sveltejs/svelte svelte@4.0.0

on GitHub

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](https://github.
  com//pull/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](https://github.com/sveltejs/svelte/pull/
  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](https://github.com/sveltejs/svelte/
  pull/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)