1.17.1

• Fixes for static each-else and yield blocks (#509), (#514)
• Code generation tweaks (#504), (#507)

1.17.0

• Add currentTime, duration and paused bindings for media elements (#406)
• Don't treat helpers as dependencies (#492)
• Allow <:Window> event handlers to access component state (#497)
• Allow two-way binding to properties named 'component' (#495)
• Group checkbox bindings correctly, to avoid erroneously unchecking siblings (#498)
• Validate two-way bindings (#494)
• Allow dynamic each-block to have static else-block (#501)
• Initialise <select> value correctly (#502)

1.16.0

• Better code generation (#489), (#490), (#491)
• Prevent binding blowback on initial render (#488)

1.15.1

• Clone data before merging it with state (#479)
• Apply binding event handlers before user event handlers (#486)

1.15.0

• Dev mode — downgrade 'missing data' to a warning, and ignore whitelisted globals (#475)
• Fix <select> value binding when options are updated late (#476)
• Throw at compile time if event handler references invalid callee (#473)
• Check for helper function purity (#473)
• Validate namespace option (#473)

1.14.1

• Replace bad characters when creating variable names based on attributes (#470)

1.14.0

• Better guard against naming conflicts (#465)
• Better error if getters and setters are used with methods (#425)
• Don't create whitespace nodes inside elements that can't use them (#189)
• Collapse consecutive if statements with the same condition (#450)
• Window scroll bindings are bidirectional (#404)
• Add bind:online to window (#404)
• In dev mode, throw if read-only properties are set (#404)
• Prevent conflicts with component name (#464)
• Ensure event handler names are deconflicted (#466)

1.13.7

• Fix observers — defer: true now triggers callback after DOM is updated (#441)
• Handle empty computed property (#452)
• Correctly bind one-way <select> value attributes with objects (#423)
• Hoist event handlers inside each blocks, where possible (#456)
• Don't bind event handler callbacks (#433)
• Internal refactoring and neater code generation (#453)

1.13.6

• Use assign helper instead of Object.assign for better performance and legacy compatibility (#431)
• Improved code generation (#419), (#440), (#442)

1.13.5

• Read range and number input values as numbers (#436)
• Better error for bind:value='{{foo}}' (#437)

1.13.4

• Prevent unclosed <script> tag causing infinite loop (#435)

1.13.3

• Correctly handle {{true}}, {{false}} and {{null}} (#424)
• Update <select> value attributes correctly (#423)
• Bind custom event handler callbacks (#428)
• Disallow import root (#430)
• Prevent component bindings mutating the wrong object (#432)

1.13.2

• Fix deep component bindings (#420)
• Include css property in compiler output (#409)
• Treat functions as mutable objects when recomputing (#413
• Include magic-string in bundle (#410)
• Disable unneeded Bublé transformations for slimmer output (#411)

1.13.1

• Prevent infinite loops with pathological component bindings (#398)
• More robust deconflicting (#401)

1.13.0

• Add <:Window> meta tag with event listeners, and a handful of bindings (#371)
• Don't uncheck radios incorrectly (#399)

1.12.1

• Deconflict non-helper functions (addCss etc) (#388)
• Allow reserved words in tags, e.g. {{class}} (#383)

1.12.0

• Shorthand attributes — <Widget :foo/> is equivalent to <Widget foo='{{foo}}'/> (#384)
• Support bind:group for radio and checkbox inputs (#311, #312)
• Better sourcemap support for two-way bindings

1.11.4

• Dev mode warning for bad component.observe arguments (#369)
• Translate component.on('teardown', ...) to component.on('destroy', ...) and add dev warning (#365)
• Use shared prototype to save bytes (#378)

1.11.3

• Undo CSS behaviour change in 1.11.2 (#372)
• Pin version of css-tree (#370)

1.11.2

• Add component CSS to each document a component is rendered to (#331)

1.11.1

• Fix two-way binding for components inside each blocks (#356)

1.11.0

• Add format: 'eval' and svelte.create, to create components directly from source code (#345)
• Node 4 compatibility (#109)

1.10.3

• Prevent '</script>' string occurrence breaking pages (#349)
• Allow reference to whitelisted globals without properties (#333)
• Don't remove   incorrectly (#348)
• let -> var in addCss block (#351)

1.10.2

• Accept any case for doctype declarations (#336)
• Allow non-top-level <script> and <style> tags to pass through without processing (#335)

1.10.1

• typecheck argument in _set when in dev mode (#342)
• Prevent duplicate helpers in non-shared mode (#337)

1.10.0

• Component self-references with <:Self/> (#51)
• Two-way binding with <select multiple> (#313)

1.9.1

• Better error for malformed event handlers (#220)
• Allow function expressions in tags (#269)

1.9.0

• Add development warnings (#13), (#320), (#177), (#249)
• Better error if parser encounters an unmatched closing tag (#321)

1.8.1

• Allow implicitly closed elements (#318)
• More informative error messages for unclosed elements/blocks (#258)
• Deprecate onrender and onteardown in favour of oncreate and ondestroy (#40)

1.8.0

• Prevent duplicate imports (#308)
• Use input events (not change) for all input elements other than checkbox and radio, and textareas (#309)
• Encapsulate keyframe declarations (#245)

1.7.1

• Deconflict imports and shared helpers (#222)
• Deconflict each-block contexts and reserved words (#222)
• Allow shorthand properties in expressions (#296)

1.7.0

• Include CSS AST in svelte.parse output (#302)
• Better handling of CSS parse errors (#302)
• Initialise <select> elements with two-way binding correctly (#301)
• Allow local context in component event handlers inside each blocks (#290)
• Fix two-way binding for components inside each blocks (#290)

1.6.11

• Initialise dynamic <option> value correctly (#291)

1.6.10

• Ensure sources and sourcesContent are populated in sourcemaps, even if none of the original code is used (#295)
• Add outputFilename option to populate file and sources sourcemap properties correctly (#295)

1.6.9

• Don't trigger bindings for torn-down components (#277)
• SSR: Handle two-way bindings (#275)
• Improve performance by checking data has changed before updates (#279)
• Parse CSS with css-tree to prevent transformation errors with unconventional styles (#288)

1.6.8

• Always trigger onrender, including when change initiator is a nested component (#263)
• Handle default function parameters in computations (#274)

1.6.7

• SSR: Fix apostrophes (#267)
• Add xmlns attributes to SVGs (#262)

1.6.6

• Omit text from comment anchors (#247)
• Handle xlink attributes (#264)

1.6.5

• Handle <!doctype> declarations (#255)

1.6.4

• Fix updates of yields inside each blocks (20e1b05)
• SSR: Handle attributes with values that begin with a number (#248)
• Handle multiline comments in CSS (#252)

1.6.3

• Fix {{yield}} bugs for components inside if and each blocks (#230, #231)
• Set attributes on <svg> elements correctly (#233)
• Add svelte.VERSION property to compiler

1.6.2

• Use helpers for addEventListener, removeEventListener, setAttribute (#227)
• Escape sharedPath (#229)
• Handle attributes with values that begin with a number (#234)
• Update dependencies

1.6.1

• SSR: Handle component directives at arbitrary positions (#221)
• Provide useful feedback on invalid void closing tag (#224)

1.6.0

• Replace standalone: false with shared: true, or shared: 'custom/path/to/shared.js' (#218)
• Include shared.js in package

1.5.0

• Implement standalone: false (#9)
• SSR: Handle component directives (216)

1.4.0

• Keyed each blocks (#81)

1.3.1

• Remove file extensions from AMD dependencies (#144)
• Throw if options.name is illegal (#102)

1.3.0

• SSR compiler: Support format option (#196)
• SSR compiler: Don't self-close 'normal' elements (#200)
• Remove leading spaces from scoped CSS (#140)
• Internal refactoring

1.2.5

• Allow whitelisted globals in templates (#185)
• Intercept parse errors with options.onerror

1.2.4

• SSR compiler: Implement {{{triples}}} (#197)
• SSR compiler: Escape HTML in tags (#197)

1.2.3

• Add support for namespace declaration for SVG (etc) components (#147)
• Throw error if methods or lifecycle hooks are arrow functions that use this or arguments (#179)
• Use setAttribute() for list attributes, to preserve link to <datalist> (#178)
• Throw error if default export is not an object literal (#190)
• Internal refactoring

1.2.2

• Omit directives in server-side rendering (#163)
• Handle comments in SSR (#165)
• Support calling methods of event/this in event handlers (#162)
• Remove mount from public API (#150)

1.2.1

• Server-side rendering is available as a compiler option (generate: 'ssr') (#159)
• Allow call expressions where function is not in helpers (#163)

1.2.0

• Server-side rendering of HTML (#148) and CSS (#154)

1.1.3

• Handle xmlns attributes correctly (#142)
• Error on duplicate <style>/<script> tags rather than failing silently (#142)
• Don't create whitespace text nodes inside SVG elements (#142)
• Require void elements to be lowercase, to eliminate confusion with components (#137)

1.1.2

• Deconflict variable names (#88, #126)

1.1.1

• Support multiple SVG elements in a component (#130)

1.1.0

• Separate fragment creation from mount (#91)
• Trigger onrender hook at correct time for nested components (#103)
• Fix keypath dynamic attributes in components (#46)
• Implement {{yield}} (#112)
• Optimise teardown (#99)
• Require computed properties to have at least one dependency (#115)
• Support {{#each ...}}...{{else}}...{{/each}} (#90)
• Triple mustaches (#35)

1.0.7

• Correctly escape HTML entities (#85)

1.0.6

• Generate useful sourcemaps (#60)

1.0.5

• Ensure compiler only generates ES5 code (#75)
• get() without arguments returns entire state object (#73)

1.0.4

• Handle empty attributes in elements and components (#63)
• Detach top-level text nodes inside departing each blocks (#62)

1.0.3

• Better generated code for if blocks, especially with else/elseif chains (#28)
• Trim unnecessary whitespace from else/elseif blocks (#49)
• Handle trailing comments in script tags (#64)

1.0.2

Set style.cssText rather than style (#44)

1.0.1

• Preserve SVG namespace inside each blocks
• Always use setAttribute with SVG elements

1.0.0

• Generate AMD, CJS, IIFE and UMD builds
• Correctly insert text nodes before anchors (#31)

0.3.0

• Fix bug where departing element would unset ref incorrectly (#24)
• Basic template validation (#6)
• Fire onrender hooks once component is in DOM (#18)
• Only detach nodes when necessary to do so (#26)

0.2.2

• On second thoughts, don't transpile build. Was only really for Uglify's benefit, which is daft

0.2.1

• Transpile build

0.2.0

• Only generate UMD build, for now
• Include dependencies in the build, treat as devDependencies
• Faster initial render
• Parent data overrides child defaults
• Remove top-level text nodes on teardown
• Handle readUntil errors in parser
• Basic <select> binding
• Handle missing data
• Prevent infinite set/observe loops
• Add bind:foo shorthand
• else and elseif blocks
• Hoist imports

0.1.1

• Support unquoted attributes
• Handle entities in attributes
• Inline nested components
• fire and on methods

0.1.0

• Breaking change – Svelte compiler now generates constructor functions rather than factories (#2)
• SVG support

0.0.2

• First release capable of building TodoMVC

0.0.1

• Just squatting on the package name