get rid of spread_dynamic_element_attributes_effect

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

@@ -343,6 +343,8 @@ function serialize_dynamic_element_attributes(attributes, context, element_id) {
 		return false;
 	}
 
+	// TODO why are we always treating this as a spread? needs docs, if that's not an error
+
 	let needs_isolation = false;
 	let is_reactive = false;
 
@@ -365,23 +367,11 @@ function serialize_dynamic_element_attributes(attributes, context, element_id) {
 			attribute.type === 'SpreadAttribute' && attribute.metadata.contains_call_expression;
 	}
 
-	const isolated = b.stmt(
+	if (needs_isolation || is_reactive) {
-		b.call(
-			'$.spread_dynamic_element_attributes_effect',
-			element_id,
-			b.thunk(b.array(values)),
-			b.literal(context.state.analysis.css.hash)
-		)
-	);
-
-	if (needs_isolation) {
-		context.state.init.push(isolated);
-		return false;
-	} else if (is_reactive) {
 		const id = context.state.scope.generate('spread_attributes');
 		context.state.init.push(b.let(id));
-		context.state.update.push(
+
-			b.stmt(
+		const update = b.stmt(
 			b.assignment(
 				'=',
 				b.id(id),
@@ -393,10 +383,17 @@ function serialize_dynamic_element_attributes(attributes, context, element_id) {
 					b.literal(context.state.analysis.css.hash)
 				)
 			)
-			)
 		);
+
+		if (needs_isolation) {
+			context.state.init.push(serialize_update(update));
+			return false;
+		}
+
+		context.state.update.push(update);
 		return true;
-	} else {
+	}
+
 	context.state.init.push(
 		b.stmt(
 			b.call(
@@ -409,7 +406,6 @@ function serialize_dynamic_element_attributes(attributes, context, element_id) {
 		)
 	);
 	return false;
-	}
 }
 
 /**

packages/svelte/src/internal/client/dom/elements/attributes.js

@@ -184,20 +184,6 @@ export function spread_attributes(element, prev, attrs, lowercase_attributes, cs
 	return next;
 }
 
-/**
- * @param {Element} node
- * @param {() => Record<string, unknown>[]} attrs
- * @param {string} css_hash
- */
-export function spread_dynamic_element_attributes_effect(node, attrs, css_hash) {
-	/** @type {Record<string, any> | undefined} */
-	var current;
-
-	render_effect(() => {
-		current = spread_dynamic_element_attributes(node, current, attrs(), css_hash);
-	});
-}
-
 /**
  * @param {Element} node
  * @param {Record<string, unknown> | undefined} prev