fix: remount at any hydration error

Author: 7nik

.changeset/hip-eagles-yawn.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: remount at any hydration error

packages/svelte/src/internal/client/render.js

@@ -136,20 +136,21 @@ export function hydrate(component, options) {
 
 		return /**  @type {Exports} */ (instance);
 	} catch (error) {
-		if (error === HYDRATION_ERROR) {
-			if (options.recover === false) {
-				e.hydration_failed();
-			}
-
-			// If an error occured above, the operations might not yet have been initialised.
-			init_operations();
-			clear_text_content(target);
+		if (error !== HYDRATION_ERROR) {
+			// eslint-disable-next-line no-console
+			console.error('Failed to hydrate: ', error);
+		}
 
-			set_hydrating(false);
-			return mount(component, options);
+		if (options.recover === false) {
+			e.hydration_failed();
 		}
 
-		throw error;
+		// If an error occured above, the operations might not yet have been initialised.
+		init_operations();
+		clear_text_content(target);
+
+		set_hydrating(false);
+		return mount(component, options);
 	} finally {
 		set_hydrating(was_hydrating);
 		set_hydrate_node(previous_hydrate_node);

packages/svelte/tests/hydration/samples/whitespace-at-block-start/Nested.svelte

@@ -0,0 +1 @@
+<p>nested</p>

packages/svelte/tests/hydration/samples/whitespace-at-block-start/_config.js

@@ -0,0 +1,21 @@
+import { test } from '../../test';
+
+/** @type {string[]} */
+let logs = [];
+/** @type {typeof console['error']} */
+let console_error;
+
+export default test({
+	before_test() {
+		console_error = console.error;
+		console.error = (...args) => logs.push(args.join(''));
+	},
+	after_test() {
+		console.error = console_error;
+	},
+	test({ deepEqual }) {
+		deepEqual(logs, [
+			"Failed to hydrate: HierarchyRequestError: Node can't be inserted in a #text parent."
+		]);
+	}
+});

packages/svelte/tests/hydration/samples/whitespace-at-block-start/_expected.html

@@ -0,0 +1 @@
+<main><p>nested</p><!----></main>

packages/svelte/tests/hydration/samples/whitespace-at-block-start/_override.html

@@ -0,0 +1,2 @@
+<!--[-->
+<main><p>nested</p><!----></main><!--]-->

packages/svelte/tests/hydration/samples/whitespace-at-block-start/main.svelte

@@ -0,0 +1,7 @@
+<script>
+	import Nested from './Nested.svelte';
+</script>
+
+<main>
+	<Nested />
+</main>

packages/svelte/tests/runtime-legacy/samples/keyed-each-dev-unique/_config.js

@@ -1,6 +1,7 @@
 import { test } from '../../test';
 
 export default test({
+	mode: ['server', 'client'],
 	compileOptions: {
 		dev: true
 	},

packages/svelte/tests/runtime-runes/samples/inspect-state-unsafe-mutation/_config.js

@@ -2,6 +2,7 @@ import { flushSync } from 'svelte';
 import { test } from '../../test';
 
 export default test({
+	mode: ['client'],
 	compileOptions: {
 		dev: true
 	},

packages/svelte/tests/runtime-runes/samples/props-bound-fallback/_config.js

@@ -5,6 +5,7 @@ import { test } from '../../test';
 // uses a prop it does not write to but has a fallback value
 export default test({
 	accessors: false, // so that prop actually becomes $.prop and not $.prop_source
+	mode: ['server', 'client'],
 	html: `<button>0</button><span>0</span>`,
 
 	test({ assert, target }) {