---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
- breaking: Minimum supported Node version is now Node 16 ([#8566](https://github.com/sveltejs/svelte/pull/8566))
- breaking: Minimum supported webpack version is now webpack 5 ([#8515](https://github.com/sveltejs/svelte/pull/8515))
- breaking: Bundlers must specify the `browser` condition when building a frontend bundle for the browser ([#8516](https://github.com/sveltejs/svelte/pull/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]
(https://github.com/sveltejs/svelte/pull/8516))
- breaking: Minimum supported `rollup-plugin-svelte` version is now 7.1.5 ([198dbcf](https://github.com/sveltejs/svelte/commit/198dbcf))
- breaking: Minimum supported `svelte-loader` is now 3.1.8 ([198dbcf](https://github.com/sveltejs/svelte/commit/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]
(https://github.com/sveltejs/svelte/pull/8488))
- breaking: Remove `svelte/register` hook, CJS runtime version and CJS compiler output ([#8613](https://github.com/sveltejs/svelte/pull/8613))
- breaking: Stricter types for `createEventDispatcher` (see PR for migration instructions) ([#7224](https://github.com/sveltejs/svelte/pull/7224))
- breaking: Stricter types for `Action` and `ActionReturn` (see PR for migration instructions) ([#7442](https://github.com/sveltejs/svelte/pull/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](https://github.com/sveltejs/svelte/pull/8136))
- breaking: Overhaul and drastically improve creating custom elements with Svelte (see PR for list of changes and migration instructions) ([#8457](https://github.
com/sveltejs/svelte/pull/8457))
- breaking: Deprecate `SvelteComponentTyped` in favor of `SvelteComponent` ([#8512](https://github.com/sveltejs/svelte/pull/8512))
- breaking: Make transitions local by default to prevent confusion around page navigations ([#6686](https://github.com/sveltejs/svelte/issues/6686))
- breaking: Error on falsy values instead of stores passed to `derived` ([#7947](https://github.com/sveltejs/svelte/pull/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](https://github.com/sveltejs/svelte/pull/6049))
- breaking: Change order in which preprocessors are applied ([#8618](https://github.com/sveltejs/svelte/pull/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 ([#8627](https://github.com/sveltejs/svelte/pull/8627))
- breaking: use `CustomEvent` constructor instead of deprecated `createEvent` method ([#8775](https://github.com/sveltejs/svelte/pull/8775))
### Minor Changes
- Add a way to modify attributes for script/style preprocessors ([#8618](https://github.com/sveltejs/svelte/pull/8618))
- Improve hydration speed by adding `data-svelte-h` attribute to detect unchanged HTML elements ([#7426](https://github.com/sveltejs/svelte/pull/7426))
- Allow `#each` to iterate over iterables like `Set`, `Map` etc ([#7425](https://github.com/sveltejs/svelte/issues/7425))
- Improve duplicate key error for keyed `each` blocks ([#8411](https://github.com/sveltejs/svelte/pull/8411))
- Warn about `:` in attributes and props to prevent ambiguity with Svelte directives ([#6823](https://github.com/sveltejs/svelte/issues/6823))
- feat: add version info to `window`. You can opt out by setting `discloseVersion` to `false` in the compiler options ([#8761](https://github.com/sveltejs/svelte/pull/8761))
- feat: smaller minified output for destructor chunks ([#8763](https://github.com/sveltejs/svelte/pull/8763))
### Patch Changes
- Bind `null` option and input values consistently ([#8312](https://github.com/sveltejs/svelte/issues/8312))
- Allow `$store` to be used with changing values including nullish values ([#7555](https://github.com/sveltejs/svelte/issues/7555))
- Initialize stylesheet with `/* empty */` to enable setting CSP directive that also works in Safari ([#7800](https://github.com/sveltejs/svelte/pull/7800))
- Treat slots as if they don't exist when using CSS adjacent and general sibling combinators ([#8284](https://github.com/sveltejs/svelte/issues/8284))
- Fix transitions so that they don't require a `style-src 'unsafe-inline'` Content Security Policy (CSP) ([#6662](https://github.com/sveltejs/svelte/issues/6662)).