2.4.0

* Improve performance of sl-icon by caching later

* Fixed error handling

* Don't use requestInclude in sl-icon

* Separate sl-icon errors into cacheable and retryable errors

.gitignore

@@ -3,6 +3,5 @@
 docs/dist
 docs/search.json
 dist
-examples
 node_modules
 src/react

cspell.json

@@ -9,9 +9,13 @@
     "atrule",
     "autocorrect",
     "autofix",
+    "autoload",
+    "autoloader",
+    "autoloading",
     "autoplay",
     "bezier",
     "boxicons",
+    "CACHEABLE",
     "callout",
     "callouts",
     "chatbubble",
@@ -27,6 +31,7 @@
     "Consolas",
     "contenteditable",
     "copydir",
+    "Cotte",
     "coverpage",
     "crossorigin",
     "crutchcorn",
@@ -35,6 +40,7 @@
     "datetime",
     "describedby",
     "Docsify",
+    "dogfood",
     "dropdowns",
     "easings",
     "enterkeyhint",
@@ -53,6 +59,7 @@
     "FOUC",
     "FOUCE",
     "fullscreen",
+    "gestern",
     "giga",
     "globby",
     "Grayscale",
@@ -70,10 +77,12 @@
     "jsonata",
     "keydown",
     "keyframes",
+    "Kool",
     "labelledby",
     "Laravel",
     "LaViska",
     "listbox",
+    "listitem",
     "litelement",
     "lowercasing",
     "Lucide",
@@ -103,12 +112,18 @@
     "reregister",
     "resizer",
     "resizers",
+    "retargeted",
+    "RETRYABLE",
     "rgba",
     "roadmap",
     "Roboto",
+    "roledescription",
+    "Sapan",
     "saturationl",
     "Schilp",
     "scrollbars",
+    "scrollend",
+    "scroller",
     "Segoe",
     "semibold",
     "slotchange",
@@ -121,6 +136,7 @@
     "tabpanel",
     "templating",
     "tera",
+    "testid",
     "textareas",
     "textfield",
     "tinycolor",
@@ -143,6 +159,7 @@
   "ignorePaths": [
     "package.json",
     "package-lock.json",
+    "docs/assets/examples/include.html",
     ".vscode/**",
     "src/translations/!(en).ts",
     "**/*.min.js"

docs/_sidebar.md

@@ -31,6 +31,8 @@
   - [Button](/components/button)
   - [Button Group](/components/button-group)
   - [Card](/components/card)
+  - [Carousel](/components/carousel)
+  - [Carousel Item](/components/carousel-item)
   - [Checkbox](/components/checkbox)
   - [Color Picker](/components/color-picker)
   - [Details](/components/details)

docs/assets/plugins/metadata/metadata.js

@@ -436,6 +436,9 @@
           result += `
             ## Importing
 
+            If you're using the autoloader or the traditional loader, you can ignore this section. Otherwise, feel free to
+            use any of the following snippets to [cherry pick](getting-started/installation#cherry-picking) this component.
+
             <sl-tab-group>
             <sl-tab slot="nav" panel="script">Script</sl-tab>
             <sl-tab slot="nav" panel="import">Import</sl-tab>

docs/assets/styles/docs.css

@@ -8,6 +8,17 @@ html {
   box-sizing: inherit;
 }
 
+/* Show custom elements only after they're registered */
+:not(:defined),
+:not(:defined) * {
+  opacity: 0;
+}
+
+:defined {
+  opacity: 1;
+  transition: 0.1s opacity;
+}
+
 body {
   font-family: var(--sl-font-sans);
   font-size: var(--sl-font-size-medium);

docs/components/carousel-item.md

@@ -0,0 +1,81 @@
+# Carousel Item
+
+[component-header:sl-carousel-item]
+
+```html preview
+<sl-carousel pagination>
+  <sl-carousel-item>
+    <img
+      alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
+      src="/assets/examples/carousel/mountains.jpg"
+    />
+  </sl-carousel-item>
+  <sl-carousel-item>
+    <img
+      alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
+      src="/assets/examples/carousel/waterfall.jpg"
+    />
+  </sl-carousel-item>
+  <sl-carousel-item>
+    <img
+      alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
+      src="/assets/examples/carousel/sunset.jpg"
+    />
+  </sl-carousel-item>
+  <sl-carousel-item>
+    <img
+      alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
+      src="/assets/examples/carousel/field.jpg"
+    />
+  </sl-carousel-item>
+  <sl-carousel-item>
+    <img
+      alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
+      src="/assets/examples/carousel/valley.jpg"
+    />
+  </sl-carousel-item>
+</sl-carousel>
+```
+
+```jsx react
+import { SlCarousel, SlCarouselItem } from '@shoelace-style/shoelace/dist/react';
+
+const App = () => (
+  <SlCarousel pagination>
+    <SlCarouselItem>
+      <img
+        alt="The sun shines on the mountains and trees - Photo by Adam Kool on Unsplash"
+        src="/assets/examples/carousel/mountains.jpg"
+      />
+    </SlCarouselItem>
+    <SlCarouselItem>
+      <img
+        alt="A waterfall in the middle of a forest - Photo by Thomas Kelly on Unsplash"
+        src="/assets/examples/carousel/waterfall.jpg"
+      />
+    </SlCarouselItem>
+    <SlCarouselItem>
+      <img
+        alt="The sun is setting over a lavender field - Photo by Leonard Cotte on Unsplash"
+        src="/assets/examples/carousel/sunset.jpg"
+      />
+    </SlCarouselItem>
+    <SlCarouselItem>
+      <img
+        alt="A field of grass with the sun setting in the background - Photo by Sapan Patel on Unsplash"
+        src="/assets/examples/carousel/field.jpg"
+      />
+    </SlCarouselItem>
+    <SlCarouselItem>
+      <img
+        alt="A scenic view of a mountain with clouds rolling in - Photo by V2osk on Unsplash"
+        src="/assets/examples/carousel/valley.jpg"
+      />
+    </SlCarouselItem>
+  </SlCarousel>
+);
+```
+
+?> Additional demonstrations can be found in the [carousel examples](/components/carousel).
+
+[component-metadata:sl-carousel-item]

docs/components/checkbox.md

@@ -100,7 +100,8 @@ Use the `setCustomValidity()` method to set a custom validation message. This wi
   const errorMessage = `Don't forget to check me!`;
 
   // Set initial validity as soon as the element is defined
-  customElements.whenDefined('sl-checkbox').then(() => {
+  customElements.whenDefined('sl-checkbox').then(async () => {
+    await checkbox.updateComplete;
     checkbox.setCustomValidity(errorMessage);
   });
 

docs/components/dropdown.md

@@ -64,7 +64,7 @@ const App = () => (
 
 ### Getting the Selected Item
 
-When dropdowns are used with [menus](/components/menu), you can listen for the `sl-select` event to determine which menu item was selected. The menu item element will be exposed in `event.detail.item`. You can set `value` props to make it easier to identify commands.
+When dropdowns are used with [menus](/components/menu), you can listen for the [`sl-select`](/components/menu#events) event to determine which menu item was selected. The menu item element will be exposed in `event.detail.item`. You can set `value` props to make it easier to identify commands.
 
 ```html preview
 <div class="dropdown-selection">

docs/components/icon.md

@@ -531,7 +531,7 @@ Icons in this library are licensed under the [Apache 2.0 License](https://github
 </div>
 ```
 
-## Tabler Icons
+### Tabler Icons
 
 This will register the [Tabler Icons](https://tabler-icons.io/) library using the jsDelivr CDN. This library features over 1,950 open source icons.
 

docs/components/qr-code.md

@@ -17,8 +17,10 @@ QR codes are useful for providing small pieces of information to users who can q
   const qrCode = container.querySelector('sl-qr-code');
   const input = container.querySelector('sl-input');
 
-  input.value = qrCode.value;
-  input.addEventListener('sl-input', () => (qrCode.value = input.value));
+  customElements.whenDefined('sl-qr-code').then(() => {
+    input.value = qrCode.value;
+    input.addEventListener('sl-input', () => (qrCode.value = input.value));
+  });
 </script>
 
 <style>

docs/components/radio-group.md

@@ -175,7 +175,7 @@ Use the `setCustomValidity()` method to set a custom validation message. This wi
   const errorMessage = 'You must choose the last option';
 
   // Set initial validity as soon as the element is defined
-  customElements.whenDefined('sl-radio-group').then(() => {
+  customElements.whenDefined('sl-radio').then(() => {
     radioGroup.setCustomValidity(errorMessage);
   });
 

docs/frameworks/angular.md

@@ -41,6 +41,38 @@ import { AppComponent } from './app.component';
 export class AppModule {}
 ```
 
+## Reference Shoelace components in your Angular component code
+
+```js
+import { SlDrawer } from '@shoelace-style/shoelace';
+
+@Component({
+  selector: 'app-drawer-example',
+  template: '<div id="page"><button (click)="showDrawer()">Show drawer</button><sl-drawer #drawer label="Drawer" class="drawer-focus" style="--size: 50vw"><p>Drawer content</p></sl-drawer></div>'
+})
+export class DrawerExampleComponent implements OnInit {
+
+  // use @ViewChild to get a reference to the #drawer element within component template
+  @ViewChild('drawer')
+  drawer?: ElementRef<SlDrawer>;
+
+  ...
+
+  constructor(...) {
+  }
+
+  ngOnInit() {
+  }
+
+  ...
+
+  showDrawer() {
+    // use nativeElement to access Shoelace components
+    this.drawer?.nativeElement.show();
+  }
+}
+```
+
 Now you can start using Shoelace components in your app!
 
 ?> Are you using Shoelace with Angular? [Help us improve this page!](https://github.com/shoelace-style/shoelace/blob/next/docs/frameworks/angular.md)

docs/frameworks/vue.md

@@ -58,7 +58,7 @@ Now you can start using Shoelace components in your app!
 
 ### QR code generator example
 
-```vue
+```html
 <template>
   <div class="container">
     <h1>QR code generator</h1>
@@ -70,22 +70,22 @@ Now you can start using Shoelace components in your app!
 </template>
 
 <script setup>
-import { ref } from 'vue';
-import '@shoelace-style/shoelace/dist/components/qr-code/qr-code.js';
-import '@shoelace-style/shoelace/dist/components/input/input.js';
+  import { ref } from 'vue';
+  import '@shoelace-style/shoelace/dist/components/qr-code/qr-code.js';
+  import '@shoelace-style/shoelace/dist/components/input/input.js';
 
-const qrCode = ref();
+  const qrCode = ref();
 </script>
 
 <style>
-.container {
-  max-width: 400px;
-  margin: 0 auto;
-}
+  .container {
+    max-width: 400px;
+    margin: 0 auto;
+  }
 
-sl-input {
-  margin: var(--sl-spacing-large) 0;
-}
+  sl-input {
+    margin: var(--sl-spacing-large) 0;
+  }
 </style>
 ```
 
@@ -98,3 +98,18 @@ When binding complex data such as objects and arrays, use the `.prop` modifier t
 ```
 
 ?> Are you using Shoelace with Vue? [Help us improve this page!](https://github.com/shoelace-style/shoelace/blob/next/docs/frameworks/vue.md)
+
+### Slots
+
+To use Shoelace components with slots, follow the Vue documentation on using [slots with custom elements](https://vuejs.org/guide/extras/web-components.html#building-custom-elements-with-vue).
+
+Here is an example:
+
+```html
+<sl-drawer label="Drawer" placement="start" class="drawer-placement-start" :open="drawerIsOpen">
+  This drawer slides in from the start.
+  <div slot="footer">
+    <sl-button variant="primary" @click=" drawerIsOpen = false">Close</sl-button>
+  </div>
+</sl-drawer>
+```

docs/getting-started/installation.md

@@ -1,32 +1,50 @@
 # Installation
 
-You can use Shoelace via CDN or by installing it locally. You can also [cherry pick](#cherry-picking) individual components for faster load times.
-
-If you're using a framework, make sure to check out the pages for [React](/frameworks/react), [Vue](/frameworks/vue), and [Angular](/frameworks/angular).
+You can load Shoelace via CDN or by installing it locally. If you're using a framework, make sure to check out the pages for [React](/frameworks/react), [Vue](/frameworks/vue), and [Angular](/frameworks/angular) for additional information.
 
 ## CDN Installation (Easiest)
 
-The easiest way to install Shoelace is with the CDN. Just add the following tags to your page to get all components and the default light theme.
+<sl-tab-group>
+<sl-tab slot="nav" panel="autoloader" active>Autoloader</sl-tab>
+<sl-tab slot="nav" panel="traditional">Traditional Loader</sl-tab>
+
+<sl-tab-panel name="autoloader">
+
+The experimental autoloader is the easiest and most efficient way to use Shoelace. A lightweight script watches the DOM for unregistered Shoelace elements and lazy loads them for you — even if they're added dynamically.
+
+While convenient, autoloading may lead to a [Flash of Undefined Custom Elements](https://www.abeautifulsite.net/posts/flash-of-undefined-custom-elements/). The linked article describes some ways to alleviate it.
+
+<!-- prettier-ignore -->
+```html
+<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/themes/light.css" />
+<script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace-autoloader.js"></script>
+```
+
+</sl-tab-panel>
+
+<sl-tab-panel name="traditional">
+
+The traditional CDN loader registers all Shoelace elements up front. Note that, if you're only using a handful of components, it will be much more efficient to stick with the autoloader. However, you can also [cherry pick](#cherry-picking) components if you want to load specific ones up front.
 
 ```html
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/themes/light.css" />
 <script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace.js"></script>
 ```
 
-?> If you're only using a handful of components, it will be more efficient to [cherry pick](#cherry-picking) the ones you need.
+</sl-tab-panel>
+</sl-tab-group>
 
 ### Dark Theme
 
-If you prefer to use the [dark theme](/getting-started/themes#dark-theme) instead, use this code and add `<html class="sl-theme-dark">` to the page.
+The code above will load the light theme. If you want to use the [dark theme](/getting-started/themes#dark-theme) instead, update the stylesheet as shown below and add `<html class="sl-theme-dark">` to your page.
 
 ```html
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/themes/dark.css" />
-<script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace.js"></script>
 ```
 
 ### Light & Dark Theme
 
-If you want to load the light or dark theme based on the user's `prefers-color-scheme` setting, use this. The `media` attributes ensure that only the user's preferred theme stylesheet loads and the `onload` attribute sets the appropriate [theme class](/getting-started/themes) on the `<html>` element.
+If you want to load the light or dark theme based on the user's `prefers-color-scheme` setting, use the stylesheets below. The `media` attributes ensure that only the user's preferred theme stylesheet loads and the `onload` attribute sets the appropriate [theme class](/getting-started/themes) on the `<html>` element.
 
 ```html
 <link
@@ -40,7 +58,6 @@ If you want to load the light or dark theme based on the user's `prefers-color-s
   href="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/themes/dark.css"
   onload="document.documentElement.classList.add('sl-theme-dark');"
 />
-<script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace.js"></script>
 ```
 
 Now you can [start using Shoelace!](/getting-started/usage)
@@ -68,7 +85,7 @@ Alternatively, [you can use a bundler](#bundling).
 
 ## Setting the Base Path
 
-Some components rely on assets (icons, images, etc.) and Shoelace needs to know where they're located. For convenience, Shoelace will try to auto-detect the correct location based on the script you've loaded it from. This assumes assets are colocated with `shoelace.js` and will "just work" for most users.
+Some components rely on assets (icons, images, etc.) and Shoelace needs to know where they're located. For convenience, Shoelace will try to auto-detect the correct location based on the script you've loaded it from. This assumes assets are colocated with `shoelace.js` or `shoelace-autoloader.js` and will "just work" for most users.
 
 However, if you're [cherry picking](#cherry-picking) or [bundling](#bundling) Shoelace, you'll need to set the base path. You can do this one of two ways.
 
@@ -88,9 +105,7 @@ However, if you're [cherry picking](#cherry-picking) or [bundling](#bundling) Sh
 
 ## Cherry Picking
 
-The previous approach is the _easiest_ way to load Shoelace, but easy isn't always efficient. You'll incur the full size of the library even if you only use a handful of components. This is convenient for prototyping or if you're using most of the components, but it may result in longer load times in production. To improve this, you can cherry pick the components you need.
-
-Cherry picking can be done from your local install or [directly from the CDN](https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/). This will limit the number of files the browser has to download and reduce the amount of bytes being transferred. The disadvantage is that you need to load components manually.
+Cherry picking can be done from [the CDN](#cdn-installation-easiest) or your [local installation](#local-installation). This approach will load only the components you need up front, while limiting the number of files the browser has to download. The disadvantage is that you need to import each individual component.
 
 Here's an example that loads only the button component. Again, if you're not using a module resolver, you'll need to adjust the path to point to the folder Shoelace is in.
 

docs/getting-started/overview.md

@@ -32,9 +32,10 @@ Designed in New Hampshire by [Cory LaViska](https://twitter.com/claviska).
 
 Add the following code to your page.
 
+<!-- prettier-ignore -->
 ```html
 <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/themes/light.css" />
-<script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace.js"></script>
+<script type="module" src="https://cdn.jsdelivr.net/npm/@shoelace-style/shoelace@%VERSION%/dist/shoelace-autoloader.js"></script>
 ```
 
 Now you have access to all of Shoelace's components! Try adding a button:
@@ -43,7 +44,7 @@ Now you have access to all of Shoelace's components! Try adding a button:
 <sl-button>Click me</sl-button>
 ```
 
-?> This will load all of Shoelace's components, but you should probably only load the ones you're actually using. To learn how, or for other ways to install Shoelace, refer to the [installation instructions](getting-started/installation).
+?> This will activate Shoelace's experimental autoloader, which registers components on the fly as you use them. To learn more about it, or for other ways to install Shoelace, refer to the [installation instructions](getting-started/installation).
 
 ## New to Web Components?
 

docs/getting-started/usage.md

@@ -33,7 +33,9 @@ Refer to a component's documentation for a complete list of its properties.
 
 ## Events
 
-You can listen for standard events such as `click`, `mouseover`, etc. as you normally would. In addition, some components emit custom events. These work the same way as standard events, but are prefixed with `sl-` to prevent collisions with standard events and other libraries.
+You can listen for standard events such as `click`, `mouseover`, etc. as you normally would. However, it's important to note that many events emitted within a component's shadow root will be [retargeted](https://dom.spec.whatwg.org/#retarget) to the host element. This may result in, for example, multiple `click` handlers executing even if the user clicks just once. Furthermore, `event.target` will point to the host element, making things even more confusing.
+
+As a result, you should almost always listen for custom events instead. For example, instead of listening to `click` to determine when an `<sl-checkbox>` gets toggled, listen to `sl-change`.
 
 ```html
 <sl-checkbox>Check me</sl-checkbox>
@@ -46,7 +48,7 @@ You can listen for standard events such as `click`, `mouseover`, etc. as you nor
 </script>
 ```
 
-Refer to a component's documentation for a complete list of its custom events.
+All custom events are prefixed with `sl-` to prevent collisions with standard events and other libraries. Refer to a component's documentation for a complete list of its custom events.
 
 ## Methods
 
@@ -164,7 +166,7 @@ checkbox.checked = true;
 console.log(checkbox.hasAttribute('checked')); // false
 ```
 
-Most devs will expect this to be `true` instead of `false`, but the component hasn't had a chance to re-render yet so the attribute doesn't exist when `hasAttribute()` is called. Since changes are batched, we need to wait for the update before proceeding. This can be done using the `updateComplete` property, which is available on all Lit-based components.
+Most developers will expect this to be `true` instead of `false`, but the component hasn't had a chance to re-render yet so the attribute doesn't exist when `hasAttribute()` is called. Since changes are batched, we need to wait for the update before proceeding. This can be done using the `updateComplete` property, which is available on all Lit-based components.
 
 ```js
 const checkbox = document.querySelector('sl-checkbox');

docs/index.html

@@ -39,9 +39,9 @@
     <!-- Import Shoelace -->
     <link rel="stylesheet" href="/dist/themes/light.css" />
     <link rel="stylesheet" href="/dist/themes/dark.css" />
-    <script type="module" src="/dist/shoelace.js"></script>
+    <script type="module" src="/dist/shoelace-autoloader.js"></script>
   </head>
-  <body data-shoelace="/dist">
+  <body>
     <div id="app"></div>
     <script>
       // Set the initial theme to prevent flashing

docs/resources/changelog.md

@@ -6,6 +6,59 @@ Components with the <sl-badge variant="warning" pill>Experimental</sl-badge> bad
 
 New versions of Shoelace are released as-needed and generally occur when a critical mass of changes have accumulated. At any time, you can see what's coming in the next release by visiting [next.shoelace.style](https://next.shoelace.style).
 
+## 2.4.0
+
+- Added the `discover()` function to the experimental autoloader's exports [#1236](https://github.com/shoelace-style/shoelace/pull/1236)
+- Added the `size` attribute to `<sl-radio-group>` so labels and controls will be sized consistently [#1301](https://github.com/shoelace-style/shoelace/issues/1301)
+- Added tests for `<sl-animated-image>` [#1246](https://github.com/shoelace-style/shoelace/pull/1246)
+- Added tests for `<sl-animation>` [#1274](https://github.com/shoelace-style/shoelace/pull/1274)
+- Fixed a bug in `<sl-tree-item>` that prevented long labels from wrapping [#1243](https://github.com/shoelace-style/shoelace/issues/1243)
+- Fixed a bug in `<sl-tree-item>` that caused labels to be misaligned when text wraps [#1244](https://github.com/shoelace-style/shoelace/issues/1244)
+- Fixed an incorrect CSS property value in `<sl-checkbox>` [#1272](https://github.com/shoelace-style/shoelace/pull/1272)
+- Fixed a bug in `<sl-avatar>` that caused the initials to show up behind images with transparency [#1260](https://github.com/shoelace-style/shoelace/pull/1260)
+- Fixed a bug in `<sl-split-panel>` that prevented the divider from being focusable in some browsers [#1288](https://github.com/shoelace-style/shoelace/issues/1288)
+- Fixed a bug that caused `<sl-tab-group>` to affect scrolling when initializing [#1292](https://github.com/shoelace-style/shoelace/issues/1292)
+- Fixed a bug in `<sl-menu-item>` that allowed the hover state to show when focused [#1282](https://github.com/shoelace-style/shoelace/issues/1282)
+- Fixed a bug in `<sl-carousel>` that prevented interactive elements from receiving clicks [#1262](https://github.com/shoelace-style/shoelace/issues/1262)
+- Fixed a bug in `<sl-input>` that caused `valueAsDate` and `valueAsNumber` to not be set synchronously in some cases [#1302](https://github.com/shoelace-style/shoelace/issues/1302)
+- Improved the behavior of `<sl-carousel>` when used inside a flex container [#1235](https://github.com/shoelace-style/shoelace/pull/1235)
+- Improved the behavior of `<sl-tree-item>` to support buttons and other interactive elements [#1234](https://github.com/shoelace-style/shoelace/issues/1234)
+- Improved the performance of `<sl-include>` to prevent an apparent memory leak in some browsers [#1284](https://github.com/shoelace-style/shoelace/pull/1284)
+- Improved the accessibility of `<sl-select>`, `<sl-split-panel>`, and `<sl-details>` by ensuring slots don't have roles [#1287](https://github.com/shoelace-style/shoelace/issues/1287)
+
+## 2.3.0
+
+- Added an experimental autoloader
+- Added the `subpath` argument to `getBasePath()` to make it easier to generate full paths to any file
+- Added `custom-elements.json` to package exports
+- Added `tag__base`, `tag__content`, `tag__remove-button`, `tag__remove-button__base` parts to `<sl-select>`
+- Fixed a bug in `<sl-rating>` that allowed the `sl-change` event to be emitted when disabled [#1220](https://github.com/shoelace-style/shoelace/issues/1220)
+- Fixed a regression in `<sl-input>` that caused `min` and `max` to stop working when `type="date"` [#1224](https://github.com/shoelace-style/shoelace/issues/1224)
+- Improved accessibility of `<sl-carousel>` [#1218](https://github.com/shoelace-style/shoelace/pull/1218)
+- Improved `<sl-option>` so it converts non-string values to strings for convenience [#1226](https://github.com/shoelace-style/shoelace/issues/1226)
+- Updated the docs to dogfood the autoloader
+
+## 2.2.0
+
+- Added TypeScript types to all custom events [#1183](https://github.com/shoelace-style/shoelace/pull/1183)
+- Added the `svg` part to `<sl-icon>`
+- Added the `getForm()` method to all form controls [#1180](https://github.com/shoelace-style/shoelace/issues/1180)
+- Added the experimental carousel component [#851](https://github.com/shoelace-style/shoelace/pull/851)
+- Fixed a bug in `<sl-select>` that caused the display label to render incorrectly in Chrome after form validation [#1197](https://github.com/shoelace-style/shoelace/discussions/1197)
+- Fixed a bug in `<sl-input>` that prevented users from applying their own value for `autocapitalize`, `autocomplete`, and `autocorrect` when using `type="password` [#1205](https://github.com/shoelace-style/shoelace/issues/1205)
+- Fixed a bug in `<sl-tab-group>` that prevented scroll controls from showing when dynamically adding tabs [#1208](https://github.com/shoelace-style/shoelace/issues/1208)
+- Fixed a bug in `<sl-input>` that caused the calendar icon to be clipped in Firefox [#1213](https://github.com/shoelace-style/shoelace/pull/1213)
+- Fixed a bug in `<sl-tab>` that caused `sl-tab-show` to be emitted when activating the close button
+- Fixed a bug in `<sl-spinner>` that caused `--track-color` to be invisible with certain colors
+- Fixed a bug in `<sl-menu-item>` that caused the focus color to show when selecting menu items with a mouse or touch device
+- Fixed a bug in `<sl-select>` that caused `sl-change` and `sl-input` to be emitted too early [#1201](https://github.com/shoelace-style/shoelace/issues/1201)
+- Fixed a positioning edge case that caused `<sl-popup>` to positioned nested popups incorrectly [#1135](https://github.com/shoelace-style/shoelace/issues/1135)
+- Fixed a bug in `<sl-tree>` that caused the tree item to collapse when clicking a child item, dragging the mouse, and releasing it on the parent node [#1082](https://github.com/shoelace-style/shoelace/issues/1082)
+- Updated `@shoelace-style/localize` to 3.1.0
+- Updated `@floating-ui/dom` to 1.2.1
+
+When using `<input type="password">` the default value for `autocapitalize`, `autocomplete`, and `autocorrect` may be affected due to the bug fixed in [#1205](https://github.com/shoelace-style/shoelace/issues/1205). For any affected users, setting these attributes to `off` will restore the previous behavior.
+
 ## 2.1.0
 
 - Added the `sl-focus` and `sl-blur` events to `<sl-color-picker>`
@@ -273,8 +326,7 @@ This release removes the `<sl-responsive-media>` component. When this component
 - Fixed a bug in `<sl-tree>` that prevented the keyboard from working when the component was nested in a shadow root [#871](https://github.com/shoelace-style/shoelace/issues/871)
 - Fixed a bug in `<sl-tab-group>` that prevented the keyboard from working when the component was nested in a shadow root [#872](https://github.com/shoelace-style/shoelace/issues/872)
 - Fixed a bug in `<sl-tab>` that allowed disabled tabs to erroneously receive focus
-- Improved single selection in `<sl-tree>` so nodes expand and collapse and rece
-  ive selection when clicking on the label
+- Improved single selection in `<sl-tree>` so nodes expand and collapse and receive selection when clicking on the label
 - Renamed `expanded-icon` and `collapsed-icon` slots to `expand-icon` and `collapse-icon` in the experimental `<sl-tree>` and `<sl-tree-item>` components
 - Improved RTL support for `<sl-image-comparer>`
 - Refactored components to extend from `ShoelaceElement` to make `dir` and `lang` reactive properties in all components

docs/resources/contributing.md

@@ -363,3 +363,26 @@ Avoid inlining SVG icons inside of templates. If a component requires an icon, m
 ```
 
 This will render the icons instantly whereas the default library will fetch them from a remote source. If an icon isn't available in the system library, you will need to add it to `library.system.ts`. Using the system library ensures that all icons load instantly and are customizable by users who wish to provide a custom resolver for the system library.
+
+### Writing tests
+
+What to test for a given component:
+
+- Start with a simple test that checks that the default version of the component still renders.
+- Add at least one accessibility test (The accessibility check only covers the parts of the DOM which are currently visible and rendered. Depending on the component, more than one accessibility test is required to cover all scenarios.):
+
+```ts
+const myComponent = await fixture<SlAlert>(html`<sl-my-component>SomeContent</sl-my-component>`);
+
+await expect(myComponent).to.be.accessible();
+```
+
+- Try to cover all features advertised in the component's description
+
+Guidelines for writing tests:
+
+- Each test should declare its own, hand crafted hml fixture for the component. Do not try to write one big component to match all tests. This helps keeping each test understandable in isolation.
+- Tests should not produce log lines. Note that sometimes this cannot be prevented as the test runner might log errors (e.g. 404s).
+- Try keeping the main test readable: Extract more complicated sets of selectors/commands/assertions into separate functions.
+- Try to aim testing the user facing features of the component instead of the internal workings of the component.
+- Group multiple tests for one feature into describe blocks.

package-lock.json

@@ -1,19 +1,20 @@
 {
   "name": "@shoelace-style/shoelace",
-  "version": "2.1.0",
+  "version": "2.4.0",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "@shoelace-style/shoelace",
-      "version": "2.1.0",
+      "version": "2.4.0",
       "license": "MIT",
       "dependencies": {
         "@ctrl/tinycolor": "^3.5.0",
-        "@floating-ui/dom": "^1.1.0",
+        "@floating-ui/dom": "^1.2.1",
         "@lit-labs/react": "^1.1.1",
         "@shoelace-style/animations": "^1.1.0",
-        "@shoelace-style/localize": "^3.0.4",
+        "@shoelace-style/localize": "^3.1.0",
+        "composed-offset-position": "^0.0.4",
         "lit": "^2.6.1",
         "qr-creator": "^1.0.0"
       },
@@ -55,7 +56,6 @@
         "lint-staged": "^13.1.0",
         "lunr": "^2.3.9",
         "npm-check-updates": "^16.6.2",
-        "open": "^8.4.0",
         "pascal-case": "^3.1.2",
         "plop": "^3.1.1",
         "prettier": "^2.8.2",
@@ -1043,16 +1043,16 @@
       }
     },
     "node_modules/@floating-ui/core": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/@floating-ui/core/-/core-1.1.0.tgz",
-      "integrity": "sha512-zbsLwtnHo84w1Kc8rScAo5GMk1GdecSlrflIbfnEBJwvTSj1SL6kkOYV+nHraMCPEy+RNZZUaZyL8JosDGCtGQ=="
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@floating-ui/core/-/core-1.2.1.tgz",
+      "integrity": "sha512-LSqwPZkK3rYfD7GKoIeExXOyYx6Q1O4iqZWwIehDNuv3Dv425FIAE8PRwtAx1imEolFTHgBEcoFHm9MDnYgPCg=="
     },
     "node_modules/@floating-ui/dom": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/@floating-ui/dom/-/dom-1.1.0.tgz",
-      "integrity": "sha512-TSogMPVxbRe77QCj1dt8NmRiJasPvuc+eT5jnJ6YpLqgOD2zXc5UA3S1qwybN+GVCDNdKfpKy1oj8RpzLJvh6A==",
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@floating-ui/dom/-/dom-1.2.1.tgz",
+      "integrity": "sha512-Rt45SmRiV8eU+xXSB9t0uMYiQ/ZWGE/jumse2o3i5RGlyvcbqOF4q+1qBnzLE2kZ5JGhq0iMkcGXUKbFe7MpTA==",
       "dependencies": {
-        "@floating-ui/core": "^1.0.5"
+        "@floating-ui/core": "^1.2.1"
       }
     },
     "node_modules/@gar/promisify": {
@@ -1478,9 +1478,9 @@
       }
     },
     "node_modules/@shoelace-style/localize": {
-      "version": "3.0.4",
-      "resolved": "https://registry.npmjs.org/@shoelace-style/localize/-/localize-3.0.4.tgz",
-      "integrity": "sha512-HFY90KD+b1Td2otSBryCOpQjBEArIwlV6Tv4J4rC/E/D5wof2eLF6JUVrbiRNn8GRmwATe4YDAEK7NUD08xO1w=="
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/@shoelace-style/localize/-/localize-3.1.0.tgz",
+      "integrity": "sha512-evGxn5wIQh1/Ks1RbZm7rY4DxPKAUnXKTixZNgnYV/N2V8Bbbvsi+S14gNa42SQNUJK5WooNtlar2B8cehEwZQ=="
     },
     "node_modules/@sindresorhus/is": {
       "version": "0.7.0",
@@ -4523,6 +4523,11 @@
       "integrity": "sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg==",
       "dev": true
     },
+    "node_modules/composed-offset-position": {
+      "version": "0.0.4",
+      "resolved": "https://registry.npmjs.org/composed-offset-position/-/composed-offset-position-0.0.4.tgz",
+      "integrity": "sha512-vMlvu1RuNegVE0YsCDSV/X4X10j56mq7PCIyOKK74FxkXzGLwhOUmdkJLSdOBOMwWycobGUMgft2lp+YgTe8hw=="
+    },
     "node_modules/compress-brotli": {
       "version": "1.3.8",
       "resolved": "https://registry.npmjs.org/compress-brotli/-/compress-brotli-1.3.8.tgz",
@@ -16270,16 +16275,16 @@
       }
     },
     "@floating-ui/core": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/@floating-ui/core/-/core-1.1.0.tgz",
-      "integrity": "sha512-zbsLwtnHo84w1Kc8rScAo5GMk1GdecSlrflIbfnEBJwvTSj1SL6kkOYV+nHraMCPEy+RNZZUaZyL8JosDGCtGQ=="
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@floating-ui/core/-/core-1.2.1.tgz",
+      "integrity": "sha512-LSqwPZkK3rYfD7GKoIeExXOyYx6Q1O4iqZWwIehDNuv3Dv425FIAE8PRwtAx1imEolFTHgBEcoFHm9MDnYgPCg=="
     },
     "@floating-ui/dom": {
-      "version": "1.1.0",
-      "resolved": "https://registry.npmjs.org/@floating-ui/dom/-/dom-1.1.0.tgz",
-      "integrity": "sha512-TSogMPVxbRe77QCj1dt8NmRiJasPvuc+eT5jnJ6YpLqgOD2zXc5UA3S1qwybN+GVCDNdKfpKy1oj8RpzLJvh6A==",
+      "version": "1.2.1",
+      "resolved": "https://registry.npmjs.org/@floating-ui/dom/-/dom-1.2.1.tgz",
+      "integrity": "sha512-Rt45SmRiV8eU+xXSB9t0uMYiQ/ZWGE/jumse2o3i5RGlyvcbqOF4q+1qBnzLE2kZ5JGhq0iMkcGXUKbFe7MpTA==",
       "requires": {
-        "@floating-ui/core": "^1.0.5"
+        "@floating-ui/core": "^1.2.1"
       }
     },
     "@gar/promisify": {
@@ -16623,9 +16628,9 @@
       "integrity": "sha512-Be+cahtZyI2dPKRm8EZSx3YJQ+jLvEcn3xzRP7tM4tqBnvd/eW/64Xh0iOf0t2w5P8iJKfdBbpVNE9naCaOf2g=="
     },
     "@shoelace-style/localize": {
-      "version": "3.0.4",
-      "resolved": "https://registry.npmjs.org/@shoelace-style/localize/-/localize-3.0.4.tgz",
-      "integrity": "sha512-HFY90KD+b1Td2otSBryCOpQjBEArIwlV6Tv4J4rC/E/D5wof2eLF6JUVrbiRNn8GRmwATe4YDAEK7NUD08xO1w=="
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/@shoelace-style/localize/-/localize-3.1.0.tgz",
+      "integrity": "sha512-evGxn5wIQh1/Ks1RbZm7rY4DxPKAUnXKTixZNgnYV/N2V8Bbbvsi+S14gNa42SQNUJK5WooNtlar2B8cehEwZQ=="
     },
     "@sindresorhus/is": {
       "version": "0.7.0",
@@ -18941,6 +18946,11 @@
       "integrity": "sha512-Rd3se6QB+sO1TwqZjscQrurpEPIfO0/yYnSin6Q/rD3mOutHvUrCAhJub3r90uNb+SESBuE0QYoB90YdfatsRg==",
       "dev": true
     },
+    "composed-offset-position": {
+      "version": "0.0.4",
+      "resolved": "https://registry.npmjs.org/composed-offset-position/-/composed-offset-position-0.0.4.tgz",
+      "integrity": "sha512-vMlvu1RuNegVE0YsCDSV/X4X10j56mq7PCIyOKK74FxkXzGLwhOUmdkJLSdOBOMwWycobGUMgft2lp+YgTe8hw=="
+    },
     "compress-brotli": {
       "version": "1.3.8",
       "resolved": "https://registry.npmjs.org/compress-brotli/-/compress-brotli-1.3.8.tgz",

package.json

@@ -1,7 +1,7 @@
 {
   "name": "@shoelace-style/shoelace",
   "description": "A forward-thinking library of web components.",
-  "version": "2.1.0",
+  "version": "2.4.0",
   "homepage": "https://github.com/shoelace-style/shoelace",
   "author": "Cory LaViska",
   "license": "MIT",
@@ -14,6 +14,7 @@
       "types": "./dist/shoelace.d.ts",
       "import": "./dist/shoelace.js"
     },
+    "./dist/custom-elements.json": "./dist/custom-elements.json",
     "./dist/themes/*": "./dist/themes/*",
     "./dist/components/*": "./dist/components/*",
     "./dist/utilities/*": "./dist/utilities/*",
@@ -63,10 +64,11 @@
   },
   "dependencies": {
     "@ctrl/tinycolor": "^3.5.0",
-    "@floating-ui/dom": "^1.1.0",
+    "@floating-ui/dom": "^1.2.1",
     "@lit-labs/react": "^1.1.1",
     "@shoelace-style/animations": "^1.1.0",
-    "@shoelace-style/localize": "^3.0.4",
+    "@shoelace-style/localize": "^3.1.0",
+    "composed-offset-position": "^0.0.4",
     "lit": "^2.6.1",
     "qr-creator": "^1.0.0"
   },
@@ -108,7 +110,6 @@
     "lint-staged": "^13.1.0",
     "lunr": "^2.3.9",
     "npm-check-updates": "^16.6.2",
-    "open": "^8.4.0",
     "pascal-case": "^3.1.2",
     "plop": "^3.1.1",
     "prettier": "^2.8.2",

scripts/build.js

@@ -7,7 +7,6 @@ import esbuild from 'esbuild';
 import fs from 'fs';
 import getPort, { portNumbers } from 'get-port';
 import { globby } from 'globby';
-import open from 'open';
 import copy from 'recursive-copy';
 
 const { bundle, copydir, dir, serve, types } = commandLineArgs([
@@ -51,6 +50,8 @@ fs.mkdirSync(outdir, { recursive: true });
         //
         // The whole shebang
         './src/shoelace.ts',
+        // The auto-loader
+        './src/shoelace-autoloader.ts',
         // Components
         ...(await globby('./src/components/**/!(*.(style|test)).ts')),
         // Translations
@@ -106,7 +107,6 @@ fs.mkdirSync(outdir, { recursive: true });
     deleteSync('docs/dist');
 
     const browserSyncConfig = {
-      open: false,
       startPath: '/',
       port,
       logLevel: 'silent',
@@ -120,6 +120,22 @@ fs.mkdirSync(outdir, { recursive: true });
         routes: {
           '/dist': './dist'
         }
+      },
+      //
+      // Suppress Chrome's document.write() warning
+      //
+      // More info: https://github.com/BrowserSync/browser-sync/issues/1600)
+      //
+      snippetOptions: {
+        rule: {
+          match: /<\/head>/u,
+          fn: (snippet, match) => {
+            const {
+              groups: { src }
+            } = /src='(?<src>[^']+)'/u.exec(snippet);
+            return `<script src="${src}" async></script>${match}`;
+          }
+        }
       }
     };
 
@@ -127,7 +143,6 @@ fs.mkdirSync(outdir, { recursive: true });
     bs.init(browserSyncConfig, () => {
       const url = `http://localhost:${port}`;
       console.log(chalk.cyan(`Launched the Shoelace dev server at ${url} 🥾\n`));
-      open(url);
     });
 
     // Rebuild and reload when source files change

src/components/animated-image/animated-image.test.ts

@@ -1,9 +1,70 @@
-import { expect, fixture, html } from '@open-wc/testing';
+import { clickOnElement } from '../../internal/test';
+import { expect, fixture, html, oneEvent } from '@open-wc/testing';
+import type SlAnimatedImage from './animated-image';
 
 describe('<sl-animated-image>', () => {
   it('should render a component', async () => {
-    const el = await fixture(html` <sl-animated-image></sl-animated-image> `);
+    const animatedImage = await fixture(html` <sl-animated-image></sl-animated-image> `);
 
-    expect(el).to.exist;
+    expect(animatedImage).to.exist;
+  });
+
+  it('should render be accessible', async () => {
+    const animatedImage = await fixture(html` <sl-animated-image></sl-animated-image> `);
+
+    await expect(animatedImage).to.be.accessible();
+  });
+
+  const files = ['docs/assets/images/walk.gif', 'docs/assets/images/tie.webp'];
+
+  files.forEach((file: string) => {
+    it(`should load a ${file} without errors`, async () => {
+      const animatedImage = await fixture<SlAnimatedImage>(html` <sl-animated-image></sl-animated-image> `);
+      let errorCount = 0;
+      oneEvent(animatedImage, 'sl-error').then(() => errorCount++);
+      await loadImage(animatedImage, file);
+
+      expect(errorCount).to.be.equal(0);
+    });
+
+    it(`should play ${file} on click`, async () => {
+      const animatedImage = await fixture<SlAnimatedImage>(html` <sl-animated-image></sl-animated-image> `);
+      await loadImage(animatedImage, file);
+
+      expect(animatedImage.play).not.to.be.true;
+
+      await clickOnElement(animatedImage);
+
+      expect(animatedImage.play).to.be.true;
+    });
+
+    it(`should pause and resume ${file} on click`, async () => {
+      const animatedImage = await fixture<SlAnimatedImage>(html` <sl-animated-image></sl-animated-image> `);
+      await loadImage(animatedImage, file);
+
+      animatedImage.play = true;
+
+      await clickOnElement(animatedImage);
+
+      expect(animatedImage.play).to.be.false;
+
+      await clickOnElement(animatedImage);
+
+      expect(animatedImage.play).to.be.true;
+    });
+  });
+
+  it('should emit an error event on invalid url', async () => {
+    const animatedImage = await fixture<SlAnimatedImage>(html` <sl-animated-image></sl-animated-image> `);
+
+    const errorPromise = oneEvent(animatedImage, 'sl-error');
+    animatedImage.src = 'completelyWrong';
+
+    await errorPromise;
   });
 });
+async function loadImage(animatedImage: SlAnimatedImage, file: string) {
+  const loadingPromise = oneEvent(animatedImage, 'sl-load');
+  animatedImage.src = file;
+  await loadingPromise;
+}

src/components/animation/animation.test.ts

@@ -0,0 +1,81 @@
+import { aTimeout, expect, fixture, html, oneEvent } from '@open-wc/testing';
+import type SlAnimation from './animation';
+
+describe('<sl-animation>', () => {
+  const boxToAnimate = html`<div style="width: 10px; height: 10px;" data-testid="animated-box"></div>`;
+
+  it('renders', async () => {
+    const animationContainer = await fixture<SlAnimation>(html`<sl-animation>${boxToAnimate}</sl-animation>`);
+
+    expect(animationContainer).to.exist;
+  });
+
+  it('is accessible', async () => {
+    const animationContainer = await fixture<SlAnimation>(html`<sl-animation>${boxToAnimate}</sl-animation>`);
+
+    await expect(animationContainer).to.be.accessible();
+  });
+
+  describe('animation start', () => {
+    it('does not start the animation by default', async () => {
+      const animationContainer = await fixture<SlAnimation>(
+        html`<sl-animation name="bounce" easing="ease-in-out" duration="10">${boxToAnimate}</sl-animation>`
+      );
+      await aTimeout(0);
+
+      expect(animationContainer.play).to.be.false;
+    });
+
+    it('emits the correct event on animation start', async () => {
+      const animationContainer = await fixture<SlAnimation>(
+        html`<sl-animation name="bounce" easing="ease-in-out" duration="10">${boxToAnimate}</sl-animation>`
+      );
+
+      const startPromise = oneEvent(animationContainer, 'sl-start');
+      animationContainer.play = true;
+      return startPromise;
+    });
+  });
+
+  it('emits the correct event on animation end', async () => {
+    const animationContainer = await fixture<SlAnimation>(
+      html`<sl-animation name="bounce" easing="ease-in-out" duration="1">${boxToAnimate}</sl-animation>`
+    );
+
+    const endPromise = oneEvent(animationContainer, 'sl-finish');
+    animationContainer.iterations = 1;
+    animationContainer.play = true;
+    return endPromise;
+  });
+
+  it('can be finished by hand', async () => {
+    const animationContainer = await fixture<SlAnimation>(
+      html`<sl-animation name="bounce" easing="ease-in-out" duration="1000">${boxToAnimate}</sl-animation>`
+    );
+
+    const endPromise = oneEvent(animationContainer, 'sl-finish');
+    animationContainer.iterations = 1;
+    animationContainer.play = true;
+
+    await aTimeout(0);
+
+    animationContainer.finish();
+    return endPromise;
+  });
+
+  it('can be cancelled', async () => {
+    const animationContainer = await fixture<SlAnimation>(
+      html`<sl-animation name="bounce" easing="ease-in-out" duration="1">${boxToAnimate}</sl-animation>`
+    );
+    let animationHasFinished = false;
+    oneEvent(animationContainer, 'sl-finish').then(() => (animationHasFinished = true));
+    const cancelPromise = oneEvent(animationContainer, 'sl-cancel');
+    animationContainer.play = true;
+
+    await aTimeout(0);
+    animationContainer.cancel();
+
+    await cancelPromise;
+    expect(animationHasFinished).to.be.false;
+  });
+});

src/components/avatar/avatar.test.ts

@@ -1,5 +1,4 @@
-import { expect, fixture, html, waitUntil } from '@open-wc/testing';
-import sinon from 'sinon';
+import { aTimeout, expect, fixture, html, waitUntil } from '@open-wc/testing';
 import type SlAvatar from './avatar';
 
 // The default avatar background just misses AA contrast, but the next step up is way too dark. Since avatars aren't
@@ -73,6 +72,46 @@ describe('<sl-avatar>', () => {
     });
   });
 
+  describe('when image is present, the initials or icon part should not render', () => {
+    const initials = 'SL';
+    const image = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
+    const label = 'Small transparent square';
+    before(async () => {
+      el = await fixture<SlAvatar>(
+        html`<sl-avatar image="${image}" label="${label}" initials="${initials}"></sl-avatar>`
+      );
+    });
+
+    it('should pass accessibility tests', async () => {
+      /**
+       * The image element itself is ancillary, because it's parent container contains the
+       * aria-label which dictates what "sl-avatar" is. This also implies that label text will
+       * resolve to "" when not provided and ignored by readers. This is why we use alt="" on
+       * the image element to pass accessibility.
+       * https://html.spec.whatwg.org/multipage/images.html#ancillary-images
+       */
+      await expect(el).to.be.accessible({ ignoredRules });
+    });
+
+    it('renders "image" part, with src and a role of presentation', () => {
+      const part = el.shadowRoot!.querySelector('[part~="image"]')!;
+
+      expect(part.getAttribute('src')).to.eq(image);
+    });
+
+    it('should not render the initials part', () => {
+      const part = el.shadowRoot!.querySelector<HTMLElement>('[part~="initials"]')!;
+
+      expect(part).to.not.exist;
+    });
+
+    it('should not render the icon part', () => {
+      const slot = el.shadowRoot!.querySelector<HTMLSlotElement>('slot[name=icon]')!;
+
+      expect(slot).to.not.exist;
+    });
+  });
+
   ['square', 'rounded', 'circle'].forEach(shape => {
     describe(`when passed a shape attribute ${shape}`, () => {
       before(async () => {
@@ -113,23 +152,20 @@ describe('<sl-avatar>', () => {
   });
 
   it('should not render the image when the image fails to load', async () => {
-    const errorHandler = sinon.spy();
-
     el = await fixture<SlAvatar>(html`<sl-avatar></sl-avatar>`);
-    el.addEventListener('error', errorHandler);
     el.image = 'bad_image';
-    waitUntil(() => errorHandler.calledOnce);
 
+    await aTimeout(0);
+
+    await waitUntil(() => el.shadowRoot!.querySelector('img') === null);
     expect(el.shadowRoot!.querySelector('img')).to.be.null;
   });
 
   it('should show a valid image after being passed an invalid image initially', async () => {
-    const errorHandler = sinon.spy();
-
     el = await fixture<SlAvatar>(html`<sl-avatar></sl-avatar>`);
-    el.addEventListener('error', errorHandler);
-    el.image = 'bad_image';
-    waitUntil(() => errorHandler.calledOnce);
+
+    await aTimeout(0);
+    await waitUntil(() => el.shadowRoot!.querySelector('img') === null);
 
     el.image = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7';
     await el.updateComplete;

src/components/avatar/avatar.ts

@@ -52,6 +52,29 @@ export default class SlAvatar extends ShoelaceElement {
   }
 
   render() {
+    const avatarWithImage = html`
+      <img
+        part="image"
+        class="avatar__image"
+        src="${this.image}"
+        loading="${this.loading}"
+        alt=""
+        @error="${() => (this.hasError = true)}"
+      />
+    `;
+
+    let avatarWithoutImage = html``;
+
+    if (this.initials) {
+      avatarWithoutImage = html`<div part="initials" class="avatar__initials">${this.initials}</div>`;
+    } else {
+      avatarWithoutImage = html`
+        <slot name="icon" part="icon" class="avatar__icon" aria-hidden="true">
+          <sl-icon name="person-fill" library="system"></sl-icon>
+        </slot>
+      `;
+    }
+
     return html`
       <div
         part="base"
@@ -64,25 +87,7 @@ export default class SlAvatar extends ShoelaceElement {
         role="img"
         aria-label=${this.label}
       >
-        ${this.initials
-          ? html` <div part="initials" class="avatar__initials">${this.initials}</div> `
-          : html`
-              <slot name="icon" part="icon" class="avatar__icon" aria-hidden="true">
-                <sl-icon name="person-fill" library="system"></sl-icon>
-              </slot>
-            `}
-        ${this.image && !this.hasError
-          ? html`
-              <img
-                part="image"
-                class="avatar__image"
-                src="${this.image}"
-                loading="${this.loading}"
-                alt=""
-                @error="${() => (this.hasError = true)}"
-              />
-            `
-          : ''}
+        ${this.image && !this.hasError ? avatarWithImage : avatarWithoutImage}
       </div>
     `;
   }

src/components/button-group/button-group.ts

@@ -28,22 +28,22 @@ export default class SlButtonGroup extends ShoelaceElement {
    */
   @property() label = '';
 
-  private handleFocus(event: CustomEvent) {
+  private handleFocus(event: Event) {
     const button = findButton(event.target as HTMLElement);
     button?.classList.add('sl-button-group__button--focus');
   }
 
-  private handleBlur(event: CustomEvent) {
+  private handleBlur(event: Event) {
     const button = findButton(event.target as HTMLElement);
     button?.classList.remove('sl-button-group__button--focus');
   }
 
-  private handleMouseOver(event: CustomEvent) {
+  private handleMouseOver(event: Event) {
     const button = findButton(event.target as HTMLElement);
     button?.classList.add('sl-button-group__button--hover');
   }
 
-  private handleMouseOut(event: CustomEvent) {
+  private handleMouseOut(event: Event) {
     const button = findButton(event.target as HTMLElement);
     button?.classList.remove('sl-button-group__button--hover');
   }

src/components/button/button.ts

@@ -257,6 +257,11 @@ export default class SlButton extends ShoelaceElement implements ShoelaceFormCon
     return true;
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     if (this.isButton()) {

src/components/carousel-item/carousel-item.styles.ts

@@ -0,0 +1,26 @@
+import { css } from 'lit';
+import componentStyles from '../../styles/component.styles';
+
+export default css`
+  ${componentStyles}
+
+  :host {
+    --aspect-ratio: inherit;
+
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    flex-direction: column;
+    width: 100%;
+    max-height: 100%;
+    aspect-ratio: var(--aspect-ratio);
+    scroll-snap-align: start;
+    scroll-snap-stop: always;
+  }
+
+  ::slotted(img) {
+    width: 100%;
+    height: 100%;
+    object-fit: cover;
+  }
+`;

src/components/carousel-item/carousel-item.test.ts

@@ -0,0 +1,17 @@
+import { expect, fixture, html } from '@open-wc/testing';
+
+describe('<sl-carousel-item>', () => {
+  it('should render a component', async () => {
+    const el = await fixture(html` <sl-carousel-item></sl-carousel-item> `);
+
+    expect(el).to.exist;
+  });
+
+  it('should pass accessibility tests', async () => {
+    // Arrange
+    const el = await fixture(html` <div role="list"><sl-carousel-item></sl-carousel-item></div> `);
+
+    // Assert
+    await expect(el).to.be.accessible();
+  });
+});

src/components/carousel-item/carousel-item.ts

@@ -0,0 +1,40 @@
+import { customElement } from 'lit/decorators.js';
+import { html } from 'lit';
+import ShoelaceElement from '../../internal/shoelace-element';
+import styles from './carousel-item.styles';
+import type { CSSResultGroup } from 'lit';
+
+/**
+ * @summary A carousel item represent a slide within a [carousel](/components/carousel).
+ *
+ * @since 2.0
+ * @status experimental
+ *
+ * @slot - The carousel item's content..
+ *
+ * @cssproperty --aspect-ratio - The slide's aspect ratio. Inherited from the carousel by default.
+ *
+ */
+@customElement('sl-carousel-item')
+export default class SlCarouselItem extends ShoelaceElement {
+  static styles: CSSResultGroup = styles;
+
+  static isCarouselItem(node: Node) {
+    return node instanceof Element && node.getAttribute('aria-roledescription') === 'slide';
+  }
+
+  connectedCallback() {
+    super.connectedCallback();
+    this.setAttribute('role', 'group');
+  }
+
+  render() {
+    return html` <slot></slot> `;
+  }
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'sl-carousel-item': SlCarouselItem;
+  }
+}

src/components/carousel/autoplay-controller.ts

@@ -0,0 +1,73 @@
+import type { ReactiveController, ReactiveElement } from 'lit';
+
+/**
+ * A controller that repeatedly calls the specified callback with the provided interval time.
+ * The timer is automatically paused while the user is interacting with the component.
+ */
+export class AutoplayController implements ReactiveController {
+  private host: ReactiveElement;
+  private timerId = 0;
+  private tickCallback: () => void;
+  private activeInteractions = 0;
+
+  paused = false;
+  stopped = true;
+
+  constructor(host: ReactiveElement, tickCallback: () => void) {
+    host.addController(this);
+
+    this.host = host;
+    this.tickCallback = tickCallback;
+  }
+
+  hostConnected(): void {
+    this.host.addEventListener('mouseenter', this.pause);
+    this.host.addEventListener('mouseleave', this.resume);
+    this.host.addEventListener('focusin', this.pause);
+    this.host.addEventListener('focusout', this.resume);
+    this.host.addEventListener('touchstart', this.pause, { passive: true });
+    this.host.addEventListener('touchend', this.resume);
+  }
+
+  hostDisconnected(): void {
+    this.stop();
+
+    this.host.removeEventListener('mouseenter', this.pause);
+    this.host.removeEventListener('mouseleave', this.resume);
+    this.host.removeEventListener('focusin', this.pause);
+    this.host.removeEventListener('focusout', this.resume);
+    this.host.removeEventListener('touchstart', this.pause);
+    this.host.removeEventListener('touchend', this.resume);
+  }
+
+  start(interval: number) {
+    this.stop();
+
+    this.stopped = false;
+    this.timerId = window.setInterval(() => {
+      if (!this.paused) {
+        this.tickCallback();
+      }
+    }, interval);
+  }
+
+  stop() {
+    clearInterval(this.timerId);
+    this.stopped = true;
+    this.host.requestUpdate();
+  }
+
+  pause = () => {
+    if (!this.activeInteractions++) {
+      this.paused = true;
+      this.host.requestUpdate();
+    }
+  };
+
+  resume = () => {
+    if (!--this.activeInteractions) {
+      this.paused = false;
+      this.host.requestUpdate();
+    }
+  };
+}

src/components/carousel/carousel.styles.ts

@@ -0,0 +1,160 @@
+import { css } from 'lit';
+import componentStyles from '../../styles/component.styles';
+
+export default css`
+  ${componentStyles}
+
+  :host {
+    --slide-gap: var(--sl-spacing-medium, 1rem);
+    --aspect-ratio: 16 / 9;
+    --scroll-hint: 0px;
+
+    display: flex;
+  }
+
+  .carousel {
+    display: grid;
+    grid-template-columns: min-content 1fr min-content;
+    grid-template-rows: 1fr min-content;
+    grid-template-areas:
+      '. slides .'
+      '. pagination .';
+    gap: var(--sl-spacing-medium);
+    align-items: center;
+    min-height: 100%;
+    min-width: 100%;
+    position: relative;
+  }
+
+  .carousel__pagination {
+    grid-area: pagination;
+    display: flex;
+    flex-wrap: wrap;
+    justify-content: center;
+    gap: var(--sl-spacing-small);
+  }
+
+  .carousel__slides {
+    grid-area: slides;
+
+    display: grid;
+    height: 100%;
+    width: 100%;
+    align-items: center;
+    justify-items: center;
+    overflow: auto;
+    overscroll-behavior-x: contain;
+    scrollbar-width: none;
+    aspect-ratio: calc(var(--aspect-ratio) * var(--slides-per-page));
+    border-radius: var(--sl-border-radius-small);
+
+    --slide-size: calc((100% - (var(--slides-per-page) - 1) * var(--slide-gap)) / var(--slides-per-page));
+  }
+
+  @media (prefers-reduced-motion) {
+    :where(.carousel__slides) {
+      scroll-behavior: auto;
+    }
+  }
+
+  .carousel__slides--horizontal {
+    grid-auto-flow: column;
+    grid-auto-columns: var(--slide-size);
+    grid-auto-rows: 100%;
+    column-gap: var(--slide-gap);
+    scroll-snap-type: x mandatory;
+    scroll-padding-inline: var(--scroll-hint);
+    padding-inline: var(--scroll-hint);
+    overflow-y: hidden;
+  }
+
+  .carousel__slides--vertical {
+    grid-auto-flow: row;
+    grid-auto-columns: 100%;
+    grid-auto-rows: var(--slide-size);
+    row-gap: var(--slide-gap);
+    scroll-snap-type: y mandatory;
+    scroll-padding-block: var(--scroll-hint);
+    padding-block: var(--scroll-hint);
+    overflow-x: hidden;
+  }
+
+  .carousel__slides--dragging,
+  .carousel__slides--dropping {
+    scroll-snap-type: unset;
+  }
+
+  :host([vertical]) ::slotted(sl-carousel-item) {
+    height: 100%;
+  }
+
+  .carousel__slides::-webkit-scrollbar {
+    display: none;
+  }
+
+  .carousel__navigation {
+    grid-area: navigation;
+    display: contents;
+    font-size: var(--sl-font-size-x-large);
+  }
+
+  .carousel__navigation-button {
+    flex: 0 0 auto;
+    display: flex;
+    align-items: center;
+    background: none;
+    border: none;
+    border-radius: var(--sl-border-radius-small);
+    font-size: inherit;
+    color: var(--sl-color-neutral-600);
+    padding: var(--sl-spacing-x-small);
+    cursor: pointer;
+    transition: var(--sl-transition-medium) color;
+    appearance: none;
+  }
+
+  .carousel__navigation-button--disabled {
+    opacity: 0.5;
+    cursor: not-allowed;
+  }
+
+  .carousel__navigation-button--disabled::part(base) {
+    pointer-events: none;
+  }
+
+  .carousel__navigation-button--previous {
+    grid-column: 1;
+    grid-row: 1;
+  }
+
+  .carousel__navigation-button--next {
+    grid-column: 3;
+    grid-row: 1;
+  }
+
+  .carousel__pagination-item {
+    display: block;
+    cursor: pointer;
+    background: none;
+    border: 0;
+    border-radius: var(--sl-border-radius-circle);
+    width: var(--sl-spacing-small);
+    height: var(--sl-spacing-small);
+    background-color: var(--sl-color-neutral-300);
+    padding: 0;
+    margin: 0;
+  }
+
+  .carousel__pagination-item--active {
+    background-color: var(--sl-color-neutral-700);
+    transform: scale(1.2);
+  }
+
+  /* Focus styles */
+  .carousel__slides:focus-visible,
+  .carousel__navigation-button:focus-visible,
+  .carousel__pagination-item:focus-visible {
+    outline: var(--sl-focus-ring);
+    outline-offset: var(--sl-focus-ring-offset);
+  }
+`;

src/components/carousel/carousel.test.ts

@@ -0,0 +1,588 @@
+import { clickOnElement } from '../../internal/test';
+import { expect, fixture, html, oneEvent } from '@open-wc/testing';
+import sinon from 'sinon';
+import type SlCarousel from './carousel';
+
+describe('<sl-carousel>', () => {
+  it('should render a carousel with default configuration', async () => {
+    // Arrange
+    const el = await fixture(html`
+      <sl-carousel>
+        <sl-carousel-item>Node 1</sl-carousel-item>
+        <sl-carousel-item>Node 2</sl-carousel-item>
+        <sl-carousel-item>Node 3</sl-carousel-item>
+      </sl-carousel>
+    `);
+
+    // Assert
+    expect(el).to.exist;
+    expect(el).to.have.attribute('role', 'region');
+    expect(el).to.have.attribute('aria-label', 'Carousel');
+    expect(el.shadowRoot!.querySelector('.carousel__navigation')).not.to.exist;
+    expect(el.shadowRoot!.querySelector('.carousel__pagination')).not.to.exist;
+  });
+
+  describe('when `autoplay` attribute is provided', () => {
+    let clock: sinon.SinonFakeTimers;
+
+    beforeEach(() => {
+      clock = sinon.useFakeTimers({
+        now: new Date()
+      });
+    });
+
+    afterEach(() => {
+      clock.restore();
+    });
+
+    it('should scroll forwards every `autoplay-interval` milliseconds', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel autoplay autoplay-interval="10">
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+      sinon.stub(el, 'next');
+
+      await el.updateComplete;
+
+      // Act
+      clock.next();
+      clock.next();
+
+      // Assert
+      expect(el.next).to.have.been.calledTwice;
+    });
+
+    it('should pause the autoplay while the user is interacting', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel autoplay autoplay-interval="10">
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+      sinon.stub(el, 'next');
+
+      await el.updateComplete;
+
+      // Act
+      el.dispatchEvent(new Event('mouseenter'));
+      await el.updateComplete;
+      clock.next();
+      clock.next();
+
+      // Assert
+      expect(el.next).not.to.have.been.called;
+    });
+
+    it('should not resume if the user is still interacting', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel autoplay autoplay-interval="10">
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+      sinon.stub(el, 'next');
+
+      await el.updateComplete;
+
+      // Act
+      el.dispatchEvent(new Event('mouseenter'));
+      el.dispatchEvent(new Event('focusin'));
+      await el.updateComplete;
+
+      el.dispatchEvent(new Event('mouseleave'));
+      await el.updateComplete;
+
+      clock.next();
+      clock.next();
+
+      // Assert
+      expect(el.next).not.to.have.been.called;
+    });
+  });
+
+  describe('when `loop` attribute is provided', () => {
+    it('should create clones of the first and last slides', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel loop>
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+
+      // Act
+      await el.updateComplete;
+
+      // Assert
+      expect(el.firstElementChild).to.have.attribute('data-clone', '2');
+      expect(el.lastElementChild).to.have.attribute('data-clone', '0');
+    });
+
+    describe('and `slides-per-page` is provided', () => {
+      it('should create multiple clones', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel loop slides-per-page="2">
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+
+        // Act
+        await el.updateComplete;
+        const clones = [...el.children].filter(child => child.hasAttribute('data-clone'));
+
+        // Assert
+        expect(clones).to.have.lengthOf(4);
+      });
+    });
+  });
+
+  describe('when `pagination` attribute is provided', () => {
+    it('should render pagination controls', async () => {
+      // Arrange
+      const el = await fixture(html`
+        <sl-carousel pagination>
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+
+      // Assert
+      expect(el).to.exist;
+      expect(el.shadowRoot!.querySelector('.carousel__navigation')).not.to.exist;
+      expect(el.shadowRoot!.querySelector('.carousel__pagination')).to.exist;
+    });
+
+    describe('and user clicks on a pagination button', () => {
+      it('should scroll the carousel to the nth slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel pagination>
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+        sinon.stub(el, 'goToSlide');
+        await el.updateComplete;
+
+        // Act
+        const paginationItem = el.shadowRoot!.querySelectorAll('.carousel__pagination-item')[2] as HTMLElement;
+        await clickOnElement(paginationItem);
+
+        expect(el.goToSlide).to.have.been.calledWith(2);
+      });
+    });
+  });
+
+  describe('when `navigation` attribute is provided', () => {
+    it('should render navigation controls', async () => {
+      // Arrange
+      const el = await fixture(html`
+        <sl-carousel navigation>
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+
+      // Assert
+      expect(el).to.exist;
+      expect(el.shadowRoot!.querySelector('.carousel__navigation')).to.exist;
+      expect(el.shadowRoot!.querySelector('.carousel__pagination')).not.to.exist;
+    });
+  });
+
+  describe('when `slides-per-page` attribute is provided', () => {
+    it('should show multiple slides at a given time', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel slides-per-page="2">
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+
+      // Act
+      await el.updateComplete;
+
+      // Assert
+      expect(el.scrollContainer.style.getPropertyValue('--slides-per-page').trim()).to.be.equal('2');
+    });
+  });
+
+  describe('when `slides-per-move` attribute is provided', () => {
+    it('should set the granularity of snapping', async () => {
+      // Arrange
+      const expectedSnapGranularity = 2;
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel slides-per-move="${expectedSnapGranularity}">
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+          <sl-carousel-item>Node 4</sl-carousel-item>
+        </sl-carousel>
+      `);
+
+      // Act
+      await el.updateComplete;
+
+      // Assert
+      for (let i = 0; i < el.children.length; i++) {
+        const child = el.children[i] as HTMLElement;
+
+        if (i % expectedSnapGranularity === 0) {
+          expect(child.style.getPropertyValue('scroll-snap-align')).to.be.equal('');
+        } else {
+          expect(child.style.getPropertyValue('scroll-snap-align')).to.be.equal('none');
+        }
+      }
+    });
+  });
+
+  describe('when `orientation` attribute is provided', () => {
+    describe('and value is `vertical`', () => {
+      it('should make the scrollable along the y-axis', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel orientation="vertical" style="height: 100px">
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+          </sl-carousel>
+        `);
+
+        // Act
+        await el.updateComplete;
+
+        // Assert
+        expect(el.scrollContainer.scrollWidth).to.be.equal(el.scrollContainer.clientWidth);
+        expect(el.scrollContainer.scrollHeight).to.be.greaterThan(el.scrollContainer.clientHeight);
+      });
+    });
+
+    describe('and value is `horizontal`', () => {
+      it('should make the scrollable along the x-axis', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel orientation="horizontal" style="height: 100px">
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+          </sl-carousel>
+        `);
+
+        // Act
+        await el.updateComplete;
+
+        // Assert
+        expect(el.scrollContainer.scrollWidth).to.be.greaterThan(el.scrollContainer.clientWidth);
+        expect(el.scrollContainer.scrollHeight).to.be.equal(el.scrollContainer.clientHeight);
+      });
+    });
+  });
+
+  describe('Navigation controls', () => {
+    describe('when the user clicks the next button', () => {
+      it('should scroll to the next slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel navigation>
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+        const nextButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--next')!;
+        sinon.stub(el, 'next');
+
+        await el.updateComplete;
+
+        // Act
+        await clickOnElement(nextButton);
+        await el.updateComplete;
+
+        // Assert
+        expect(el.next).to.have.been.calledOnce;
+      });
+
+      describe('and carousel is positioned on the last slide', () => {
+        it('should not scroll', async () => {
+          // Arrange
+          const el = await fixture<SlCarousel>(html`
+            <sl-carousel navigation>
+              <sl-carousel-item>Node 1</sl-carousel-item>
+              <sl-carousel-item>Node 2</sl-carousel-item>
+              <sl-carousel-item>Node 3</sl-carousel-item>
+            </sl-carousel>
+          `);
+          const nextButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--next')!;
+          sinon.stub(el, 'next');
+
+          el.goToSlide(2, 'auto');
+          await oneEvent(el.scrollContainer, 'scrollend');
+          await el.updateComplete;
+
+          // Act
+          await clickOnElement(nextButton);
+          await el.updateComplete;
+
+          // Assert
+          expect(nextButton).to.have.attribute('aria-disabled', 'true');
+          expect(el.next).not.to.have.been.called;
+        });
+
+        describe('and `loop` attribute is provided', () => {
+          it('should scroll to the first slide', async () => {
+            // Arrange
+            const el = await fixture<SlCarousel>(html`
+              <sl-carousel navigation loop>
+                <sl-carousel-item>Node 1</sl-carousel-item>
+                <sl-carousel-item>Node 2</sl-carousel-item>
+                <sl-carousel-item>Node 3</sl-carousel-item>
+              </sl-carousel>
+            `);
+            const nextButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--next')!;
+
+            el.goToSlide(2, 'auto');
+            await oneEvent(el.scrollContainer, 'scrollend');
+            await el.updateComplete;
+
+            // Act
+            await clickOnElement(nextButton);
+
+            // wait first scroll to clone
+            await oneEvent(el.scrollContainer, 'scrollend');
+            // wait scroll to actual item
+            await oneEvent(el.scrollContainer, 'scrollend');
+
+            // Assert
+            expect(nextButton).to.have.attribute('aria-disabled', 'false');
+            expect(el.activeSlide).to.be.equal(0);
+          });
+        });
+      });
+    });
+
+    describe('and clicks the previous button', () => {
+      it('should scroll to the previous slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel navigation>
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+
+        // Go to the second slide so that the previous button will be enabled
+        el.goToSlide(1, 'auto');
+        await oneEvent(el.scrollContainer, 'scrollend');
+        await el.updateComplete;
+
+        const previousButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--previous')!;
+        sinon.stub(el, 'previous');
+
+        await el.updateComplete;
+
+        // Act
+        await clickOnElement(previousButton);
+        await el.updateComplete;
+
+        // Assert
+        expect(el.previous).to.have.been.calledOnce;
+      });
+
+      describe('and carousel is positioned on the first slide', () => {
+        it('should not scroll', async () => {
+          // Arrange
+          const el = await fixture<SlCarousel>(html`
+            <sl-carousel navigation>
+              <sl-carousel-item>Node 1</sl-carousel-item>
+              <sl-carousel-item>Node 2</sl-carousel-item>
+              <sl-carousel-item>Node 3</sl-carousel-item>
+            </sl-carousel>
+          `);
+
+          const previousButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--previous')!;
+          sinon.stub(el, 'previous');
+          await el.updateComplete;
+
+          // Act
+          await clickOnElement(previousButton);
+          await el.updateComplete;
+
+          // Assert
+          expect(previousButton).to.have.attribute('aria-disabled', 'true');
+          expect(el.previous).not.to.have.been.called;
+        });
+
+        describe('and `loop` attribute is provided', () => {
+          it('should scroll to the last slide', async () => {
+            // Arrange
+            const el = await fixture<SlCarousel>(html`
+              <sl-carousel navigation loop>
+                <sl-carousel-item>Node 1</sl-carousel-item>
+                <sl-carousel-item>Node 2</sl-carousel-item>
+                <sl-carousel-item>Node 3</sl-carousel-item>
+              </sl-carousel>
+            `);
+
+            const previousButton: HTMLElement = el.shadowRoot!.querySelector('.carousel__navigation-button--previous')!;
+            await el.updateComplete;
+
+            // Act
+            await clickOnElement(previousButton);
+
+            // wait first scroll to clone
+            await oneEvent(el.scrollContainer, 'scrollend');
+            // wait scroll to actual item
+            await oneEvent(el.scrollContainer, 'scrollend');
+
+            // Assert
+            expect(previousButton).to.have.attribute('aria-disabled', 'false');
+            expect(el.activeSlide).to.be.equal(2);
+          });
+        });
+      });
+    });
+  });
+
+  describe('API', () => {
+    describe('#next', () => {
+      it('should scroll the carousel to the next slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel slides-per-move="2">
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+        sinon.stub(el, 'goToSlide');
+        await el.updateComplete;
+
+        // Act
+        el.next();
+
+        expect(el.goToSlide).to.have.been.calledWith(2);
+      });
+    });
+
+    describe('#previous', () => {
+      it('should scroll the carousel to the previous slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel slides-per-move="2">
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+        sinon.stub(el, 'goToSlide');
+        await el.updateComplete;
+
+        // Act
+        el.previous();
+
+        expect(el.goToSlide).to.have.been.calledWith(-2);
+      });
+    });
+
+    describe('#goToSlide', () => {
+      it('should scroll the carousel to the nth slide', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel>
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+        await el.updateComplete;
+
+        // Act
+        el.goToSlide(2);
+        await oneEvent(el.scrollContainer, 'scrollend');
+        await el.updateComplete;
+
+        // Assert
+        expect(el.activeSlide).to.be.equal(2);
+      });
+    });
+  });
+
+  describe('Accessibility', () => {
+    it('should pass accessibility tests', async () => {
+      // Arrange
+      const el = await fixture<SlCarousel>(html`
+        <sl-carousel navigation pagination>
+          <sl-carousel-item>Node 1</sl-carousel-item>
+          <sl-carousel-item>Node 2</sl-carousel-item>
+          <sl-carousel-item>Node 3</sl-carousel-item>
+        </sl-carousel>
+      `);
+      const pagination = el.shadowRoot!.querySelector('.carousel__pagination')!;
+      const navigation = el.shadowRoot!.querySelector('.carousel__navigation')!;
+      await el.updateComplete;
+
+      // Assert
+      expect(el.scrollContainer).to.have.attribute('aria-busy', 'false');
+      expect(el.scrollContainer).to.have.attribute('aria-atomic', 'true');
+
+      expect(pagination).to.have.attribute('role', 'tablist');
+      expect(pagination).to.have.attribute('aria-controls', el.scrollContainer.id);
+      for (const paginationItem of pagination.querySelectorAll('.carousel__pagination-item')) {
+        expect(paginationItem).to.have.attribute('role', 'tab');
+        expect(paginationItem).to.have.attribute('aria-selected');
+        expect(paginationItem).to.have.attribute('aria-label');
+      }
+
+      for (const navigationItem of navigation.querySelectorAll('.carousel__navigation-item')) {
+        expect(navigationItem).to.have.attribute('aria-controls', el.scrollContainer.id);
+        expect(navigationItem).to.have.attribute('aria-disabled');
+        expect(navigationItem).to.have.attribute('aria-label');
+      }
+
+      await expect(el).to.be.accessible();
+    });
+
+    describe('when scrolling', () => {
+      it('should update aria-busy attribute', async () => {
+        // Arrange
+        const el = await fixture<SlCarousel>(html`
+          <sl-carousel autoplay>
+            <sl-carousel-item>Node 1</sl-carousel-item>
+            <sl-carousel-item>Node 2</sl-carousel-item>
+            <sl-carousel-item>Node 3</sl-carousel-item>
+          </sl-carousel>
+        `);
+
+        await el.updateComplete;
+
+        // Act
+        el.goToSlide(2, 'smooth');
+        await oneEvent(el.scrollContainer, 'scroll');
+        await el.updateComplete;
+
+        // Assert
+        expect(el.scrollContainer).to.have.attribute('aria-busy', 'true');
+
+        await oneEvent(el.scrollContainer, 'scrollend');
+        await el.updateComplete;
+        expect(el.scrollContainer).to.have.attribute('aria-busy', 'false');
+      });
+    });
+  });
+});

src/components/carousel/carousel.ts

@@ -0,0 +1,471 @@
+import '../icon/icon';
+import { AutoplayController } from './autoplay-controller';
+import { clamp } from 'src/internal/math';
+import { classMap } from 'lit/directives/class-map.js';
+import { customElement, property, query, state } from 'lit/decorators.js';
+import { html } from 'lit';
+import { LocalizeController } from '@shoelace-style/localize';
+import { map } from 'lit/directives/map.js';
+import { prefersReducedMotion } from '../../internal/animate';
+import { range } from 'lit/directives/range.js';
+import { ScrollController } from './scroll-controller';
+import { watch } from '../../internal/watch';
+import ShoelaceElement from '../../internal/shoelace-element';
+import SlCarouselItem from '../carousel-item/carousel-item';
+import styles from './carousel.styles';
+import type { CSSResultGroup } from 'lit';
+
+/**
+ * @summary Carousels display an arbitrary number of content slides along a horizontal or vertical axis.
+ *
+ * @since 2.2
+ * @status experimental
+ *
+ * @dependency sl-icon
+ *
+ * @event {{ index: number, slide: SlCarouselItem }} sl-slide-change - Emitted when the active slide changes.
+ *
+ * @slot - The carousel's main content, one or more `<sl-carousel-item>` elements.
+ * @slot next-icon - Optional next icon to use instead of the default. Works best with `<sl-icon>`.
+ * @slot previous-icon - Optional previous icon to use instead of the default. Works best with `<sl-icon>`.
+ *
+ * @csspart base - The carousel's internal wrapper.
+ * @csspart scroll-container - The scroll container that wraps the slides.
+ * @csspart pagination - The pagination indicators wrapper.
+ * @csspart pagination-item - The pagination indicator.
+ * @csspart pagination-item--active - Applied when the item is active.
+ * @csspart navigation - The navigation wrapper.
+ * @csspart navigation-button - The navigation button.
+ * @csspart navigation-button--previous - Applied to the previous button.
+ * @csspart navigation-button--next - Applied to the next button.
+ *
+ * @cssproperty --slide-gap - The space between each slide.
+ * @cssproperty --aspect-ratio - The aspect ratio of each slide.
+ * @cssproperty --scroll-hint - The amount of padding to apply to the scroll area, allowing adjacent slides to become
+ *  partially visible as a scroll hint.
+ */
+@customElement('sl-carousel')
+export default class SlCarousel extends ShoelaceElement {
+  static styles: CSSResultGroup = styles;
+
+  /** When set, allows the user to navigate the carousel in the same direction indefinitely. */
+  @property({ type: Boolean, reflect: true }) loop = false;
+
+  /** When set, show the carousel's navigation. */
+  @property({ type: Boolean, reflect: true }) navigation = false;
+
+  /** When set, show the carousel's pagination indicators. */
+  @property({ type: Boolean, reflect: true }) pagination = false;
+
+  /** When set, the slides will scroll automatically when the user is not interacting with them.  */
+  @property({ type: Boolean, reflect: true }) autoplay = false;
+
+  /** Specifies the amount of time, in milliseconds, between each automatic scroll.  */
+  @property({ type: Number, attribute: 'autoplay-interval' }) autoplayInterval = 3000;
+
+  /** Specifies how many slides should be shown at a given time.  */
+  @property({ type: Number, attribute: 'slides-per-page' }) slidesPerPage = 1;
+
+  /**
+   * Specifies the number of slides the carousel will advance when scrolling, useful when specifying a `slides-per-page`
+   * greater than one.
+   */
+  @property({ type: Number, attribute: 'slides-per-move' }) slidesPerMove = 1;
+
+  /** Specifies the orientation in which the carousel will lay out.  */
+  @property() orientation: 'horizontal' | 'vertical' = 'horizontal';
+
+  /** When set, it is possible to scroll through the slides by dragging them with the mouse. */
+  @property({ type: Boolean, reflect: true, attribute: 'mouse-dragging' }) mouseDragging = false;
+
+  @query('slot:not([name])') defaultSlot: HTMLSlotElement;
+  @query('.carousel__slides') scrollContainer: HTMLElement;
+  @query('.carousel__pagination') paginationContainer: HTMLElement;
+
+  // The index of the active slide
+  @state() activeSlide = 0;
+
+  private autoplayController = new AutoplayController(this, () => this.next());
+  private scrollController = new ScrollController(this);
+  private readonly slides = this.getElementsByTagName('sl-carousel-item');
+  private intersectionObserver: IntersectionObserver; // determines which slide is displayed
+  // A map containing the state of all the slides
+  private readonly intersectionObserverEntries = new Map<Element, IntersectionObserverEntry>();
+  private readonly localize = new LocalizeController(this);
+  private mutationObserver: MutationObserver;
+
+  connectedCallback(): void {
+    super.connectedCallback();
+    this.setAttribute('role', 'region');
+    this.setAttribute('aria-label', this.localize.term('carousel'));
+
+    const intersectionObserver = new IntersectionObserver(
+      (entries: IntersectionObserverEntry[]) => {
+        entries.forEach(entry => {
+          // Store all the entries in a map to be processed when scrolling ends
+          this.intersectionObserverEntries.set(entry.target, entry);
+
+          const slide = entry.target;
+          slide.toggleAttribute('inert', !entry.isIntersecting);
+          slide.classList.toggle('--in-view', entry.isIntersecting);
+          slide.setAttribute('aria-hidden', entry.isIntersecting ? 'false' : 'true');
+        });
+      },
+      {
+        root: this,
+        threshold: 0.6
+      }
+    );
+    this.intersectionObserver = intersectionObserver;
+
+    // Store the initial state of each slide
+    intersectionObserver.takeRecords().forEach(entry => {
+      this.intersectionObserverEntries.set(entry.target, entry);
+    });
+  }
+
+  disconnectedCallback(): void {
+    super.disconnectedCallback();
+    this.intersectionObserver.disconnect();
+    this.mutationObserver.disconnect();
+  }
+
+  protected firstUpdated(): void {
+    this.initializeSlides();
+    this.mutationObserver = new MutationObserver(this.handleSlotChange.bind(this));
+    this.mutationObserver.observe(this, { childList: true, subtree: false });
+  }
+
+  private getPageCount() {
+    return Math.ceil(this.getSlides().length / this.slidesPerPage);
+  }
+
+  private getCurrentPage() {
+    return Math.floor(this.activeSlide / this.slidesPerPage);
+  }
+
+  private getSlides({ excludeClones = true }: { excludeClones?: boolean } = {}) {
+    return [...this.slides].filter(slide => !excludeClones || !slide.hasAttribute('data-clone'));
+  }
+
+  private handleKeyDown(event: KeyboardEvent) {
+    if (['ArrowLeft', 'ArrowRight', 'ArrowUp', 'ArrowDown', 'Home', 'End'].includes(event.key)) {
+      const target = event.target as HTMLElement;
+      const isRtl = this.localize.dir() === 'rtl';
+      const isFocusInPagination = target.closest('[part~="pagination-item"]') !== null;
+      const isNext =
+        event.key === 'ArrowDown' || (!isRtl && event.key === 'ArrowRight') || (isRtl && event.key === 'ArrowLeft');
+      const isPrevious =
+        event.key === 'ArrowUp' || (!isRtl && event.key === 'ArrowLeft') || (isRtl && event.key === 'ArrowRight');
+
+      event.preventDefault();
+
+      if (isPrevious) {
+        this.previous();
+      }
+
+      if (isNext) {
+        this.next();
+      }
+
+      if (event.key === 'Home') {
+        this.goToSlide(0);
+      }
+
+      if (event.key === 'End') {
+        this.goToSlide(this.getSlides().length - 1);
+      }
+
+      if (isFocusInPagination) {
+        this.updateComplete.then(() => {
+          const activePaginationItem = this.shadowRoot?.querySelector<HTMLButtonElement>(
+            '[part~="pagination-item--active"]'
+          );
+
+          if (activePaginationItem) {
+            activePaginationItem.focus();
+          }
+        });
+      }
+    }
+  }
+
+  private handleScrollEnd() {
+    const slides = this.getSlides();
+    const entries = [...this.intersectionObserverEntries.values()];
+
+    const firstIntersecting: IntersectionObserverEntry | undefined = entries.find(entry => entry.isIntersecting);
+
+    if (this.loop && firstIntersecting?.target.hasAttribute('data-clone')) {
+      const clonePosition = Number(firstIntersecting.target.getAttribute('data-clone'));
+
+      // Scrolls to the original slide without animating, so the user won't notice that the position has changed
+      this.goToSlide(clonePosition, 'auto');
+
+      return;
+    }
+
+    // Activate the first intersecting slide
+    if (firstIntersecting) {
+      this.activeSlide = slides.indexOf(firstIntersecting.target as SlCarouselItem);
+    }
+  }
+
+  private handleSlotChange(mutations: MutationRecord[]) {
+    const needsInitialization = mutations.some(mutation =>
+      [...mutation.addedNodes, ...mutation.removedNodes].some(
+        node => SlCarouselItem.isCarouselItem(node) && !(node as HTMLElement).hasAttribute('data-clone')
+      )
+    );
+
+    // Reinitialize the carousel if a carousel item has been added or removed
+    if (needsInitialization) {
+      this.initializeSlides();
+    }
+    this.requestUpdate();
+  }
+
+  @watch('loop', { waitUntilFirstUpdate: true })
+  @watch('slidesPerPage', { waitUntilFirstUpdate: true })
+  initializeSlides() {
+    const slides = this.getSlides();
+    const intersectionObserver = this.intersectionObserver;
+
+    this.intersectionObserverEntries.clear();
+
+    // Removes all the cloned elements from the carousel
+    this.getSlides({ excludeClones: false }).forEach((slide, index) => {
+      intersectionObserver.unobserve(slide);
+
+      slide.classList.remove('--in-view');
+      slide.classList.remove('--is-active');
+      slide.setAttribute('aria-label', this.localize.term('slideNum', index + 1));
+
+      if (slide.hasAttribute('data-clone')) {
+        slide.remove();
+      }
+    });
+
+    if (this.loop) {
+      // Creates clones to be placed before and after the original elements to simulate infinite scrolling
+      const slidesPerPage = this.slidesPerPage;
+      const lastSlides = slides.slice(-slidesPerPage);
+      const firstSlides = slides.slice(0, slidesPerPage);
+
+      lastSlides.reverse().forEach((slide, i) => {
+        const clone = slide.cloneNode(true) as HTMLElement;
+        clone.setAttribute('data-clone', String(slides.length - i - 1));
+        this.prepend(clone);
+      });
+
+      firstSlides.forEach((slide, i) => {
+        const clone = slide.cloneNode(true) as HTMLElement;
+        clone.setAttribute('data-clone', String(i));
+        this.append(clone);
+      });
+    }
+
+    this.getSlides({ excludeClones: false }).forEach(slide => {
+      intersectionObserver.observe(slide);
+    });
+
+    // Because the DOM may be changed, restore the scroll position to the active slide
+    this.goToSlide(this.activeSlide, 'auto');
+  }
+
+  @watch('activeSlide')
+  handelSlideChange() {
+    const slides = this.getSlides();
+    slides.forEach((slide, i) => {
+      slide.classList.toggle('--is-active', i === this.activeSlide);
+    });
+
+    // Do not emit an event on first render
+    if (this.hasUpdated) {
+      this.emit('sl-slide-change', {
+        detail: {
+          index: this.activeSlide,
+          slide: slides[this.activeSlide]
+        }
+      });
+    }
+  }
+
+  @watch('slidesPerMove')
+  handleSlidesPerMoveChange() {
+    const slides = this.getSlides({ excludeClones: false });
+
+    const slidesPerMove = this.slidesPerMove;
+    slides.forEach((slide, i) => {
+      const shouldSnap = Math.abs(i - slidesPerMove) % slidesPerMove === 0;
+      if (shouldSnap) {
+        slide.style.removeProperty('scroll-snap-align');
+      } else {
+        slide.style.setProperty('scroll-snap-align', 'none');
+      }
+    });
+  }
+
+  @watch('autoplay')
+  handleAutoplayChange() {
+    this.autoplayController.stop();
+    if (this.autoplay) {
+      this.autoplayController.start(this.autoplayInterval);
+    }
+  }
+
+  @watch('mouseDragging')
+  handleMouseDraggingChange() {
+    this.scrollController.mouseDragging = this.mouseDragging;
+  }
+
+  /**
+   * Move the carousel backward by `slides-per-move` slides.
+   *
+   * @param behavior - The behavior used for scrolling.
+   */
+  previous(behavior: ScrollBehavior = 'smooth') {
+    this.goToSlide(this.activeSlide - this.slidesPerMove, behavior);
+  }
+
+  /**
+   * Move the carousel forward by `slides-per-move` slides.
+   *
+   * @param behavior - The behavior used for scrolling.
+   */
+  next(behavior: ScrollBehavior = 'smooth') {
+    this.goToSlide(this.activeSlide + this.slidesPerMove, behavior);
+  }
+
+  /**
+   * Scrolls the carousel to the slide specified by `index`.
+   *
+   * @param index - The slide index.
+   * @param behavior - The behavior used for scrolling.
+   */
+  goToSlide(index: number, behavior: ScrollBehavior = 'smooth') {
+    const { slidesPerPage, loop, scrollContainer } = this;
+
+    const slides = this.getSlides();
+    const slidesWithClones = this.getSlides({ excludeClones: false });
+
+    // Sets the next index without taking into account clones, if any.
+    const newActiveSlide = (index + slides.length) % slides.length;
+    this.activeSlide = newActiveSlide;
+
+    // Get the index of the next slide. For looping carousel it adds `slidesPerPage`
+    // to normalize the starting index in order to ignore the first nth clones.
+    const nextSlideIndex = clamp(index + (loop ? slidesPerPage : 0), 0, slidesWithClones.length - 1);
+    const nextSlide = slidesWithClones[nextSlideIndex];
+
+    const scrollContainerRect = scrollContainer.getBoundingClientRect();
+    const nextSlideRect = nextSlide.getBoundingClientRect();
+
+    scrollContainer.scrollTo({
+      left: nextSlideRect.left - scrollContainerRect.left + scrollContainer.scrollLeft,
+      top: nextSlideRect.top - scrollContainerRect.top + scrollContainer.scrollTop,
+      behavior: prefersReducedMotion() ? 'auto' : behavior
+    });
+  }
+
+  render() {
+    const { scrollController, slidesPerPage } = this;
+    const pagesCount = this.getPageCount();
+    const currentPage = this.getCurrentPage();
+    const prevEnabled = this.loop || currentPage > 0;
+    const nextEnabled = this.loop || currentPage < pagesCount - 1;
+    const isLtr = this.localize.dir() === 'ltr';
+
+    return html`
+      <div part="base" class="carousel">
+        <div
+          id="scroll-container"
+          part="scroll-container"
+          class="${classMap({
+            carousel__slides: true,
+            'carousel__slides--horizontal': this.orientation === 'horizontal',
+            'carousel__slides--vertical': this.orientation === 'vertical'
+          })}"
+          style="--slides-per-page: ${this.slidesPerPage};"
+          aria-busy="${scrollController.scrolling ? 'true' : 'false'}"
+          aria-atomic="true"
+          tabindex="0"
+          @keydown=${this.handleKeyDown}
+          @scrollend=${this.handleScrollEnd}
+        >
+          <slot></slot>
+        </div>
+
+        ${this.navigation
+          ? html`
+              <div part="navigation" class="carousel__navigation">
+                <button
+                  part="navigation-button navigation-button--previous"
+                  class="${classMap({
+                    'carousel__navigation-button': true,
+                    'carousel__navigation-button--previous': true,
+                    'carousel__navigation-button--disabled': !prevEnabled
+                  })}"
+                  aria-label="${this.localize.term('previousSlide')}"
+                  aria-controls="scroll-container"
+                  aria-disabled="${prevEnabled ? 'false' : 'true'}"
+                  @click=${prevEnabled ? () => this.previous() : null}
+                >
+                  <slot name="previous-icon">
+                    <sl-icon library="system" name="${isLtr ? 'chevron-left' : 'chevron-right'}"></sl-icon>
+                  </slot>
+                </button>
+
+                <button
+                  part="navigation-button navigation-button--next"
+                  class=${classMap({
+                    'carousel__navigation-button': true,
+                    'carousel__navigation-button--next': true,
+                    'carousel__navigation-button--disabled': !nextEnabled
+                  })}
+                  aria-label="${this.localize.term('nextSlide')}"
+                  aria-controls="scroll-container"
+                  aria-disabled="${nextEnabled ? 'false' : 'true'}"
+                  @click=${nextEnabled ? () => this.next() : null}
+                >
+                  <slot name="next-icon">
+                    <sl-icon library="system" name="${isLtr ? 'chevron-right' : 'chevron-left'}"></sl-icon>
+                  </slot>
+                </button>
+              </div>
+            `
+          : ''}
+        ${this.pagination
+          ? html`
+              <div part="pagination" role="tablist" class="carousel__pagination" aria-controls="scroll-container">
+                ${map(range(pagesCount), index => {
+                  const isActive = index === currentPage;
+                  return html`
+                    <button
+                      part="pagination-item ${isActive ? 'pagination-item--active' : ''}"
+                      class="${classMap({
+                        'carousel__pagination-item': true,
+                        'carousel__pagination-item--active': isActive
+                      })}"
+                      role="tab"
+                      aria-selected="${isActive ? 'true' : 'false'}"
+                      aria-label="${this.localize.term('goToSlide', index + 1, pagesCount)}"
+                      tabindex=${isActive ? '0' : '-1'}
+                      @click=${() => this.goToSlide(index * slidesPerPage)}
+                      @keydown=${this.handleKeyDown}
+                    ></button>
+                  `;
+                })}
+              </div>
+            `
+          : ''}
+      </div>
+    `;
+  }
+}
+
+declare global {
+  interface HTMLElementTagNameMap {
+    'sl-carousel': SlCarousel;
+  }
+}

src/components/carousel/scroll-controller.ts

@@ -0,0 +1,178 @@
+import { debounce } from 'src/internal/debounce';
+import { prefersReducedMotion } from 'src/internal/animate';
+import { waitForEvent } from 'src/internal/event';
+import type { ReactiveController, ReactiveElement } from 'lit';
+
+interface ScrollHost extends ReactiveElement {
+  scrollContainer: HTMLElement;
+}
+
+/**
+ * A controller for handling scrolling and mouse dragging.
+ */
+export class ScrollController<T extends ScrollHost> implements ReactiveController {
+  private host: T;
+  private pointers = new Set();
+
+  dragging = false;
+  scrolling = false;
+  mouseDragging = false;
+
+  constructor(host: T) {
+    this.host = host;
+
+    host.addController(this);
+
+    this.handleScroll = this.handleScroll.bind(this);
+    this.handlePointerDown = this.handlePointerDown.bind(this);
+    this.handlePointerMove = this.handlePointerMove.bind(this);
+    this.handlePointerUp = this.handlePointerUp.bind(this);
+    this.handlePointerUp = this.handlePointerUp.bind(this);
+    this.handleTouchStart = this.handleTouchStart.bind(this);
+    this.handleTouchEnd = this.handleTouchEnd.bind(this);
+  }
+
+  async hostConnected() {
+    const host = this.host;
+    await host.updateComplete;
+
+    const scrollContainer = host.scrollContainer;
+
+    scrollContainer.addEventListener('scroll', this.handleScroll, { passive: true });
+    scrollContainer.addEventListener('pointerdown', this.handlePointerDown);
+    scrollContainer.addEventListener('pointerup', this.handlePointerUp);
+    scrollContainer.addEventListener('pointercancel', this.handlePointerUp);
+    scrollContainer.addEventListener('touchstart', this.handleTouchStart, { passive: true });
+    scrollContainer.addEventListener('touchend', this.handleTouchEnd);
+  }
+
+  hostDisconnected(): void {
+    const host = this.host;
+    const scrollContainer = host.scrollContainer;
+
+    scrollContainer.removeEventListener('scroll', this.handleScroll);
+    scrollContainer.removeEventListener('pointerdown', this.handlePointerDown);
+    scrollContainer.removeEventListener('pointerup', this.handlePointerUp);
+    scrollContainer.removeEventListener('pointercancel', this.handlePointerUp);
+    scrollContainer.removeEventListener('touchstart', this.handleTouchStart);
+    scrollContainer.removeEventListener('touchend', this.handleTouchEnd);
+  }
+
+  handleScroll() {
+    if (!this.scrolling) {
+      this.scrolling = true;
+      this.host.requestUpdate();
+    }
+    this.handleScrollEnd();
+  }
+
+  @debounce(100)
+  handleScrollEnd() {
+    if (!this.pointers.size) {
+      // If no pointer is active in the scroll area then the scroll has ended
+      this.scrolling = false;
+      this.host.scrollContainer.dispatchEvent(
+        new CustomEvent('scrollend', {
+          bubbles: false,
+          cancelable: false
+        })
+      );
+      this.host.requestUpdate();
+    } else {
+      // otherwise let's wait a bit more
+      this.handleScrollEnd();
+    }
+  }
+
+  handlePointerDown(event: PointerEvent) {
+    if (event.pointerType === 'touch') {
+      return;
+    }
+
+    this.pointers.add(event.pointerId);
+
+    const canDrag = this.mouseDragging && !this.dragging && event.button === 0;
+    if (canDrag) {
+      event.preventDefault();
+
+      this.host.scrollContainer.addEventListener('pointermove', this.handlePointerMove);
+    }
+  }
+
+  handlePointerMove(event: PointerEvent) {
+    const scrollContainer = this.host.scrollContainer;
+
+    const hasMoved = !!event.movementX || !!event.movementY;
+    if (!this.dragging && hasMoved) {
+      // Start dragging if it hasn't yet
+      scrollContainer.setPointerCapture(event.pointerId);
+      this.handleDragStart();
+    } else if (scrollContainer.hasPointerCapture(event.pointerId)) {
+      // Ignore pointers that we are not tracking
+      this.handleDrag(event);
+    }
+  }
+
+  handlePointerUp(event: PointerEvent) {
+    this.pointers.delete(event.pointerId);
+    this.host.scrollContainer.releasePointerCapture(event.pointerId);
+
+    if (this.pointers.size === 0) {
+      this.handleDragEnd();
+    }
+  }
+
+  handleTouchEnd(event: TouchEvent) {
+    for (const touch of event.changedTouches) {
+      this.pointers.delete(touch.identifier);
+    }
+  }
+
+  handleTouchStart(event: TouchEvent) {
+    for (const touch of event.touches) {
+      this.pointers.add(touch.identifier);
+    }
+  }
+
+  handleDragStart() {
+    const host = this.host;
+
+    this.dragging = true;
+    host.scrollContainer.style.setProperty('scroll-snap-type', 'unset');
+    host.requestUpdate();
+  }
+
+  handleDrag(event: PointerEvent) {
+    this.host.scrollContainer.scrollBy({
+      left: -event.movementX,
+      top: -event.movementY
+    });
+  }
+
+  async handleDragEnd() {
+    const host = this.host;
+    const scrollContainer = host.scrollContainer;
+
+    scrollContainer.removeEventListener('pointermove', this.handlePointerMove);
+    this.dragging = false;
+
+    const startLeft = scrollContainer.scrollLeft;
+    const startTop = scrollContainer.scrollTop;
+
+    scrollContainer.style.removeProperty('scroll-snap-type');
+    const finalLeft = scrollContainer.scrollLeft;
+    const finalTop = scrollContainer.scrollTop;
+
+    scrollContainer.style.setProperty('scroll-snap-type', 'unset');
+    scrollContainer.scrollTo({ left: startLeft, top: startTop, behavior: 'auto' });
+    scrollContainer.scrollTo({ left: finalLeft, top: finalTop, behavior: prefersReducedMotion() ? 'auto' : 'smooth' });
+
+    if (this.scrolling) {
+      await waitForEvent(scrollContainer, 'scrollend');
+    }
+
+    scrollContainer.style.removeProperty('scroll-snap-type');
+
+    host.requestUpdate();
+  }
+}

src/components/checkbox/checkbox.styles.ts

@@ -11,7 +11,7 @@ export default css`
   .checkbox {
     position: relative;
     display: inline-flex;
-    align-items: top;
+    align-items: flex-start;
     font-family: var(--sl-input-font-family);
     font-weight: var(--sl-input-font-weight);
     color: var(--sl-input-label-color);

src/components/checkbox/checkbox.ts

@@ -158,6 +158,11 @@ export default class SlCheckbox extends ShoelaceElement implements ShoelaceFormC
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.input.reportValidity();

src/components/color-picker/color-picker.test.ts

@@ -493,20 +493,22 @@ describe('<sl-color-picker>', () => {
       expect(el.checkValidity()).to.be.true;
     });
 
-    it.skip('should be invalid when required and empty', async () => {
+    it('should be invalid when required and empty', async () => {
       const el = await fixture<SlColorPicker>(html` <sl-color-picker required></sl-color-picker> `);
       expect(el.checkValidity()).to.be.false;
     });
 
-    it.skip('should be invalid when required and disabled is removed', async () => {
+    it('should be invalid when required and disabled is removed', async () => {
       const el = await fixture<SlColorPicker>(html` <sl-color-picker disabled required></sl-color-picker> `);
       el.disabled = false;
       await el.updateComplete;
       expect(el.checkValidity()).to.be.false;
     });
 
-    it.skip('should receive the correct validation attributes ("states") when valid', async () => {
-      const el = await fixture<SlColorPicker>(html` <sl-color-picker required value="a"></sl-color-picker> `);
+    it('should receive the correct validation attributes ("states") when valid', async () => {
+      const el = await fixture<SlColorPicker>(html` <sl-color-picker required value="#fff"></sl-color-picker> `);
+      const trigger = el.shadowRoot!.querySelector('[part~="trigger"]')!;
+      const grid = el.shadowRoot!.querySelector('[part~="grid"]')!;
 
       expect(el.checkValidity()).to.be.true;
       expect(el.hasAttribute('data-required')).to.be.true;
@@ -516,18 +518,20 @@ describe('<sl-color-picker>', () => {
       expect(el.hasAttribute('data-user-invalid')).to.be.false;
       expect(el.hasAttribute('data-user-valid')).to.be.false;
 
-      // // TODO simulate user interaction
-      // el.focus();
-      // await sendKeys({ press: 'b' });
-      // await el.updateComplete;
+      await clickOnElement(trigger);
+      await aTimeout(500);
+      await clickOnElement(grid);
+      await el.updateComplete;
 
-      // expect(el.checkValidity()).to.be.true;
-      // expect(el.hasAttribute('data-user-invalid')).to.be.false;
-      // expect(el.hasAttribute('data-user-valid')).to.be.true;
+      expect(el.checkValidity()).to.be.true;
+      expect(el.hasAttribute('data-user-invalid')).to.be.false;
+      expect(el.hasAttribute('data-user-valid')).to.be.true;
     });
 
-    it.skip('should receive the correct validation attributes ("states") when invalid', async () => {
+    it('should receive the correct validation attributes ("states") when invalid', async () => {
       const el = await fixture<SlColorPicker>(html` <sl-color-picker required></sl-color-picker> `);
+      const trigger = el.shadowRoot!.querySelector('[part~="trigger"]')!;
+      const grid = el.shadowRoot!.querySelector('[part~="grid"]')!;
 
       expect(el.hasAttribute('data-required')).to.be.true;
       expect(el.hasAttribute('data-optional')).to.be.false;
@@ -536,14 +540,14 @@ describe('<sl-color-picker>', () => {
       expect(el.hasAttribute('data-user-invalid')).to.be.false;
       expect(el.hasAttribute('data-user-valid')).to.be.false;
 
-      // // TODO simulate user interaction
-      // el.focus();
-      // await sendKeys({ press: 'a' });
-      // await sendKeys({ press: 'Backspace' });
-      // await el.updateComplete;
+      await clickOnElement(trigger);
+      await aTimeout(500);
+      await clickOnElement(grid);
+      await el.updateComplete;
 
-      // expect(el.hasAttribute('data-user-invalid')).to.be.true;
-      // expect(el.hasAttribute('data-user-valid')).to.be.false;
+      expect(el.checkValidity()).to.be.true;
+      expect(el.hasAttribute('data-user-invalid')).to.be.false;
+      expect(el.hasAttribute('data-user-valid')).to.be.true;
     });
   });
 

src/components/color-picker/color-picker.ts

@@ -20,8 +20,10 @@ import ShoelaceElement from '../../internal/shoelace-element';
 import styles from './color-picker.styles';
 import type { CSSResultGroup } from 'lit';
 import type { ShoelaceFormControl } from '../../internal/shoelace-element';
+import type SlChangeEvent from '../../events/sl-change';
 import type SlDropdown from '../dropdown/dropdown';
 import type SlInput from '../input/input';
+import type SlInputEvent from '../../events/sl-input';
 
 const hasEyeDropper = 'EyeDropper' in window;
 
@@ -417,7 +419,7 @@ export default class SlColorPicker extends ShoelaceElement implements ShoelaceFo
     }
   }
 
-  private handleInputChange(event: CustomEvent) {
+  private handleInputChange(event: SlChangeEvent) {
     const target = event.target as HTMLInputElement;
     const oldValue = this.value;
 
@@ -437,7 +439,7 @@ export default class SlColorPicker extends ShoelaceElement implements ShoelaceFo
     }
   }
 
-  private handleInputInput(event: CustomEvent) {
+  private handleInputInput(event: SlInputEvent) {
     this.formControlController.updateValidity();
 
     // Prevent the <sl-input>'s sl-input event from bubbling up
@@ -762,6 +764,11 @@ export default class SlColorPicker extends ShoelaceElement implements ShoelaceFo
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     if (!this.inline && !this.validity.valid) {

src/components/details/details.test.ts

@@ -2,8 +2,24 @@
 import { expect, fixture, html, waitUntil } from '@open-wc/testing';
 import sinon from 'sinon';
 import type SlDetails from './details';
+import type SlHideEvent from '../../events/sl-hide';
+import type SlShowEvent from '../../events/sl-show';
 
 describe('<sl-details>', () => {
+  describe('accessibility', () => {
+    it('should be accessible when closed', async () => {
+      const details = await fixture<SlDetails>(html`<sl-details summary="Test"> Test text </sl-details>`);
+
+      await expect(details).to.be.accessible();
+    });
+
+    it('should be accessible when open', async () => {
+      const details = await fixture<SlDetails>(html`<sl-details open summary="Test">Test text</sl-details>`);
+
+      await expect(details).to.be.accessible();
+    });
+  });
+
   it('should be visible with the open attribute', async () => {
     const el = await fixture<SlDetails>(html`
       <sl-details open>
@@ -134,7 +150,7 @@ describe('<sl-details>', () => {
         consequat.
       </sl-details>
     `);
-    const showHandler = sinon.spy((event: CustomEvent) => event.preventDefault());
+    const showHandler = sinon.spy((event: SlShowEvent) => event.preventDefault());
 
     el.addEventListener('sl-show', showHandler);
     el.open = true;
@@ -153,7 +169,7 @@ describe('<sl-details>', () => {
         consequat.
       </sl-details>
     `);
-    const hideHandler = sinon.spy((event: CustomEvent) => event.preventDefault());
+    const hideHandler = sinon.spy((event: SlHideEvent) => event.preventDefault());
 
     el.addEventListener('sl-hide', hideHandler);
     el.open = false;

src/components/details/details.ts

@@ -170,7 +170,7 @@ export default class SlDetails extends ShoelaceElement {
           'details--rtl': isRtl
         })}
       >
-        <header
+        <div
           part="header"
           id="header"
           class="details__header"
@@ -192,10 +192,10 @@ export default class SlDetails extends ShoelaceElement {
               <sl-icon library="system" name=${isRtl ? 'chevron-left' : 'chevron-right'}></sl-icon>
             </slot>
           </span>
-        </header>
+        </div>
 
-        <div class="details__body">
-          <slot part="content" id="content" class="details__content" role="region" aria-labelledby="header"></slot>
+        <div class="details__body" role="region" aria-labelledby="header">
+          <slot part="content" id="content" class="details__content"></slot>
         </div>
       </div>
     `;

src/components/dropdown/dropdown.ts

@@ -6,7 +6,6 @@ import { getAnimation, setDefaultAnimation } from '../../utilities/animation-reg
 import { getTabbableBoundary } from '../../internal/tabbable';
 import { html } from 'lit';
 import { LocalizeController } from '../../utilities/localize';
-import { scrollIntoView } from '../../internal/scroll';
 import { waitForEvent } from '../../internal/event';
 import { watch } from '../../internal/watch';
 import ShoelaceElement from '../../internal/shoelace-element';
@@ -15,8 +14,8 @@ import type { CSSResultGroup } from 'lit';
 import type SlButton from '../button/button';
 import type SlIconButton from '../icon-button/icon-button';
 import type SlMenu from '../menu/menu';
-import type SlMenuItem from '../menu-item/menu-item';
 import type SlPopup from '../popup/popup';
+import type SlSelectEvent from '../../events/sl-select';
 
 /**
  * @summary Dropdowns expose additional content that "drops down" in a panel.
@@ -104,7 +103,6 @@ export default class SlDropdown extends ShoelaceElement {
 
   connectedCallback() {
     super.connectedCallback();
-    this.handleMenuItemActivate = this.handleMenuItemActivate.bind(this);
     this.handlePanelSelect = this.handlePanelSelect.bind(this);
     this.handleKeyDown = this.handleKeyDown.bind(this);
     this.handleDocumentKeyDown = this.handleDocumentKeyDown.bind(this);
@@ -201,12 +199,7 @@ export default class SlDropdown extends ShoelaceElement {
     }
   }
 
-  handleMenuItemActivate(event: CustomEvent) {
-    const item = event.target as SlMenuItem;
-    scrollIntoView(item, this.panel);
-  }
-
-  handlePanelSelect(event: CustomEvent) {
+  handlePanelSelect(event: SlSelectEvent) {
     const target = event.target as HTMLElement;
 
     // Hide the dropdown when a menu item is selected
@@ -342,7 +335,6 @@ export default class SlDropdown extends ShoelaceElement {
   }
 
   addOpenListeners() {
-    this.panel.addEventListener('sl-activate', this.handleMenuItemActivate);
     this.panel.addEventListener('sl-select', this.handlePanelSelect);
     this.panel.addEventListener('keydown', this.handleKeyDown);
     document.addEventListener('keydown', this.handleDocumentKeyDown);
@@ -351,7 +343,6 @@ export default class SlDropdown extends ShoelaceElement {
 
   removeOpenListeners() {
     if (this.panel) {
-      this.panel.removeEventListener('sl-activate', this.handleMenuItemActivate);
       this.panel.removeEventListener('sl-select', this.handlePanelSelect);
       this.panel.removeEventListener('keydown', this.handleKeyDown);
     }

src/components/icon/icon.test.ts

@@ -1,6 +1,8 @@
 import { elementUpdated, expect, fixture, html, oneEvent } from '@open-wc/testing';
 import { registerIconLibrary } from '../../../dist/shoelace.js';
+import type SlErrorEvent from '../../events/sl-error';
 import type SlIcon from './icon';
+import type SlLoadEvent from '../../events/sl-load';
 
 const testLibraryIcons = {
   'test-icon1': `
@@ -46,7 +48,7 @@ describe('<sl-icon>', () => {
 
     it('renders pre-loaded system icons and emits sl-load event', async () => {
       const el = await fixture<SlIcon>(html` <sl-icon library="system"></sl-icon> `);
-      const listener = oneEvent(el, 'sl-load') as Promise<CustomEvent>;
+      const listener = oneEvent(el, 'sl-load') as Promise<SlLoadEvent>;
 
       el.name = 'check';
       const ev = await listener;
@@ -93,6 +95,7 @@ describe('<sl-icon>', () => {
       await elementUpdated(el);
 
       expect(el.shadowRoot?.querySelector('svg')).to.exist;
+      expect(el.shadowRoot?.querySelector('svg')?.part.contains('svg')).to.be.true;
       expect(el.shadowRoot?.querySelector('svg')?.getAttribute('id')).to.equal(fakeId);
     });
   });
@@ -100,7 +103,7 @@ describe('<sl-icon>', () => {
   describe('new library', () => {
     it('renders icons from the new library and emits sl-load event', async () => {
       const el = await fixture<SlIcon>(html` <sl-icon library="test-library"></sl-icon> `);
-      const listener = oneEvent(el, 'sl-load') as Promise<CustomEvent>;
+      const listener = oneEvent(el, 'sl-load') as Promise<SlLoadEvent>;
 
       el.name = 'test-icon1';
       const ev = await listener;
@@ -129,7 +132,7 @@ describe('<sl-icon>', () => {
 
     it('emits sl-error when the file cant be retrieved', async () => {
       const el = await fixture<SlIcon>(html` <sl-icon library="test-library"></sl-icon> `);
-      const listener = oneEvent(el, 'sl-error') as Promise<CustomEvent>;
+      const listener = oneEvent(el, 'sl-error') as Promise<SlErrorEvent>;
 
       el.name = 'bad-request';
       const ev = await listener;
@@ -141,7 +144,7 @@ describe('<sl-icon>', () => {
 
     it("emits sl-error when there isn't an svg element in the registered icon", async () => {
       const el = await fixture<SlIcon>(html` <sl-icon library="test-library"></sl-icon> `);
-      const listener = oneEvent(el, 'sl-error') as Promise<CustomEvent>;
+      const listener = oneEvent(el, 'sl-error') as Promise<SlErrorEvent>;
 
       el.name = 'bad-icon';
       const ev = await listener;

src/components/icon/icon.ts

@@ -1,14 +1,16 @@
 import { customElement, property, state } from 'lit/decorators.js';
 import { getIconLibrary, unwatchIcon, watchIcon } from './library';
-import { html } from 'lit';
-import { requestIcon } from './request';
-import { unsafeSVG } from 'lit/directives/unsafe-svg.js';
 import { watch } from '../../internal/watch';
 import ShoelaceElement from '../../internal/shoelace-element';
 import styles from './icon.styles';
 import type { CSSResultGroup } from 'lit';
 
+const CACHEABLE_ERROR = Symbol();
+const RETRYABLE_ERROR = Symbol();
+type SVGResult = SVGSVGElement | typeof RETRYABLE_ERROR | typeof CACHEABLE_ERROR;
+
 let parser: DOMParser;
+const iconCache = new Map<string, Promise<SVGResult>>();
 
 /**
  * @summary Icons are symbols that can be used to represent various options within an application.
@@ -18,12 +20,44 @@ let parser: DOMParser;
  *
  * @event sl-load - Emitted when the icon has loaded.
  * @event sl-error - Emitted when the icon fails to load due to an error.
+ *
+ * @csspart svg - The internal SVG element.
  */
 @customElement('sl-icon')
 export default class SlIcon extends ShoelaceElement {
   static styles: CSSResultGroup = styles;
 
-  @state() private svg = '';
+  /** Given a URL, this function returns the resulting SVG element or an appropriate error symbol. */
+  private static async resolveIcon(url: string): Promise<SVGResult> {
+    let fileData: Response;
+    try {
+      fileData = await fetch(url, { mode: 'cors' });
+      if (!fileData.ok) return fileData.status === 410 ? CACHEABLE_ERROR : RETRYABLE_ERROR;
+    } catch {
+      return RETRYABLE_ERROR;
+    }
+
+    try {
+      const div = document.createElement('div');
+      div.innerHTML = await fileData.text();
+
+      const svg = div.firstElementChild;
+      if (svg?.tagName?.toLowerCase() !== 'svg') return CACHEABLE_ERROR;
+
+      if (!parser) parser = new DOMParser();
+      const doc = parser.parseFromString(svg.outerHTML, 'text/html');
+
+      const svgEl = doc.body.querySelector('svg');
+      if (!svgEl) return CACHEABLE_ERROR;
+
+      svgEl.part.add('svg');
+      return document.adoptNode(svgEl);
+    } catch {
+      return CACHEABLE_ERROR;
+    }
+  }
+
+  @state() private svg: SVGElement | null = null;
 
   /** The name of the icon to draw. Available names depend on the icon library being used. */
   @property({ reflect: true }) name?: string;
@@ -85,45 +119,42 @@ export default class SlIcon extends ShoelaceElement {
     const library = getIconLibrary(this.library);
     const url = this.getUrl();
 
-    // Create an instance of the DOM parser. We do it here instead of top-level to support SSR while maintaining a
-    // single parser instance for optimal performance.
-    if (!parser) {
-      parser = new DOMParser();
+    if (!url) {
+      this.svg = null;
+      return;
     }
 
-    if (url) {
-      try {
-        const file = await requestIcon(url);
-        if (url !== this.getUrl()) {
-          // If the url has changed while fetching the icon, ignore this request
-          return;
-        } else if (file.ok) {
-          const doc = parser.parseFromString(file.svg, 'text/html');
-          const svgEl = doc.body.querySelector('svg');
+    let iconResolver = iconCache.get(url);
+    if (!iconResolver) {
+      iconResolver = SlIcon.resolveIcon(url);
+      iconCache.set(url, iconResolver);
+    }
 
-          if (svgEl !== null) {
-            library?.mutator?.(svgEl);
-            this.svg = svgEl.outerHTML;
-            this.emit('sl-load');
-          } else {
-            this.svg = '';
-            this.emit('sl-error');
-          }
-        } else {
-          this.svg = '';
-          this.emit('sl-error');
-        }
-      } catch {
+    const svg = await iconResolver;
+    if (svg === RETRYABLE_ERROR) {
+      iconCache.delete(url);
+    }
+
+    if (url !== this.getUrl()) {
+      // If the url has changed while fetching the icon, ignore this request
+      return;
+    }
+
+    switch (svg) {
+      case RETRYABLE_ERROR:
+      case CACHEABLE_ERROR:
+        this.svg = null;
         this.emit('sl-error');
-      }
-    } else if (this.svg.length > 0) {
-      // If we can't resolve a URL and an icon was previously set, remove it
-      this.svg = '';
+        break;
+      default:
+        this.svg = svg.cloneNode(true) as SVGElement;
+        library?.mutator?.(this.svg);
+        this.emit('sl-load');
     }
   }
 
   render() {
-    return html` ${unsafeSVG(this.svg)} `;
+    return this.svg;
   }
 }
 

src/components/icon/library.default.ts

@@ -3,7 +3,7 @@ import type { IconLibrary } from './library';
 
 const library: IconLibrary = {
   name: 'default',
-  resolver: name => `${getBasePath()}/assets/icons/${name}.svg`
+  resolver: name => getBasePath(`assets/icons/${name}.svg`)
 };
 
 export default library;

src/components/icon/request.ts

@@ -1,42 +0,0 @@
-import { requestInclude } from '../include/request';
-
-type IconFile =
-  | {
-      ok: true;
-      status: number;
-      svg: string;
-    }
-  | {
-      ok: false;
-      status: number;
-      svg: null;
-    };
-
-interface IconFileUnknown {
-  ok: boolean;
-  status: number;
-  svg: string | null;
-}
-
-const iconFiles = new Map<string, IconFile>();
-
-export async function requestIcon(url: string): Promise<IconFile> {
-  if (iconFiles.has(url)) {
-    return iconFiles.get(url)!;
-  }
-  const fileData = await requestInclude(url);
-  const iconFileData: IconFileUnknown = {
-    ok: fileData.ok,
-    status: fileData.status,
-    svg: null
-  };
-  if (fileData.ok) {
-    const div = document.createElement('div');
-    div.innerHTML = fileData.html;
-    const svg = div.firstElementChild;
-    iconFileData.svg = svg?.tagName.toLowerCase() === 'svg' ? svg.outerHTML : '';
-  }
-
-  iconFiles.set(url, iconFileData as IconFile);
-  return iconFileData as IconFile;
-}

src/components/include/request.ts

@@ -4,20 +4,26 @@ interface IncludeFile {
   html: string;
 }
 
-const includeFiles = new Map<string, Promise<IncludeFile>>();
+const includeFiles = new Map<string, IncludeFile | Promise<IncludeFile>>();
 
 /** Fetches an include file from a remote source. Caching is enabled so the origin is only pinged once. */
 export function requestInclude(src: string, mode: 'cors' | 'no-cors' | 'same-origin' = 'cors'): Promise<IncludeFile> {
-  if (includeFiles.has(src)) {
-    return includeFiles.get(src)!;
+  const prev = includeFiles.get(src);
+  if (prev !== undefined) {
+    // Promise.resolve() transparently unboxes prev if it was a promise.
+    return Promise.resolve(prev);
   }
   const fileDataPromise = fetch(src, { mode: mode }).then(async response => {
-    return {
+    const res = {
       ok: response.ok,
       status: response.status,
       html: await response.text()
     };
+    // Replace the cached promise with its result to avoid having buggy browser Promises retain memory as mentioned in #1284 and #1249
+    includeFiles.set(src, res);
+    return res;
   });
+  // Cache the promise to only fetch() once per src
   includeFiles.set(src, fileDataPromise);
   return fileDataPromise;
 }

src/components/input/input.styles.ts

@@ -281,12 +281,6 @@ export default css`
     display: none;
   }
 
-  /* Hide Firefox's clear button on date and time inputs */
-  .input--is-firefox input[type='date'],
-  .input--is-firefox input[type='time'] {
-    clip-path: inset(0 2em 0 0);
-  }
-
   /* Hide the built-in number spinner */
   .input--no-spin-buttons input[type='number']::-webkit-outer-spin-button,
   .input--no-spin-buttons input[type='number']::-webkit-inner-spin-button {

src/components/input/input.test.ts

@@ -350,7 +350,7 @@ describe('<sl-input>', () => {
       await el.updateComplete;
     });
 
-    it('should not emit sl-change or sl-input when calling setinputText()', async () => {
+    it('should not emit sl-change or sl-input when calling setRangeText()', async () => {
       const el = await fixture<SlInput>(html` <sl-input value="hi there"></sl-input> `);
 
       el.addEventListener('sl-change', () => expect.fail('sl-change should not be emitted'));

src/components/input/input.ts

@@ -14,18 +14,6 @@ import styles from './input.styles';
 import type { CSSResultGroup } from 'lit';
 import type { ShoelaceFormControl } from '../../internal/shoelace-element';
 
-//
-// It's currently impossible to hide Firefox's built-in clear icon when using <input type="date|time">, so we need this
-// check to apply a clip-path to hide it. I know, I know…user agent sniffing is nasty but, if it fails, we only see a
-// redundant clear icon so nothing important is breaking. The benefits outweigh the costs for this one. See the
-// discussion at: https://github.com/shoelace-style/shoelace/pull/794
-//
-// Also note that we do the Chromium check first to prevent Chrome from logging a console notice as described here:
-// https://github.com/shoelace-style/shoelace/issues/855
-//
-const isChromium = navigator.userAgentData?.brands.some(b => b.brand.includes('Chromium'));
-const isFirefox = isChromium ? false : navigator.userAgent.includes('Firefox');
-
 /**
  * @summary Inputs collect data from the user.
  * @documentation https://shoelace.style/components/input
@@ -156,10 +144,10 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
   @property({ type: Number }) maxlength: number;
 
   /** The input's minimum value. Only applies to date and number input types. */
-  @property({ type: Number }) min: number;
+  @property() min: number | string;
 
   /** The input's maximum value. Only applies to date and number input types. */
-  @property({ type: Number }) max: number;
+  @property() max: number | string;
 
   /**
    * Specifies the granularity that the value must adhere to, or the special value `any` which means no stepping is
@@ -202,13 +190,20 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
    */
   @property() inputmode: 'none' | 'text' | 'decimal' | 'numeric' | 'tel' | 'search' | 'email' | 'url';
 
+  //
+  // NOTE: We use an in-memory input for these getters/setters instead of the one in the template because the properties
+  // can be set before the component is rendered.
+  //
+
   /** Gets or sets the current value as a `Date` object. Returns `null` if the value can't be converted. */
   get valueAsDate() {
-    return this.input?.valueAsDate ?? null;
+    const input = document.createElement('input');
+    input.type = 'date';
+    input.value = this.value;
+    return input.valueAsDate;
   }
 
   set valueAsDate(newValue: Date | null) {
-    // We use an in-memory input instead of the one in the template because the property can be set before render
     const input = document.createElement('input');
     input.type = 'date';
     input.valueAsDate = newValue;
@@ -217,11 +212,13 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
 
   /** Gets or sets the current value as a number. Returns `NaN` if the value can't be converted. */
   get valueAsNumber() {
-    return this.input?.valueAsNumber ?? parseFloat(this.value);
+    const input = document.createElement('input');
+    input.type = 'number';
+    input.value = this.value;
+    return input.valueAsNumber;
   }
 
   set valueAsNumber(newValue: number) {
-    // We use an in-memory input instead of the one in the template because the property can be set before render
     const input = document.createElement('input');
     input.type = 'number';
     input.valueAsNumber = newValue;
@@ -389,6 +386,11 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.input.reportValidity();
@@ -447,8 +449,7 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
               'input--disabled': this.disabled,
               'input--focused': this.hasFocus,
               'input--empty': !this.value,
-              'input--no-spin-buttons': this.noSpinButtons,
-              'input--is-firefox': isFirefox
+              'input--no-spin-buttons': this.noSpinButtons
             })}
           >
             <slot name="prefix" part="prefix" class="input__prefix"></slot>
@@ -469,9 +470,9 @@ export default class SlInput extends ShoelaceElement implements ShoelaceFormCont
               max=${ifDefined(this.max)}
               step=${ifDefined(this.step as number)}
               .value=${live(this.value)}
-              autocapitalize=${ifDefined(this.type === 'password' ? 'off' : this.autocapitalize)}
-              autocomplete=${ifDefined(this.type === 'password' ? 'off' : this.autocomplete)}
-              autocorrect=${ifDefined(this.type === 'password' ? 'off' : this.autocorrect)}
+              autocapitalize=${ifDefined(this.autocapitalize)}
+              autocomplete=${ifDefined(this.autocomplete)}
+              autocorrect=${ifDefined(this.autocorrect)}
               ?autofocus=${this.autofocus}
               spellcheck=${this.spellcheck}
               pattern=${ifDefined(this.pattern)}

src/components/menu-item/menu-item.styles.ts

@@ -60,16 +60,16 @@ export default css`
     margin-inline-start: var(--sl-spacing-x-small);
   }
 
-  :host(:focus) {
+  :host(:focus-visible) {
     outline: none;
   }
 
-  :host(:hover:not([aria-disabled='true'])) .menu-item {
+  :host(:hover:not([aria-disabled='true'], :focus-visible)) .menu-item {
     background-color: var(--sl-color-neutral-100);
     color: var(--sl-color-neutral-1000);
   }
 
-  :host(:focus) .menu-item {
+  :host(:focus-visible) .menu-item {
     outline: none;
     background-color: var(--sl-color-primary-600);
     color: var(--sl-color-neutral-0);
@@ -93,7 +93,7 @@ export default css`
 
   @media (forced-colors: active) {
     :host(:hover:not([aria-disabled='true'])) .menu-item,
-    :host(:focus) .menu-item {
+    :host(:focus-visible) .menu-item {
       outline: dashed 1px SelectedItem;
       outline-offset: -1px;
     }

src/components/menu/menu.test.ts

@@ -4,7 +4,7 @@ import { html } from 'lit';
 import { sendKeys } from '@web/test-runner-commands';
 import sinon from 'sinon';
 import type SlMenu from './menu';
-import type SlMenuItem from '../menu-item/menu-item';
+import type SlSelectEvent from '../../events/sl-select';
 
 describe('<sl-menu>', () => {
   it('emits sl-select with the correct event detail when clicking an item', async () => {
@@ -17,8 +17,8 @@ describe('<sl-menu>', () => {
       </sl-menu>
     `);
     const item2 = menu.querySelectorAll('sl-menu-item')[1];
-    const selectHandler = sinon.spy((event: CustomEvent) => {
-      const item = event.detail.item as SlMenuItem; // eslint-disable-line
+    const selectHandler = sinon.spy((event: SlSelectEvent) => {
+      const item = event.detail.item;
       if (item !== item2) {
         expect.fail('Incorrect event detail emitted with sl-select');
       }
@@ -40,8 +40,8 @@ describe('<sl-menu>', () => {
       </sl-menu>
     `);
     const [item1, item2] = menu.querySelectorAll('sl-menu-item');
-    const selectHandler = sinon.spy((event: CustomEvent) => {
-      const item = event.detail.item as SlMenuItem; // eslint-disable-line
+    const selectHandler = sinon.spy((event: SlSelectEvent) => {
+      const item = event.detail.item;
       if (item !== item2) {
         expect.fail('Incorrect item selected');
       }

src/components/option/option.test.ts

@@ -41,4 +41,14 @@ describe('<sl-option>', () => {
 
     expect(slotChangeHandler).to.have.been.calledOnce;
   });
+
+  it('should convert non-string values to string', async () => {
+    const el = await fixture<SlOption>(html` <sl-option>Text</sl-option> `);
+
+    // @ts-expect-error - intentional
+    el.value = 10;
+    await el.updateComplete;
+
+    expect(el.value).to.equal('10');
+  });
 });

src/components/option/option.ts

@@ -92,6 +92,12 @@ export default class SlOption extends ShoelaceElement {
 
   @watch('value')
   handleValueChange() {
+    // Ensure the value is a string. This ensures the next line doesn't error and allows framework users to pass numbers
+    // instead of requiring them to cast the value to a string.
+    if (typeof this.value !== 'string') {
+      this.value = String(this.value);
+    }
+
     if (this.value.includes(' ')) {
       console.error(`Option values cannot include a space. All spaces have been replaced with underscores.`, this);
       this.value = this.value.replace(/ /g, '_');

src/components/popup/popup.ts

@@ -1,7 +1,8 @@
-import { arrow, autoUpdate, computePosition, flip, offset, shift, size } from '@floating-ui/dom';
+import { arrow, autoUpdate, computePosition, flip, offset, platform, shift, size } from '@floating-ui/dom';
 import { classMap } from 'lit/directives/class-map.js';
 import { customElement, property, query } from 'lit/decorators.js';
 import { html } from 'lit';
+import { offsetParent } from 'composed-offset-position';
 import ShoelaceElement from '../../internal/shoelace-element';
 import styles from './popup.styles';
 import type { CSSResultGroup } from 'lit';
@@ -76,8 +77,8 @@ export default class SlPopup extends ShoelaceElement {
     | 'left-end' = 'top';
 
   /**
-   * Determines how the popup is positioned. The `absolute` strategy works well in most cases, but if
-   * overflow is clipped, using a `fixed` position strategy can often workaround it.
+   * Determines how the popup is positioned. The `absolute` strategy works well in most cases, but if overflow is
+   * clipped, using a `fixed` position strategy can often workaround it.
    */
   @property({ reflect: true }) strategy: 'absolute' | 'fixed' = 'absolute';
 
@@ -365,10 +366,24 @@ export default class SlPopup extends ShoelaceElement {
       );
     }
 
+    //
+    // Use custom positioning logic if the strategy is absolute. Otherwise, fall back to the default logic.
+    //
+    // More info: https://github.com/shoelace-style/shoelace/issues/1135
+    //
+    const getOffsetParent =
+      this.strategy === 'absolute'
+        ? (element: Element) => platform.getOffsetParent(element, offsetParent)
+        : platform.getOffsetParent;
+
     computePosition(this.anchorEl, this.popup, {
       placement: this.placement,
       middleware,
-      strategy: this.strategy
+      strategy: this.strategy,
+      platform: {
+        ...platform,
+        getOffsetParent
+      }
     }).then(({ x, y, middlewareData, placement }) => {
       //
       // Even though we have our own localization utility, it uses different heuristics to determine RTL. Because of

src/components/qr-code/qr-code.ts

@@ -72,7 +72,7 @@ export default class SlQrCode extends ShoelaceElement {
         part="base"
         class="qr-code"
         role="img"
-        aria-label=${this.label.length > 0 ? this.label : this.value}
+        aria-label=${this.label?.length > 0 ? this.label : this.value}
         style=${styleMap({
           width: `${this.size}px`,
           height: `${this.size}px`

src/components/radio-button/radio-button.ts

@@ -51,7 +51,10 @@ export default class SlRadioButton extends ShoelaceElement {
   /** Disables the radio button. */
   @property({ type: Boolean, reflect: true }) disabled = false;
 
-  /** The radio button's size. */
+  /**
+   * The radio button's size. When used inside a radio group, the size will be determined by the radio group's size so
+   * this attribute can typically be omitted.
+   */
   @property({ reflect: true }) size: 'small' | 'medium' | 'large' = 'medium';
 
   /** Draws a pill-style radio button with rounded edges. */

src/components/radio-group/radio-group.test.ts

@@ -3,6 +3,7 @@ import { clickOnElement } from '../../internal/test';
 import { runFormControlBaseTests } from '../../internal/test/form-control-base-tests';
 import { sendKeys } from '@web/test-runner-commands';
 import sinon from 'sinon';
+import type SlChangeEvent from '../../events/sl-change';
 import type SlRadio from '../radio/radio';
 import type SlRadioGroup from './radio-group';
 
@@ -150,30 +151,30 @@ describe('<sl-radio-group>', () => {
       expect(radioGroup.hasAttribute('data-user-invalid')).to.be.false;
       expect(radioGroup.hasAttribute('data-user-valid')).to.be.false;
     });
-  });
 
-  it('should show a constraint validation error when setCustomValidity() is called', async () => {
-    const form = await fixture<HTMLFormElement>(html`
-      <form>
-        <sl-radio-group value="1">
-          <sl-radio id="radio-1" name="a" value="1"></sl-radio>
-          <sl-radio id="radio-2" name="a" value="2"></sl-radio>
-        </sl-radio-group>
-        <sl-button type="submit">Submit</sl-button>
-      </form>
-    `);
-    const button = form.querySelector('sl-button')!;
-    const radioGroup = form.querySelector<SlRadioGroup>('sl-radio-group')!;
-    const submitHandler = sinon.spy((event: SubmitEvent) => event.preventDefault());
+    it('should show a constraint validation error when setCustomValidity() is called', async () => {
+      const form = await fixture<HTMLFormElement>(html`
+        <form>
+          <sl-radio-group value="1">
+            <sl-radio id="radio-1" name="a" value="1"></sl-radio>
+            <sl-radio id="radio-2" name="a" value="2"></sl-radio>
+          </sl-radio-group>
+          <sl-button type="submit">Submit</sl-button>
+        </form>
+      `);
+      const button = form.querySelector('sl-button')!;
+      const radioGroup = form.querySelector<SlRadioGroup>('sl-radio-group')!;
+      const submitHandler = sinon.spy((event: SubmitEvent) => event.preventDefault());
 
-    // Submitting the form after setting custom validity should not trigger the handler
-    radioGroup.setCustomValidity('Invalid selection');
-    form.addEventListener('submit', submitHandler);
-    button.click();
+      // Submitting the form after setting custom validity should not trigger the handler
+      radioGroup.setCustomValidity('Invalid selection');
+      form.addEventListener('submit', submitHandler);
+      button.click();
 
-    await aTimeout(100);
+      await aTimeout(100);
 
-    expect(submitHandler).to.not.have.been.called;
+      expect(submitHandler).to.not.have.been.called;
+    });
   });
 });
 
@@ -251,6 +252,34 @@ describe('when submitting a form', () => {
   });
 });
 
+describe('when a size is applied', () => {
+  it('should apply the same size to all radios', async () => {
+    const radioGroup = await fixture<SlRadioGroup>(html`
+      <sl-radio-group size="large">
+        <sl-radio id="radio-1" value="1"></sl-radio>
+        <sl-radio id="radio-2" value="2"></sl-radio>
+      </sl-radio-group>
+    `);
+    const [radio1, radio2] = radioGroup.querySelectorAll('sl-radio')!;
+
+    expect(radio1.size).to.equal('large');
+    expect(radio2.size).to.equal('large');
+  });
+
+  it('should apply the same size to all radio buttons', async () => {
+    const radioGroup = await fixture<SlRadioGroup>(html`
+      <sl-radio-group size="large">
+        <sl-radio-button id="radio-1" value="1"></sl-radio-button>
+        <sl-radio-button id="radio-2" value="2"></sl-radio-button>
+      </sl-radio-group>
+    `);
+    const [radio1, radio2] = radioGroup.querySelectorAll('sl-radio-button')!;
+
+    expect(radio1.size).to.equal('large');
+    expect(radio2.size).to.equal('large');
+  });
+});
+
 describe('when the value changes', () => {
   it('should emit sl-change when toggled with the arrow keys', async () => {
     const radioGroup = await fixture<SlRadioGroup>(html`
@@ -283,7 +312,7 @@ describe('when the value changes', () => {
     `);
     const radio = radioGroup.querySelector<SlRadio>('#radio-1')!;
     setTimeout(() => radio.click());
-    const event = (await oneEvent(radioGroup, 'sl-change')) as CustomEvent;
+    const event = (await oneEvent(radioGroup, 'sl-change')) as SlChangeEvent;
     expect(event.target).to.equal(radioGroup);
     expect(radioGroup.value).to.equal('1');
   });
@@ -298,7 +327,7 @@ describe('when the value changes', () => {
     const radio = radioGroup.querySelector<SlRadio>('#radio-1')!;
     radio.focus();
     setTimeout(() => sendKeys({ press: ' ' }));
-    const event = (await oneEvent(radioGroup, 'sl-change')) as CustomEvent;
+    const event = (await oneEvent(radioGroup, 'sl-change')) as SlChangeEvent;
     expect(event.target).to.equal(radioGroup);
     expect(radioGroup.value).to.equal('1');
   });

src/components/radio-group/radio-group.ts

@@ -71,6 +71,9 @@ export default class SlRadioGroup extends ShoelaceElement implements ShoelaceFor
   /** The current value of the radio group, submitted as a name/value pair with form data. */
   @property({ reflect: true }) value = '';
 
+  /** The radio group's size. This size will be applied to all child radios and radio buttons. */
+  @property({ reflect: true }) size: 'small' | 'medium' | 'large' = 'medium';
+
   /**
    * By default, form controls are associated with the nearest containing `<form>` element. This attribute allows you
    * to place the form control outside of a form and associate it with the form that has this `id`. The form must be in
@@ -197,27 +200,40 @@ export default class SlRadioGroup extends ShoelaceElement implements ShoelaceFor
   }
 
   private handleSlotChange() {
-    const radios = this.getAllRadios();
+    if (customElements.get('sl-radio') || customElements.get('sl-radio-button')) {
+      const radios = this.getAllRadios();
 
-    radios.forEach(radio => (radio.checked = radio.value === this.value));
+      // Sync the checked state and size
+      radios.forEach(radio => {
+        radio.checked = radio.value === this.value;
+        radio.size = this.size;
+      });
 
-    this.hasButtonGroup = radios.some(radio => radio.tagName.toLowerCase() === 'sl-radio-button');
+      this.hasButtonGroup = radios.some(radio => radio.tagName.toLowerCase() === 'sl-radio-button');
+
+      if (!radios.some(radio => radio.checked)) {
+        if (this.hasButtonGroup) {
+          const buttonRadio = radios[0].shadowRoot?.querySelector('button');
+
+          if (buttonRadio) {
+            buttonRadio.tabIndex = 0;
+          }
+        } else {
+          radios[0].tabIndex = 0;
+        }
+      }
 
-    if (!radios.some(radio => radio.checked)) {
       if (this.hasButtonGroup) {
-        const buttonRadio = radios[0].shadowRoot!.querySelector('button')!;
-        buttonRadio.tabIndex = 0;
-      } else {
-        radios[0].tabIndex = 0;
-      }
-    }
+        const buttonGroup = this.shadowRoot?.querySelector('sl-button-group');
 
-    if (this.hasButtonGroup) {
-      const buttonGroup = this.shadowRoot?.querySelector('sl-button-group');
-
-      if (buttonGroup) {
-        buttonGroup.disableRole = true;
+        if (buttonGroup) {
+          buttonGroup.disableRole = true;
+        }
       }
+    } else {
+      // Rerun this handler when <sl-radio> or <sl-radio-button> is registered
+      customElements.whenDefined('sl-radio').then(() => this.handleSlotChange());
+      customElements.whenDefined('sl-radio-button').then(() => this.handleSlotChange());
     }
   }
 
@@ -252,12 +268,9 @@ export default class SlRadioGroup extends ShoelaceElement implements ShoelaceFor
     return true;
   }
 
-  /** Sets a custom validation message. Pass an empty string to restore validity. */
-  setCustomValidity(message = '') {
-    this.customValidityMessage = message;
-    this.errorMessage = message;
-    this.validationInput.setCustomValidity(message);
-    this.formControlController.updateValidity();
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
   }
 
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
@@ -279,6 +292,14 @@ export default class SlRadioGroup extends ShoelaceElement implements ShoelaceFor
     return isValid;
   }
 
+  /** Sets a custom validation message. Pass an empty string to restore validity. */
+  setCustomValidity(message = '') {
+    this.customValidityMessage = message;
+    this.errorMessage = message;
+    this.validationInput.setCustomValidity(message);
+    this.formControlController.updateValidity();
+  }
+
   render() {
     const hasLabelSlot = this.hasSlotController.test('label');
     const hasHelpTextSlot = this.hasSlotController.test('help-text');
@@ -299,7 +320,9 @@ export default class SlRadioGroup extends ShoelaceElement implements ShoelaceFor
         part="form-control"
         class=${classMap({
           'form-control': true,
-          'form-control--medium': true,
+          'form-control--small': this.size === 'small',
+          'form-control--medium': this.size === 'medium',
+          'form-control--large': this.size === 'large',
           'form-control--radio-group': true,
           'form-control--has-label': hasLabel,
           'form-control--has-help-text': hasHelpText

src/components/radio/radio.ts

@@ -36,7 +36,10 @@ export default class SlRadio extends ShoelaceElement {
   /** The radio's value. When selected, the radio group will receive this value. */
   @property() value: string;
 
-  /** The radio's size. */
+  /**
+   * The radio's size. When used inside a radio group, the size will be determined by the radio group's size so this
+   * attribute can typically be omitted.
+   */
   @property({ reflect: true }) size: 'small' | 'medium' | 'large' = 'medium';
 
   /** Disables the radio. */

src/components/range/range.ts

@@ -1,5 +1,5 @@
 import { classMap } from 'lit/directives/class-map.js';
-import { customElement, property, query, state } from 'lit/decorators.js';
+import { customElement, eventOptions, property, query, state } from 'lit/decorators.js';
 import { defaultValue } from '../../internal/default-value';
 import { FormControlController } from '../../internal/form';
 import { HasSlotController } from '../../internal/slot';
@@ -156,6 +156,7 @@ export default class SlRange extends ShoelaceElement implements ShoelaceFormCont
     this.emit('sl-focus');
   }
 
+  @eventOptions({ passive: true })
   private handleThumbDragStart() {
     this.hasTooltip = true;
   }
@@ -254,6 +255,11 @@ export default class SlRange extends ShoelaceElement implements ShoelaceFormCont
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.input.reportValidity();

src/components/rating/rating.test.ts

@@ -79,6 +79,20 @@ describe('<sl-rating>', () => {
     expect(el.value).to.equal(1);
   });
 
+  it('should not emit sl-change when disabled', async () => {
+    const el = await fixture<SlRating>(html` <sl-rating value="5" disabled></sl-rating> `);
+    const lastSymbol = el.shadowRoot!.querySelector<HTMLSpanElement>('.rating__symbol:last-child')!;
+    const changeHandler = sinon.spy();
+
+    el.addEventListener('sl-change', changeHandler);
+
+    await clickOnElement(lastSymbol);
+    await el.updateComplete;
+
+    expect(changeHandler).to.not.have.been.called;
+    expect(el.value).to.equal(5);
+  });
+
   it('should not emit sl-change when the value is changed programmatically', async () => {
     const el = await fixture<SlRating>(html` <sl-rating label="Test" value="1"></sl-rating> `);
     el.addEventListener('sl-change', () => expect.fail('sl-change incorrectly emitted'));

src/components/rating/rating.ts

@@ -1,7 +1,7 @@
 import '../icon/icon';
 import { clamp } from '../../internal/math';
 import { classMap } from 'lit/directives/class-map.js';
-import { customElement, property, query, state } from 'lit/decorators.js';
+import { customElement, eventOptions, property, query, state } from 'lit/decorators.js';
 import { html } from 'lit';
 import { LocalizeController } from '../../utilities/localize';
 import { styleMap } from 'lit/directives/style-map.js';
@@ -89,6 +89,10 @@ export default class SlRating extends ShoelaceElement {
   }
 
   private handleClick(event: MouseEvent) {
+    if (this.disabled) {
+      return;
+    }
+
     this.setValue(this.getValueFromMousePosition(event));
     this.emit('sl-change');
   }
@@ -159,6 +163,7 @@ export default class SlRating extends ShoelaceElement {
     event.preventDefault();
   }
 
+  @eventOptions({ passive: true })
   private handleTouchMove(event: TouchEvent) {
     this.hoverValue = this.getValueFromTouchPosition(event);
   }

src/components/select/select.styles.ts

@@ -85,6 +85,8 @@ export default css`
 
   .select__value-input {
     position: absolute;
+    top: 0;
+    left: 0;
     width: 100%;
     height: 100%;
     padding: 0;

src/components/select/select.test.ts

@@ -8,15 +8,31 @@ import type SlOption from '../option/option';
 import type SlSelect from './select';
 
 describe('<sl-select>', () => {
-  it('should pass accessibility tests', async () => {
-    const el = await fixture<SlSelect>(html`
-      <sl-select label="Select one">
-        <sl-option value="option-1">Option 1</sl-option>
-        <sl-option value="option-2">Option 2</sl-option>
-        <sl-option value="option-3">Option 3</sl-option>
-      </sl-select>
-    `);
-    await expect(el).to.be.accessible();
+  describe('accessibility', () => {
+    it('should pass accessibility tests when closed', async () => {
+      const select = await fixture<SlSelect>(html`
+        <sl-select label="Select one">
+          <sl-option value="option-1">Option 1</sl-option>
+          <sl-option value="option-2">Option 2</sl-option>
+          <sl-option value="option-3">Option 3</sl-option>
+        </sl-select>
+      `);
+      await expect(select).to.be.accessible();
+    });
+
+    it('should pass accessibility tests when open', async () => {
+      const select = await fixture<SlSelect>(html`
+        <sl-select label="Select one">
+          <sl-option value="option-1">Option 1</sl-option>
+          <sl-option value="option-2">Option 2</sl-option>
+          <sl-option value="option-3">Option 3</sl-option>
+        </sl-select>
+      `);
+
+      await select.show();
+
+      await expect(select).to.be.accessible();
+    });
   });
 
   it('should be disabled with the disabled attribute', async () => {
@@ -162,6 +178,32 @@ describe('<sl-select>', () => {
 
       await el.updateComplete;
     });
+
+    it('should emit sl-change and sl-input with the correct validation message when the value changes', async () => {
+      const el = await fixture<SlSelect>(html`
+        <sl-select required>
+          <sl-option value="option-1">Option 1</sl-option>
+          <sl-option value="option-2">Option 2</sl-option>
+          <sl-option value="option-3">Option 3</sl-option>
+        </sl-select>
+      `);
+      const option2 = el.querySelectorAll('sl-option')[1];
+      const handler = sinon.spy((event: CustomEvent) => {
+        if (el.validationMessage) {
+          expect.fail(`Validation message should be empty when ${event.type} is emitted and a value is set`);
+        }
+      });
+
+      el.addEventListener('sl-change', handler);
+      el.addEventListener('sl-input', handler);
+
+      await clickOnElement(el);
+      await aTimeout(500);
+      await clickOnElement(option2);
+      await el.updateComplete;
+
+      expect(handler).to.be.calledTwice;
+    });
   });
 
   it('should open the listbox when any letter key is pressed with sl-select is on focus', async () => {

src/components/select/select.ts

@@ -19,6 +19,7 @@ import type { CSSResultGroup } from 'lit';
 import type { ShoelaceFormControl } from '../../internal/shoelace-element';
 import type SlOption from '../option/option';
 import type SlPopup from '../popup/popup';
+import type SlRemoveEvent from '../../events/sl-remove';
 
 /**
  * @summary Selects allow you to choose items from a menu of predefined options.
@@ -58,6 +59,10 @@ import type SlPopup from '../popup/popup';
  * @csspart listbox - The listbox container where options are slotted.
  * @csspart tags - The container that houses option tags when `multiselect` is used.
  * @csspart tag - The individual tags that represent each multiselect option.
+ * @csspart tag__base - The tag's base part.
+ * @csspart tag__content - The tag's content part.
+ * @csspart tag__remove-button - The tag's remove button.
+ * @csspart tag__remove-button__base - The tag's remove button base part.
  * @csspart clear-button - The clear button.
  * @csspart expand-icon - The container that wraps the expand icon.
  */
@@ -252,8 +257,11 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
           this.setSelectedOptions(this.currentOption);
         }
 
-        this.emit('sl-input');
-        this.emit('sl-change');
+        // Emit after updating
+        this.updateComplete.then(() => {
+          this.emit('sl-input');
+          this.emit('sl-change');
+        });
 
         if (!this.multiple) {
           this.hide();
@@ -377,9 +385,13 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
     if (this.value !== '') {
       this.setSelectedOptions([]);
       this.displayInput.focus({ preventScroll: true });
-      this.emit('sl-clear');
-      this.emit('sl-input');
-      this.emit('sl-change');
+
+      // Emit after update
+      this.updateComplete.then(() => {
+        this.emit('sl-clear');
+        this.emit('sl-input');
+        this.emit('sl-change');
+      });
     }
   }
 
@@ -405,8 +417,11 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
       this.updateComplete.then(() => this.displayInput.focus({ preventScroll: true }));
 
       if (this.value !== oldValue) {
-        this.emit('sl-input');
-        this.emit('sl-change');
+        // Emit after updating
+        this.updateComplete.then(() => {
+          this.emit('sl-input');
+          this.emit('sl-change');
+        });
       }
 
       if (!this.multiple) {
@@ -422,27 +437,28 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
     const values: string[] = [];
 
     // Check for duplicate values in menu items
-    allOptions.forEach(option => {
-      if (values.includes(option.value)) {
-        console.error(
-          `An option with a duplicate value of "${option.value}" has been found in <sl-select>. All options must have unique values.`,
-          option
-        );
-      }
-      values.push(option.value);
-    });
+    if (customElements.get('sl-option')) {
+      allOptions.forEach(option => values.push(option.value));
 
-    // Select only the options that match the new value
-    this.setSelectedOptions(allOptions.filter(el => value.includes(el.value)));
+      // Select only the options that match the new value
+      this.setSelectedOptions(allOptions.filter(el => value.includes(el.value)));
+    } else {
+      // Rerun this handler when <sl-option> is registered
+      customElements.whenDefined('sl-option').then(() => this.handleDefaultSlotChange());
+    }
   }
 
-  private handleTagRemove(event: CustomEvent, option: SlOption) {
+  private handleTagRemove(event: SlRemoveEvent, option: SlOption) {
     event.stopPropagation();
 
     if (!this.disabled) {
       this.toggleOptionSelection(option, false);
-      this.emit('sl-input');
-      this.emit('sl-change');
+
+      // Emit after updating
+      this.updateComplete.then(() => {
+        this.emit('sl-input');
+        this.emit('sl-change');
+      });
     }
   }
 
@@ -624,6 +640,11 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
     return this.valueInput.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.valueInput.reportValidity();
@@ -741,10 +762,16 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
                           return html`
                             <sl-tag
                               part="tag"
+                              exportparts="
+                                base:tag__base,
+                                content:tag__content,
+                                remove-button:tag__remove-button,
+                                remove-button__base:tag__remove-button__base
+                              "
                               ?pill=${this.pill}
                               size=${this.size}
                               removable
-                              @sl-remove=${(event: CustomEvent) => this.handleTagRemove(event, option)}
+                              @sl-remove=${(event: SlRemoveEvent) => this.handleTagRemove(event, option)}
                             >
                               ${option.getTextLabel()}
                             </sl-tag>
@@ -794,7 +821,7 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
               </slot>
             </div>
 
-            <slot
+            <div
               id="listbox"
               role="listbox"
               aria-expanded=${this.open ? 'true' : 'false'}
@@ -805,7 +832,9 @@ export default class SlSelect extends ShoelaceElement implements ShoelaceFormCon
               tabindex="-1"
               @mouseup=${this.handleOptionClick}
               @slotchange=${this.handleDefaultSlotChange}
-            ></slot>
+            >
+              <slot></slot>
+            </div>
           </sl-popup>
         </div>
 

src/components/spinner/spinner.styles.ts

@@ -34,7 +34,6 @@ export default css`
   .spinner__track {
     stroke: var(--track-color);
     transform-origin: 0% 0%;
-    mix-blend-mode: multiply;
   }
 
   .spinner__indicator {

src/components/split-panel/split-panel.test.ts

@@ -2,8 +2,17 @@ import { expect, fixture, html } from '@open-wc/testing';
 
 describe('<sl-split-panel>', () => {
   it('should render a component', async () => {
-    const el = await fixture(html` <sl-split-panel></sl-split-panel> `);
+    const splitPanel = await fixture(html` <sl-split-panel></sl-split-panel> `);
 
-    expect(el).to.exist;
+    expect(splitPanel).to.exist;
+  });
+
+  it('should be accessible', async () => {
+    const splitPanel = await fixture(html`<sl-split-panel>
+      <div slot="start">Start</div>
+      <div slot="end">End</div>
+    </sl-split-panel>`);
+
+    await expect(splitPanel).to.be.accessible();
   });
 });

src/components/split-panel/split-panel.ts

@@ -249,17 +249,21 @@ export default class SlSplitPanel extends ShoelaceElement {
     return html`
       <slot name="start" part="panel start" class="start"></slot>
 
-      <slot
-        name="divider"
+      <div
         part="divider"
         class="divider"
         tabindex=${ifDefined(this.disabled ? undefined : '0')}
         role="separator"
+        aria-valuenow=${this.position}
+        aria-valuemin="0"
+        aria-valuemax="100"
         aria-label=${this.localize.term('resize')}
         @keydown=${this.handleKeyDown}
         @mousedown=${this.handleDrag}
         @touchstart=${this.handleDrag}
-      ></slot>
+      >
+        <slot name="divider"></slot>
+      </div>
 
       <slot name="end" part="panel end" class="end"></slot>
     `;

src/components/switch/switch.ts

@@ -163,6 +163,11 @@ export default class SlSwitch extends ShoelaceElement implements ShoelaceFormCon
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.input.reportValidity();

src/components/tab-group/tab-group.test.ts

@@ -9,16 +9,13 @@ import type { HTMLTemplateResult } from 'lit';
 import type SlTab from '../tab/tab';
 import type SlTabGroup from './tab-group';
 import type SlTabPanel from '../tab-panel/tab-panel';
+import type SlTabShowEvent from '../../events/sl-tab-show';
 
 interface ClientRectangles {
   body?: DOMRect;
   navigation?: DOMRect;
 }
 
-interface CustomEventPayload {
-  name: string;
-}
-
 const waitForScrollButtonsToBeRendered = async (tabGroup: SlTabGroup): Promise<void> => {
   await waitUntil(() => {
     const scrollButtons = tabGroup.shadowRoot?.querySelectorAll('sl-icon-button');
@@ -57,9 +54,9 @@ const expectOnlyOneTabPanelToBeActive = async (container: HTMLElement, dataTestI
   expect(activeTabPanels[0]).to.have.attribute('data-testid', dataTestIdOfActiveTab);
 };
 
-const expectPromiseToHaveName = async (showEventPromise: Promise<CustomEvent>, expectedName: string) => {
+const expectPromiseToHaveName = async (showEventPromise: Promise<SlTabShowEvent>, expectedName: string) => {
   const showEvent = await showEventPromise;
-  expect((showEvent.detail as CustomEventPayload).name).to.equal(expectedName);
+  expect(showEvent.detail.name).to.equal(expectedName);
 };
 
 const waitForHeaderToBeActive = async (container: HTMLElement, headerTestId: string): Promise<SlTab> => {
@@ -306,7 +303,7 @@ describe('<sl-tab-group>', () => {
       const customHeader = queryByTestId<SlTab>(tabGroup, 'custom-header');
       expect(customHeader).not.to.have.attribute('active');
 
-      const showEventPromise = oneEvent(tabGroup, 'sl-tab-show') as Promise<CustomEvent>;
+      const showEventPromise = oneEvent(tabGroup, 'sl-tab-show') as Promise<SlTabShowEvent>;
       await action();
 
       expect(customHeader).to.have.attribute('active');
@@ -405,7 +402,7 @@ describe('<sl-tab-group>', () => {
       const customHeader = queryByTestId<SlTab>(tabGroup, 'custom-header');
       expect(customHeader).not.to.have.attribute('active');
 
-      const showEventPromise = oneEvent(tabGroup, 'sl-tab-show') as Promise<CustomEvent>;
+      const showEventPromise = oneEvent(tabGroup, 'sl-tab-show') as Promise<SlTabShowEvent>;
       await sendKeys({ press: 'ArrowRight' });
       await aTimeout(0);
       expect(generalHeader).to.have.attribute('active');

src/components/tab-group/tab-group.ts

@@ -70,6 +70,11 @@ export default class SlTabGroup extends ShoelaceElement {
   @property({ attribute: 'no-scroll-controls', type: Boolean }) noScrollControls = false;
 
   connectedCallback() {
+    const whenAllDefined = Promise.allSettled([
+      customElements.whenDefined('sl-tab'),
+      customElements.whenDefined('sl-tab-panel')
+    ]);
+
     super.connectedCallback();
 
     this.resizeObserver = new ResizeObserver(() => {
@@ -89,20 +94,24 @@ export default class SlTabGroup extends ShoelaceElement {
       }
     });
 
+    // After the first update...
     this.updateComplete.then(() => {
       this.syncTabsAndPanels();
       this.mutationObserver.observe(this, { attributes: true, childList: true, subtree: true });
       this.resizeObserver.observe(this.nav);
 
-      // Set initial tab state when the tabs first become visible
-      const intersectionObserver = new IntersectionObserver((entries, observer) => {
-        if (entries[0].intersectionRatio > 0) {
-          this.setAriaLabels();
-          this.setActiveTab(this.getActiveTab() ?? this.tabs[0], { emitEvents: false });
-          observer.unobserve(entries[0].target);
-        }
+      // Wait for tabs and tab panels to be registered
+      whenAllDefined.then(() => {
+        // Set initial tab state when the tabs become visible
+        const intersectionObserver = new IntersectionObserver((entries, observer) => {
+          if (entries[0].intersectionRatio > 0) {
+            this.setAriaLabels();
+            this.setActiveTab(this.getActiveTab() ?? this.tabs[0], { emitEvents: false });
+            observer.unobserve(entries[0].target);
+          }
+        });
+        intersectionObserver.observe(this.tabGroup);
       });
-      intersectionObserver.observe(this.tabGroup);
     });
   }
 
@@ -316,6 +325,9 @@ export default class SlTabGroup extends ShoelaceElement {
     this.tabs = this.getAllTabs({ includeDisabled: false });
     this.panels = this.getAllPanels();
     this.syncIndicator();
+
+    // After updating, show or hide scroll controls as needed
+    this.updateComplete.then(() => this.updateScrollControls());
   }
 
   @watch('noScrollControls', { waitUntilFirstUpdate: true })

src/components/tab/tab.test.ts

@@ -1,6 +1,8 @@
 import { expect, fixture, html } from '@open-wc/testing';
 import sinon from 'sinon';
+import type SlIconButton from '../icon-button/icon-button';
 import type SlTab from './tab';
+import type SlTabGroup from '../tab-group/tab-group';
 
 describe('<sl-tab>', () => {
   it('passes accessibility test', async () => {
@@ -88,17 +90,31 @@ describe('<sl-tab>', () => {
   });
 
   describe('closable', () => {
-    it('should emit close event when close button clicked', async () => {
-      const el = await fixture<SlTab>(html` <sl-tab closable>Test</sl-tab> `);
+    it('should emit close event when the close button is clicked', async () => {
+      const tabGroup = await fixture<SlTabGroup>(html`
+        <sl-tab-group>
+          <sl-tab slot="nav" panel="general" closable>General</sl-tab>
+          <sl-tab slot="nav" panel="custom" closable>Custom</sl-tab>
+          <sl-tab-panel name="general">This is the general tab panel.</sl-tab-panel>
+          <sl-tab-panel name="custom">This is the custom tab panel.</sl-tab-panel>
+        </sl-tab-group>
+      `);
+      const closeButton = tabGroup
+        .querySelectorAll('sl-tab')[0]!
+        .shadowRoot!.querySelector<SlIconButton>('[part~="close-button"]')!;
 
-      const closeButton = el.shadowRoot!.querySelector<HTMLButtonElement>('[part~="close-button"]')!;
-      const spy = sinon.spy();
+      const handleClose = sinon.spy();
+      const handleTabShow = sinon.spy();
 
-      el.addEventListener('sl-close', spy, { once: true });
+      tabGroup.addEventListener('sl-close', handleClose, { once: true });
+      // The sl-tab-show event shouldn't be emitted when clicking the close button
+      tabGroup.addEventListener('sl-tab-show', handleTabShow);
 
       closeButton.click();
+      await closeButton?.updateComplete;
 
-      expect(spy.called).to.equal(true);
+      expect(handleClose.called).to.equal(true);
+      expect(handleTabShow.called).to.equal(false);
     });
   });
 });

src/components/tab/tab.ts

@@ -53,7 +53,8 @@ export default class SlTab extends ShoelaceElement {
     this.setAttribute('role', 'tab');
   }
 
-  private handleCloseClick() {
+  private handleCloseClick(event: Event) {
+    event.stopPropagation();
     this.emit('sl-close');
   }
 

src/components/textarea/textarea.ts

@@ -281,6 +281,11 @@ export default class SlTextarea extends ShoelaceElement implements ShoelaceFormC
     return this.input.checkValidity();
   }
 
+  /** Gets the associated form, if one exists. */
+  getForm(): HTMLFormElement | null {
+    return this.formControlController.getForm();
+  }
+
   /** Checks for validity and shows the browser's validation message if the control is invalid. */
   reportValidity() {
     return this.input.reportValidity();

src/components/tree-item/tree-item.styles.ts

@@ -26,7 +26,6 @@ export default css`
     color: var(--sl-color-neutral-700);
     cursor: pointer;
     user-select: none;
-    white-space: nowrap;
   }
 
   .tree-item__checkbox {
@@ -39,7 +38,7 @@ export default css`
     font-family: var(--sl-font-sans);
     font-size: var(--sl-font-size-medium);
     font-weight: var(--sl-font-weight-normal);
-    line-height: var(--sl-line-height-normal);
+    line-height: var(--sl-line-height-dense);
     letter-spacing: var(--sl-letter-spacing-normal);
   }
 
@@ -63,6 +62,7 @@ export default css`
     padding: var(--sl-spacing-x-small);
     width: 1rem;
     height: 1rem;
+    flex-shrink: 0;
     cursor: pointer;
   }
 

src/components/tree-item/tree-item.ts

@@ -263,12 +263,11 @@ export default class SlTreeItem extends ShoelaceElement {
                   ?disabled="${this.disabled}"
                   ?checked="${live(this.selected)}"
                   ?indeterminate="${this.indeterminate}"
-                >
-                  <slot class="tree-item__label" part="label"></slot>
-                </sl-checkbox>
-              `,
-            () => html` <slot class="tree-item__label" part="label"></slot> `
+                ></sl-checkbox>
+              `
           )}
+
+          <slot class="tree-item__label" part="label"></slot>
         </div>
 
         <slot

src/components/tree/tree.test.ts

@@ -1,4 +1,5 @@
-import { expect, fixture, html, triggerBlurFor, triggerFocusFor } from '@open-wc/testing';
+import { aTimeout, expect, fixture, html, triggerBlurFor, triggerFocusFor } from '@open-wc/testing';
+import { clickOnElement } from '../../internal/test';
 import { sendKeys } from '@web/test-runner-commands';
 import sinon from 'sinon';
 import type SlTree from './tree';
@@ -433,7 +434,7 @@ describe('<sl-tree>', () => {
         const expandButton: HTMLElement = node.shadowRoot!.querySelector('.tree-item__expand-button')!;
 
         // Act
-        expandButton.click();
+        await clickOnElement(expandButton);
         await el.updateComplete;
 
         // Assert
@@ -453,10 +454,10 @@ describe('<sl-tree>', () => {
           await el.updateComplete;
 
           // Act
-          node0.click();
+          await clickOnElement(node0);
           await el.updateComplete;
 
-          node1.click();
+          await clickOnElement(node1);
           await el.updateComplete;
 
           // Assert
@@ -474,10 +475,10 @@ describe('<sl-tree>', () => {
           await el.updateComplete;
 
           // Act
-          node0.click();
+          await clickOnElement(node0);
           await el.updateComplete;
 
-          node1.click();
+          await clickOnElement(node1);
           await el.updateComplete;
 
           // Assert
@@ -492,7 +493,7 @@ describe('<sl-tree>', () => {
           await el.updateComplete;
 
           // Act
-          parentNode.click();
+          await clickOnElement(parentNode);
           await parentNode.updateComplete;
 
           // Assert
@@ -511,10 +512,10 @@ describe('<sl-tree>', () => {
           await el.updateComplete;
 
           // Act
-          node0.click();
+          await clickOnElement(node0);
           await el.updateComplete;
 
-          node1.click();
+          await clickOnElement(node1);
           await el.updateComplete;
 
           // Assert
@@ -529,7 +530,7 @@ describe('<sl-tree>', () => {
           const parentNode = el.children[2] as SlTreeItem;
 
           // Act
-          parentNode.click();
+          await clickOnElement(parentNode);
           await el.updateComplete;
 
           // Assert
@@ -549,7 +550,10 @@ describe('<sl-tree>', () => {
           const childNode = parentNode.children[0] as SlTreeItem;
 
           // Act
-          childNode.click();
+          parentNode.expanded = true;
+          await parentNode.updateComplete;
+          await aTimeout(300);
+          await clickOnElement(childNode);
           await el.updateComplete;
 
           // Assert
@@ -572,9 +576,9 @@ describe('<sl-tree>', () => {
           const node = el.children[0] as SlTreeItem;
 
           // Act
-          node.click();
+          await clickOnElement(node);
           await el.updateComplete;
-          node.click();
+          await clickOnElement(node);
           await Promise.all([node.updateComplete, el.updateComplete]);
 
           // Assert
@@ -598,9 +602,9 @@ describe('<sl-tree>', () => {
         const node = el.children[0] as SlTreeItem;
 
         // Act
-        node.click();
+        await clickOnElement(node);
         await el.updateComplete;
-        node.click();
+        await clickOnElement(node);
         await Promise.all([node.updateComplete, el.updateComplete]);
 
         // Assert
@@ -621,7 +625,7 @@ describe('<sl-tree>', () => {
         const node = el.querySelector<SlTreeItem>('#expandable')!;
 
         // Act
-        node.click();
+        await clickOnElement(node);
         await Promise.all([node.updateComplete, el.updateComplete]);
 
         // Assert
@@ -643,9 +647,9 @@ describe('<sl-tree>', () => {
         const node = el.children[0] as SlTreeItem;
 
         // Act
-        node.click();
+        await clickOnElement(node);
         await Promise.all([node.updateComplete, el.updateComplete]);
-        node.click();
+        await clickOnElement(node);
         await Promise.all([node.updateComplete, el.updateComplete]);
 
         // Assert

src/components/tree/tree.ts

@@ -54,7 +54,7 @@ function syncCheckboxes(changedTreeItem: SlTreeItem, initialSync = false) {
  * @status stable
  * @since 2.0
  *
- * @event {{ selection: TreeItem[] }} sl-selection-change - Emitted when a tree item is selected or deselected.
+ * @event {{ selection: SlTreeItem[] }} sl-selection-change - Emitted when a tree item is selected or deselected.
  *
  * @slot - The default slot.
  * @slot expand-icon - The icon to show when the tree item is expanded. Works best with `<sl-icon>`.
@@ -90,6 +90,7 @@ export default class SlTree extends ShoelaceElement {
   private lastFocusedItem: SlTreeItem;
   private readonly localize = new LocalizeController(this);
   private mutationObserver: MutationObserver;
+  private clickTarget: SlTreeItem | null = null;
 
   async connectedCallback() {
     super.connectedCallback();
@@ -292,13 +293,20 @@ export default class SlTree extends ShoelaceElement {
   }
 
   private handleClick(event: Event) {
-    const target = event.target as HTMLElement;
+    const target = event.target as SlTreeItem;
     const treeItem = target.closest('sl-tree-item')!;
     const isExpandButton = event
       .composedPath()
       .some((el: HTMLElement) => el?.classList?.contains('tree-item__expand-button'));
 
-    if (!treeItem || treeItem.disabled) {
+    //
+    // Don't Do anything if there's no tree item, if it's disabled, or if the click doesn't match the initial target
+    // from mousedown. The latter case prevents the user from starting a click on one item and ending it on another,
+    // causing the parent node to collapse.
+    //
+    // See https://github.com/shoelace-style/shoelace/issues/1082
+    //
+    if (!treeItem || treeItem.disabled || target !== this.clickTarget) {
       return;
     }
 
@@ -309,6 +317,11 @@ export default class SlTree extends ShoelaceElement {
     }
   }
 
+  handleMouseDown(event: MouseEvent) {
+    // Record the click target so we know which item the click initially targeted
+    this.clickTarget = event.target as SlTreeItem;
+  }
+
   private handleFocusOut(event: FocusEvent) {
     const relatedTarget = event.relatedTarget as HTMLElement;
 
@@ -392,7 +405,13 @@ export default class SlTree extends ShoelaceElement {
 
   render() {
     return html`
-      <div part="base" class="tree" @click=${this.handleClick} @keydown=${this.handleKeyDown}>
+      <div
+        part="base"
+        class="tree"
+        @click=${this.handleClick}
+        @keydown=${this.handleKeyDown}
+        @mousedown=${this.handleMouseDown}
+      >
         <slot @slotchange=${this.handleSlotChange}></slot>
         <slot name="expand-icon" hidden aria-hidden="true"> </slot>
         <slot name="collapse-icon" hidden aria-hidden="true"> </slot>

src/events/events.ts

@@ -0,0 +1,34 @@
+export { default as SlAfterCollapseEvent } from './sl-after-collapse';
+export { default as SlAfterExpandEvent } from './sl-after-expand';
+export { default as SlAfterHideEvent } from './sl-after-hide';
+export { default as SlAfterShowEvent } from './sl-after-show';
+export { default as SlBlurEvent } from './sl-blur';
+export { default as SlCancelEvent } from './sl-cancel';
+export { default as SlChangeEvent } from './sl-change';
+export { default as SlClearEvent } from './sl-clear';
+export { default as SlCloseEvent } from './sl-close';
+export { default as SlCollapseEvent } from './sl-collapse';
+export { default as SlErrorEvent } from './sl-error';
+export { default as SlExpandEvent } from './sl-expand';
+export { default as SlFinishEvent } from './sl-finish';
+export { default as SlFocusEvent } from './sl-focus';
+export { default as SlHideEvent } from './sl-hide';
+export { default as SlHoverEvent } from './sl-hover';
+export { default as SlInitialFocusEvent } from './sl-initial-focus';
+export { default as SlInputEvent } from './sl-input';
+export { default as SlInvalidEvent } from './sl-invalid';
+export { default as SlLazyChangeEvent } from './sl-lazy-change';
+export { default as SlLazyLoadEvent } from './sl-lazy-load';
+export { default as SlLoadEvent } from './sl-load';
+export { default as SlMutationEvent } from './sl-mutation';
+export { default as SlRemoveEvent } from './sl-remove';
+export { default as SlRepositionEvent } from './sl-reposition';
+export { default as SlRequestCloseEvent } from './sl-request-close';
+export { default as SlResizeEvent } from './sl-resize';
+export { default as SlSelectEvent } from './sl-select';
+export { default as SlSelectionChangeEvent } from './sl-selection-change';
+export { default as SlShowEvent } from './sl-show';
+export { default as SlSlideChange } from './sl-slide-change';
+export { default as SlStartEvent } from './sl-start';
+export { default as SlTabHideEvent } from './sl-tab-hide';
+export { default as SlTabShowEvent } from './sl-tab-show';

src/events/sl-after-collapse.ts

@@ -0,0 +1,9 @@
+type SlAfterCollapseEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-after-collapse': SlAfterCollapseEvent;
+  }
+}
+
+export default SlAfterCollapseEvent;

src/events/sl-after-expand.ts

@@ -0,0 +1,9 @@
+type SlAfterExpandEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-after-expand': SlAfterExpandEvent;
+  }
+}
+
+export default SlAfterExpandEvent;

src/events/sl-after-hide.ts

@@ -0,0 +1,9 @@
+type SlAfterHideEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-after-hide': SlAfterHideEvent;
+  }
+}
+
+export default SlAfterHideEvent;

src/events/sl-after-show.ts

@@ -0,0 +1,9 @@
+type SlAfterShowEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-after-show': SlAfterShowEvent;
+  }
+}
+
+export default SlAfterShowEvent;

src/events/sl-blur.ts

@@ -0,0 +1,9 @@
+type SlBlurEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-blur': SlBlurEvent;
+  }
+}
+
+export default SlBlurEvent;

src/events/sl-cancel.ts

@@ -0,0 +1,9 @@
+type SlCancelEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-cancel': SlCancelEvent;
+  }
+}
+
+export default SlCancelEvent;

src/events/sl-change.ts

@@ -0,0 +1,9 @@
+type SlChangeEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-change': SlChangeEvent;
+  }
+}
+
+export default SlChangeEvent;

src/events/sl-clear.ts

@@ -0,0 +1,9 @@
+type SlClearEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-clear': SlClearEvent;
+  }
+}
+
+export default SlClearEvent;

src/events/sl-close.ts

@@ -0,0 +1,9 @@
+type SlCloseEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-close': SlCloseEvent;
+  }
+}
+
+export default SlCloseEvent;

src/events/sl-collapse.ts

@@ -0,0 +1,9 @@
+type SlCollapseEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-collapse': SlCollapseEvent;
+  }
+}
+
+export default SlCollapseEvent;

src/events/sl-error.ts

@@ -0,0 +1,9 @@
+type SlErrorEvent = CustomEvent<{ status?: number }>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-error': SlErrorEvent;
+  }
+}
+
+export default SlErrorEvent;

src/events/sl-expand.ts

@@ -0,0 +1,9 @@
+type SlExpandEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-expand': SlExpandEvent;
+  }
+}
+
+export default SlExpandEvent;

src/events/sl-finish.ts

@@ -0,0 +1,9 @@
+type SlFinishEvent = CustomEvent<Record<PropertyKey, never>>;
+
+declare global {
+  interface GlobalEventHandlersEventMap {
+    'sl-finish': SlFinishEvent;
+  }
+}
+
+export default SlFinishEvent;