From cf6b64c6c0220068abb2843fea78b125b8767f44 Mon Sep 17 00:00:00 2001
From: Dominic Gannaway <trueadm@users.noreply.github.com>
Date: Fri, 30 Aug 2024 22:38:43 +0100
Subject: [PATCH] fix: error on incorrect attributes for svelte:body (#13084)

* fix: error on spreading attributes for svelte:body

* tweak
---
 .changeset/eleven-icons-sniff.md                       |  5 +++++
 packages/svelte/messages/compile-errors/template.md    |  4 ++++
 packages/svelte/src/compiler/errors.js                 |  9 +++++++++
 .../compiler/phases/2-analyze/visitors/SvelteBody.js   | 10 ++++++++++
 .../client/visitors/shared/special_element.js          |  1 -
 5 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/eleven-icons-sniff.md

diff --git a/.changeset/eleven-icons-sniff.md b/.changeset/eleven-icons-sniff.md
new file mode 100644
index 000000000000..fd2b1af9c53f
--- /dev/null
+++ b/.changeset/eleven-icons-sniff.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: error on incorrect attributes for svelte:body
diff --git a/packages/svelte/messages/compile-errors/template.md b/packages/svelte/messages/compile-errors/template.md
index f27ed90fb469..a71716b06dae 100644
--- a/packages/svelte/messages/compile-errors/template.md
+++ b/packages/svelte/messages/compile-errors/template.md
@@ -274,6 +274,10 @@ HTML restricts where certain elements can appear. In case of a violation the bro
 
 > A component can have a single top-level `<style>` element
 
+## svelte_body_illegal_attribute
+
+> `<svelte:body>` does not support non-event attributes or spread attributes
+
 ## svelte_component_invalid_this
 
 > Invalid component definition — must be an `{expression}`
diff --git a/packages/svelte/src/compiler/errors.js b/packages/svelte/src/compiler/errors.js
index dd70be6435a7..ae89f4902e88 100644
--- a/packages/svelte/src/compiler/errors.js
+++ b/packages/svelte/src/compiler/errors.js
@@ -1183,6 +1183,15 @@ export function style_duplicate(node) {
 	e(node, "style_duplicate", "A component can have a single top-level `<style>` element");
 }
 
+/**
+ * `<svelte:body>` does not support non-event attributes or spread attributes
+ * @param {null | number | NodeLike} node
+ * @returns {never}
+ */
+export function svelte_body_illegal_attribute(node) {
+	e(node, "svelte_body_illegal_attribute", "`<svelte:body>` does not support non-event attributes or spread attributes");
+}
+
 /**
  * Invalid component definition — must be an `{expression}`
  * @param {null | number | NodeLike} node
diff --git a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
index 72a2f0806e54..7d71de41b0a0 100644
--- a/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
+++ b/packages/svelte/src/compiler/phases/2-analyze/visitors/SvelteBody.js
@@ -1,5 +1,7 @@
 /** @import { SvelteBody } from '#compiler' */
 /** @import { Context } from '../types' */
+import * as e from '../../../errors.js';
+import { is_event_attribute } from '../../../utils/ast.js';
 import { disallow_children } from './shared/special-element.js';
 
 /**
@@ -8,5 +10,13 @@ import { disallow_children } from './shared/special-element.js';
  */
 export function SvelteBody(node, context) {
 	disallow_children(node);
+	for (const attribute of node.attributes) {
+		if (
+			attribute.type === 'SpreadAttribute' ||
+			(attribute.type === 'Attribute' && !is_event_attribute(attribute))
+		) {
+			e.svelte_body_illegal_attribute(attribute);
+		}
+	}
 	context.next();
 }
diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/special_element.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/special_element.js
index 6a0be55949b7..7bacf7103452 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/special_element.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/shared/special_element.js
@@ -1,7 +1,6 @@
 /** @import { Expression } from 'estree' */
 /** @import { SvelteBody, SvelteDocument, SvelteWindow } from '#compiler' */
 /** @import { ComponentContext } from '../../types' */
-import { is_event_attribute } from '../../../../../utils/ast.js';
 import * as b from '../../../../../utils/builders.js';
 
 /**