fix: ensure user effects are correctly executed on initialisation (#13697)

.changeset/brave-rivers-jam.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: ensure user effects are correctly executed on initialisation

packages/svelte/src/internal/client/reactivity/effects.js

@@ -192,8 +192,7 @@ export function user_effect(fn) {
 	// until the component is mounted
 	var defer =
 		active_effect !== null &&
-		(active_effect.f & RENDER_EFFECT) !== 0 &&
-		// TODO do we actually need this? removing them changes nothing
+		(active_effect.f & BRANCH_EFFECT) !== 0 &&
 		component_context !== null &&
 		!component_context.m;
 

packages/svelte/tests/runtime-runes/samples/effect-order-5/_config.js

@@ -0,0 +1,7 @@
+import { test } from '../../test';
+
+export default test({
+	async test({ assert, logs }) {
+		assert.deepEqual(logs, ['effect 1', 'effect 2']);
+	}
+});

packages/svelte/tests/runtime-runes/samples/effect-order-5/main.svelte

@@ -0,0 +1,15 @@
+<script>
+	$effect.pre(() => {
+		$effect(() => {
+			console.log('effect 1')
+		})
+	})
+
+	function template() {
+		$effect(() => {
+			console.log('effect 2')
+		});
+	}
+</script>
+
+{template()}