From c0c653b18bae99ae9125c63f2a78d498d3469be2 Mon Sep 17 00:00:00 2001
From: Ben McCann <322311+benmccann@users.noreply.github.com>
Date: Sat, 6 Jan 2024 14:50:12 -0800
Subject: [PATCH] custom elements

---
 .../phases/3-transform/client/visitors/template.js  | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js b/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
index 0a8080b4ec..832871932e 100644
--- a/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
+++ b/packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js
@@ -644,7 +644,10 @@ function serialize_custom_element_attribute_update_assignment(node_id, attribute
 		};
 	};
 
-	if (attribute.metadata.dynamic) {
+	const { has_expression_tag, can_inline } = Array.isArray(attribute.value)
+		? can_inline_all_nodes(attribute.value, context.state)
+		: { has_expression_tag: false, can_inline: true };
+	if (attribute.metadata.dynamic && !can_inline) {
 		const id = state.scope.generate(`${node_id.name}_${name}`);
 		// TODO should this use the if condition? what if someone mutates the value passed to the ce?
 		serialize_update_assignment(
@@ -657,7 +660,13 @@ function serialize_custom_element_attribute_update_assignment(node_id, attribute
 		);
 		return true;
 	} else {
-		state.init.push(assign(grouped_value).grouped);
+		if (has_expression_tag && can_inline) {
+			push_template_quasi(context.state, ` ${name}="`);
+			push_template_expression(context.state, grouped_value);
+			push_template_quasi(context.state, `"`);
+		} else {
+			state.init.push(assign(grouped_value).grouped);
+		}
 		return false;
 	}
 }