[fix] successfully handle client errors

.changeset/fast-cameras-bow.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[fix] successfully handle client errors

packages/kit/src/runtime/client/renderer.js

@@ -1,6 +1,7 @@
 import { writable } from 'svelte/store';
 import { hash } from '../hash.js';
 import { normalize } from '../load.js';
+import { coalesce_to_error } from '../utils.js';
 
 /** @param {any} value */
 function page_store(value) {
@@ -139,6 +140,8 @@ export class Renderer {
 		/** @type {import('./types').NavigationResult | undefined} */
 		let result;
 
+		let error_args;
+
 		try {
 			for (let i = 0; i < nodes.length; i += 1) {
 				const is_leaf = i === nodes.length - 1;
@@ -156,12 +159,12 @@ export class Renderer {
 				if (node && node.loaded) {
 					if (node.loaded.error) {
 						if (error) throw node.loaded.error;
-						result = await this._load_error({
+						error_args = {
 							status: node.loaded.status,
 							error: node.loaded.error,
 							path: page.path,
 							query: page.query
-						});
+						};
 					} else if (node.loaded.context) {
 						context = {
 							...context,
@@ -171,13 +174,15 @@ export class Renderer {
 				}
 			}
 
-			result = await this._get_navigation_result_from_branch({ page, branch });
-		} catch (e) {
+			result = error_args
+				? await this._load_error(error_args)
+				: await this._get_navigation_result_from_branch({ page, branch });
+		} catch (/** @type {unknown} */ e) {
 			if (error) throw e;
 
 			result = await this._load_error({
 				status: 500,
-				error: e,
+				error: coalesce_to_error(e),
 				path: page.path,
 				query: page.query
 			});

packages/kit/src/runtime/server/index.js

@@ -3,7 +3,8 @@ import { render_page } from './page/index.js';
 import { render_response } from './page/render.js';
 import { respond_with_error } from './page/respond_with_error.js';
 import { parse_body } from './parse_body/index.js';
-import { coalesce_to_error, lowercase_keys } from './utils.js';
+import { lowercase_keys } from './utils.js';
+import { coalesce_to_error } from '../utils.js';
 import { hash } from '../hash.js';
 
 /**

packages/kit/src/runtime/server/page/respond.js

@@ -1,7 +1,7 @@
 import { render_response } from './render.js';
 import { load_node } from './load_node.js';
 import { respond_with_error } from './respond_with_error.js';
-import { coalesce_to_error } from '../utils.js';
+import { coalesce_to_error } from '../../utils.js';
 
 /**
  * @typedef {import('./types.js').Loaded} Loaded

packages/kit/src/runtime/server/page/respond_with_error.js

@@ -1,6 +1,6 @@
 import { render_response } from './render.js';
 import { load_node } from './load_node.js';
-import { coalesce_to_error } from '../utils.js';
+import { coalesce_to_error } from '../../utils.js';
 
 /**
  * @param {{

packages/kit/src/runtime/server/utils.js

@@ -9,11 +9,3 @@ export function lowercase_keys(obj) {
 
 	return clone;
 }
-
-/**
- * @param {unknown} err
- * @return {Error}
- */
-export function coalesce_to_error(err) {
-	return err instanceof Error ? err : new Error(JSON.stringify(err));
-}

packages/kit/src/runtime/utils.js

@@ -0,0 +1,7 @@
+/**
+ * @param {unknown} err
+ * @return {Error}
+ */
+export function coalesce_to_error(err) {
+	return err instanceof Error ? err : new Error(JSON.stringify(err));
+}