From 39d29204cab1d371f2981306aca097892a9cf925 Mon Sep 17 00:00:00 2001
From: b84330808 <b84330808@gmail.com>
Date: Wed, 28 Oct 2026 14:03:14 +0900
Subject: [PATCH 1/4] fix(types): add declarative shadow DOM attributes to
 <template>

`<template shadowrootmode="open">` failed to type check because
TemplateHTMLAttributes had no shadowroot* attributes. Add shadowrootmode
('open' | 'closed') and the shadowrootclonable, shadowrootdelegatesfocus
and shadowrootserializable booleans, each with its camelCase property
form like the other attributes in dom.d.ts.

Fixes #5337

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 src/dom.d.ts                      |  8 ++++++++
 test/ts/dom-attributes.test-d.tsx | 22 ++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/src/dom.d.ts b/src/dom.d.ts
index fe4b399dd5..61e39b9706 100644
--- a/src/dom.d.ts
+++ b/src/dom.d.ts
@@ -2786,6 +2786,14 @@ export interface TemplateHTMLAttributes<
 	T extends EventTarget = HTMLTemplateElement
 > extends HTMLAttributes<T> {
 	role?: never;
+	shadowrootclonable?: Signalish<boolean | undefined>;
+	shadowRootClonable?: Signalish<boolean | undefined>;
+	shadowrootdelegatesfocus?: Signalish<boolean | undefined>;
+	shadowRootDelegatesFocus?: Signalish<boolean | undefined>;
+	shadowrootmode?: Signalish<'open' | 'closed' | undefined>;
+	shadowRootMode?: Signalish<'open' | 'closed' | undefined>;
+	shadowrootserializable?: Signalish<boolean | undefined>;
+	shadowRootSerializable?: Signalish<boolean | undefined>;
 }
 
 export interface TextareaHTMLAttributes<
diff --git a/test/ts/dom-attributes.test-d.tsx b/test/ts/dom-attributes.test-d.tsx
index 333cc7edcf..aa2c33ba09 100644
--- a/test/ts/dom-attributes.test-d.tsx
+++ b/test/ts/dom-attributes.test-d.tsx
@@ -344,3 +344,25 @@ const dangerouslySetInnerHTML = (
 		<div dangerouslySetInnerHTML={{ __html: 'string' }} />
 	</>
 );
+
+const declarativeShadowRoot = (
+	<>
+		<template shadowrootmode="open" />
+		<template shadowrootmode="closed" />
+		<template shadowRootMode={createSignal('open' as const)} />
+		<template
+			shadowrootmode="open"
+			shadowrootclonable
+			shadowrootdelegatesfocus
+			shadowrootserializable
+		/>
+		<template
+			shadowRootMode="closed"
+			shadowRootClonable={false}
+			shadowRootDelegatesFocus={true}
+			shadowRootSerializable
+		/>
+	</>
+);
+// @ts-expect-error shadowrootmode only accepts "open" or "closed"
+const invalidShadowRootMode = <template shadowrootmode="none" />;

From 31511830355ebc5b6918fd8426965b52c8e12264 Mon Sep 17 00:00:00 2001
From: b84330808 <b84330808@gmail.com>
Date: Wed, 28 Oct 2026 16:52:42 +0900
Subject: [PATCH 2/4] Drop the type tests, per review

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 test/ts/dom-attributes.test-d.tsx | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/test/ts/dom-attributes.test-d.tsx b/test/ts/dom-attributes.test-d.tsx
index aa2c33ba09..333cc7edcf 100644
--- a/test/ts/dom-attributes.test-d.tsx
+++ b/test/ts/dom-attributes.test-d.tsx
@@ -344,25 +344,3 @@ const dangerouslySetInnerHTML = (
 		<div dangerouslySetInnerHTML={{ __html: 'string' }} />
 	</>
 );
-
-const declarativeShadowRoot = (
-	<>
-		<template shadowrootmode="open" />
-		<template shadowrootmode="closed" />
-		<template shadowRootMode={createSignal('open' as const)} />
-		<template
-			shadowrootmode="open"
-			shadowrootclonable
-			shadowrootdelegatesfocus
-			shadowrootserializable
-		/>
-		<template
-			shadowRootMode="closed"
-			shadowRootClonable={false}
-			shadowRootDelegatesFocus={true}
-			shadowRootSerializable
-		/>
-	</>
-);
-// @ts-expect-error shadowrootmode only accepts "open" or "closed"
-const invalidShadowRootMode = <template shadowrootmode="none" />;

From 4ab827e2d2ba3d35b2d69d48862835a47a84211b Mon Sep 17 00:00:00 2001
From: b84330808 <b84330808@gmail.com>
Date: Wed, 28 Oct 2026 16:52:44 +0900
Subject: [PATCH 3/4] test: drop the template shadow root type tests

Per review: these type additions do not need their own tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 test/ts/dom-attributes.test-d.tsx | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/test/ts/dom-attributes.test-d.tsx b/test/ts/dom-attributes.test-d.tsx
index 333cc7edcf..aa2c33ba09 100644
--- a/test/ts/dom-attributes.test-d.tsx
+++ b/test/ts/dom-attributes.test-d.tsx
@@ -344,3 +344,25 @@ const dangerouslySetInnerHTML = (
 		<div dangerouslySetInnerHTML={{ __html: 'string' }} />
 	</>
 );
+
+const declarativeShadowRoot = (
+	<>
+		<template shadowrootmode="open" />
+		<template shadowrootmode="closed" />
+		<template shadowRootMode={createSignal('open' as const)} />
+		<template
+			shadowrootmode="open"
+			shadowrootclonable
+			shadowrootdelegatesfocus
+			shadowrootserializable
+		/>
+		<template
+			shadowRootMode="closed"
+			shadowRootClonable={false}
+			shadowRootDelegatesFocus={true}
+			shadowRootSerializable
+		/>
+	</>
+);
+// @ts-expect-error shadowrootmode only accepts "open" or "closed"
+const invalidShadowRootMode = <template shadowrootmode="none" />;

From 9069f5a164395aca4ab9f710993b93521ebe811f Mon Sep 17 00:00:00 2001
From: b84330808 <b84330808@gmail.com>
Date: Wed, 28 Oct 2026 16:53:19 +0900
Subject: [PATCH 4/4] test: remove the type tests again

My previous commit re-added them by mistake.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 test/ts/dom-attributes.test-d.tsx | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/test/ts/dom-attributes.test-d.tsx b/test/ts/dom-attributes.test-d.tsx
index aa2c33ba09..333cc7edcf 100644
--- a/test/ts/dom-attributes.test-d.tsx
+++ b/test/ts/dom-attributes.test-d.tsx
@@ -344,25 +344,3 @@ const dangerouslySetInnerHTML = (
 		<div dangerouslySetInnerHTML={{ __html: 'string' }} />
 	</>
 );
-
-const declarativeShadowRoot = (
-	<>
-		<template shadowrootmode="open" />
-		<template shadowrootmode="closed" />
-		<template shadowRootMode={createSignal('open' as const)} />
-		<template
-			shadowrootmode="open"
-			shadowrootclonable
-			shadowrootdelegatesfocus
-			shadowrootserializable
-		/>
-		<template
-			shadowRootMode="closed"
-			shadowRootClonable={false}
-			shadowRootDelegatesFocus={true}
-			shadowRootSerializable
-		/>
-	</>
-);
-// @ts-expect-error shadowrootmode only accepts "open" or "closed"
-const invalidShadowRootMode = <template shadowrootmode="none" />;