chore: throw more helpful error when encoding uri fails during preren…

…dering (#9053)

closes #9045

.changeset/seven-teachers-tell.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+chore: throw more helpful error when encoding uri fails during prerendering

packages/kit/src/core/postbuild/prerender.js

@@ -4,7 +4,7 @@ import { pathToFileURL } from 'node:url';
 import { installPolyfills } from '../../exports/node/polyfills.js';
 import { mkdirp, posixify, walk } from '../../utils/filesystem.js';
 import { should_polyfill } from '../../utils/platform.js';
-import { is_root_relative, resolve } from '../../utils/url.js';
+import { decode_uri, is_root_relative, resolve } from '../../utils/url.js';
 import { escape_html_attr } from '../../utils/escape.js';
 import { logger } from '../utils.js';
 import { load_config } from '../config/index.js';
@@ -207,15 +207,15 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 			// this seems circuitous, but using new URL allows us to not care
 			// whether dependency_path is encoded or not
 			const encoded_dependency_path = new URL(dependency_path, 'http://localhost').pathname;
-			const decoded_dependency_path = decodeURI(encoded_dependency_path);
+			const decoded_dependency_path = decode_uri(encoded_dependency_path);
 
 			const headers = Object.fromEntries(result.response.headers);
 
 			const prerender = headers['x-sveltekit-prerender'];
 			if (prerender) {
 				const encoded_route_id = headers['x-sveltekit-routeid'];
 				if (encoded_route_id != null) {
-					const route_id = decodeURI(encoded_route_id);
+					const route_id = decode_uri(encoded_route_id);
 					const existing_value = prerender_map.get(route_id);
 					if (existing_value !== 'auto') {
 						prerender_map.set(route_id, prerender === 'true' ? true : 'auto');
@@ -257,7 +257,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 				}
 
 				if (hash) {
-					const key = decodeURI(pathname + hash);
+					const key = decode_uri(pathname + hash);
 
 					if (!expected_hashlinks.has(key)) {
 						expected_hashlinks.set(key, new Set());
@@ -266,7 +266,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 					/** @type {Set<string>} */ (expected_hashlinks.get(key)).add(decoded);
 				}
 
-				enqueue(decoded, decodeURI(pathname), pathname);
+				enqueue(decoded, decode_uri(pathname), pathname);
 			}
 		}
 	}
@@ -293,7 +293,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 		if (written.has(file)) return;
 
 		const encoded_route_id = response.headers.get('x-sveltekit-routeid');
-		const route_id = encoded_route_id != null ? decodeURI(encoded_route_id) : null;
+		const route_id = encoded_route_id != null ? decode_uri(encoded_route_id) : null;
 		if (route_id !== null) prerendered_routes.add(route_id);
 
 		if (response_type === REDIRECT) {
@@ -302,7 +302,7 @@ async function prerender({ out, manifest_path, metadata, verbose, env }) {
 			if (location) {
 				const resolved = resolve(encoded, location);
 				if (is_root_relative(resolved)) {
-					enqueue(decoded, decodeURI(resolved), resolved);
+					enqueue(decoded, decode_uri(resolved), resolved);
 				}
 
 				if (!headers['x-sveltekit-normalize']) {

packages/kit/src/utils/url.js

@@ -75,6 +75,21 @@ export function decode_params(params) {
 	return params;
 }
 
+/**
+ * The error when a URL is malformed is not very helpful, so we augment it with the URI
+ * @param {string} uri
+ */
+export function decode_uri(uri) {
+	try {
+		return decodeURI(uri);
+	} catch (e) {
+		if (e instanceof Error) {
+			e.message = `Failed to decode URI: ${uri}\n` + e.message;
+		}
+		throw e;
+	}
+}
+
 /**
  * URL properties that could change during the lifetime of the page,
  * which excludes things like `origin`