feat: add <svelte:html> element

closes #8663

Author: dummdidumm

.changeset/lemon-paws-work.md

@@ -0,0 +1,5 @@
+---
+'svelte': minor
+---
+
+feat: add `<svelte:html>` element

documentation/docs/05-special-elements/04-svelte-html.md

@@ -0,0 +1,11 @@
+---
+title: <svelte:html>
+---
+
+```svelte
+<svelte:html attribute={value} onevent={handler} />
+```
+
+Similarly to `<svelte:body>`, this element allows you to add properties and listeners to events on `document.documentElement`. This is useful for attributes such as `lang` which influence how the browser interprets the content.
+
+As with `<svelte:window>`, `<svelte:document>` and `<svelte:body>`, this element may only appear the top level of your component and must never be inside a block or element.

documentation/docs/05-special-elements/04-svelte-head.md renamed to documentation/docs/05-special-elements/05-svelte-head.md

@@ -798,6 +798,12 @@ Invalid component definition — must be an `{expression}`
 `<svelte:head>` cannot have attributes nor directives
 ```
 
+### svelte_html_illegal_attribute
+
+```
+`<svelte:html>` can only have regular attributes
+```
+
 ### svelte_meta_duplicate
 
 ```

documentation/docs/05-special-elements/05-svelte-element.md renamed to documentation/docs/05-special-elements/06-svelte-element.md

@@ -1998,6 +1998,7 @@ export interface SvelteHTMLElements {
 	'svelte:window': SvelteWindowAttributes;
 	'svelte:document': SvelteDocumentAttributes;
 	'svelte:body': HTMLAttributes<HTMLElement>;
+	'svelte:html': HTMLAttributes<HTMLElement>;
 	'svelte:fragment': { slot?: string };
 	'svelte:options': {
 		customElement?:

documentation/docs/05-special-elements/06-svelte-options.md renamed to documentation/docs/05-special-elements/07-svelte-options.md

@@ -306,6 +306,10 @@ HTML restricts where certain elements can appear. In case of a violation the bro
 
 > `<svelte:head>` cannot have attributes nor directives
 
+## svelte_html_illegal_attribute
+
+> `<svelte:html>` can only have regular attributes
+
 ## svelte_meta_duplicate
 
 > A component can only have one `<%name%>` element

documentation/docs/98-reference/.generated/compile-errors.md

@@ -1282,6 +1282,15 @@ export function svelte_head_illegal_attribute(node) {
 	e(node, "svelte_head_illegal_attribute", "`<svelte:head>` cannot have attributes nor directives");
 }
 
+/**
+ * `<svelte:html>` can only have regular attributes
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function svelte_html_illegal_attribute(node) {
+	e(node, "svelte_html_illegal_attribute", "`<svelte:html>` can only have regular attributes");
+}
+
 /**
  * A component can only have one `<%name%>` element
  * @param {null | number | NodeLike} node

packages/svelte/elements.d.ts

@@ -33,6 +33,7 @@ const root_only_meta_tags = new Map([
 	['svelte:head', 'SvelteHead'],
 	['svelte:options', 'SvelteOptions'],
 	['svelte:window', 'SvelteWindow'],
+	['svelte:html', 'SvelteHTML'],
 	['svelte:document', 'SvelteDocument'],
 	['svelte:body', 'SvelteBody']
 ]);