we don't actually need the function, we can flatten it. more efficient

Author: Rich-Harris

packages/svelte/src/compiler/phases/3-transform/client/visitors/template.js

@@ -896,7 +896,7 @@ function serialize_inline_component(node, component_name, context) {
 					'$.spread_props',
 					...props_and_spreads.map((p) => (Array.isArray(p) ? b.object(p) : p))
 				);
-	/** @param {import('estree').Identifier} node_id */
+	/** @param {import('estree').Expression} node_id */
 	let fn = (node_id) =>
 		b.call(
 			context.state.options.dev
@@ -937,34 +937,24 @@ function serialize_inline_component(node, component_name, context) {
 		};
 	}
 
+	const statements = [...snippet_declarations, ...binding_initializers];
+
 	if (Object.keys(custom_css_props).length > 0) {
 		context.state.template.push(
 			context.state.metadata.namespace === 'svg'
 				? '<g><!></g>'
 				: '<div style="display: contents"><!></div>'
 		);
 
-		return b.stmt(
-			b.call(
-				'$.css_props',
-				context.state.node,
-				b.thunk(b.object(custom_css_props)),
-				b.arrow(
-					[b.id('$$node')],
-					b.block([...snippet_declarations, ...binding_initializers, b.stmt(fn(b.id('$$node')))])
-				)
-			)
+		statements.push(
+			b.stmt(b.call('$.css_props', context.state.node, b.thunk(b.object(custom_css_props)))),
+			b.stmt(fn(b.member(context.state.node, b.id('lastChild'))))
 		);
+	} else {
+		context.state.template.push('<!>');
+		statements.push(b.stmt(fn(context.state.node)));
 	}
 
-	context.state.template.push('<!>');
-
-	const statements = [
-		...snippet_declarations,
-		...binding_initializers,
-		b.stmt(fn(context.state.node))
-	];
-
 	return statements.length > 1 ? b.block(statements) : statements[0];
 }
 

packages/svelte/src/compiler/phases/3-transform/server/transform-server.js

@@ -907,7 +907,6 @@ function serialize_element_spread_attributes(
  * @param {import('#compiler').Component | import('#compiler').SvelteComponent | import('#compiler').SvelteSelf} node
  * @param {string | import('estree').Expression} component_name
  * @param {import('./types').ComponentContext} context
- * @returns {import('estree').Statement}
  */
 function serialize_inline_component(node, component_name, context) {
 	/** @type {Array<import('estree').Property[] | import('estree').Expression>} */

packages/svelte/src/internal/client/dom/blocks/css-props.js

@@ -4,18 +4,15 @@ import { render_effect } from '../../reactivity/effects.js';
 /**
  * @param {HTMLDivElement | SVGGElement} element
  * @param {() => Record<string, string>} get_styles
- * @param {(anchor: Element | Text | Comment) => any} component
  * @returns {void}
  */
-export function css_props(element, get_styles, component) {
+export function css_props(element, get_styles) {
 	if (hydrating) {
 		set_hydrate_nodes(
 			/** @type {import('#client').TemplateNode[]} */ ([...element.childNodes]).slice(0, -1)
 		);
 	}
 
-	component(/** @type {Comment} */ (element.lastChild));
-
 	render_effect(() => {
 		render_effect(() => {
 			var styles = get_styles();