[chore] improved typing for runtime and tests (#1995)

.changeset/itchy-days-wonder.md

@@ -0,0 +1,5 @@
+---
+'@sveltejs/kit': patch
+---
+
+[chore] improved typing for runtime and tests

packages/kit/src/core/adapter-utils.js

@@ -3,7 +3,7 @@
  *
  * This is intended to be used with both requests and responses, to have a consistent body parsing across adapters.
  *
- * @param {string?} content_type The `content-type` header of a request/response.
+ * @param {string|undefined|null} content_type The `content-type` header of a request/response.
  * @returns {boolean}
  */
 export function isContentTypeTextual(content_type) {

packages/kit/src/core/dev/index.js

@@ -18,7 +18,7 @@ import { get_server } from '../server/index.js';
 import { __fetch_polyfill } from '../../install-fetch.js';
 import { SVELTE_KIT } from '../constants.js';
 
-/** @typedef {{ cwd?: string, port: number, host: string, https: boolean, config: import('types/config').ValidatedConfig }} Options */
+/** @typedef {{ cwd?: string, port: number, host?: string, https: boolean, config: import('types/config').ValidatedConfig }} Options */
 /** @typedef {import('types/internal').SSRComponent} SSRComponent */
 
 /** @param {Options} opts */
@@ -47,9 +47,8 @@ class Watcher extends EventEmitter {
 		this.config = config;
 
 		/**
-		 * @type {vite.ViteDevServer}
+		 * @type {vite.ViteDevServer | undefined}
 		 */
-		// @ts-ignore
 		this.vite;
 
 		process.on('exit', () => {
@@ -198,6 +197,7 @@ class Watcher extends EventEmitter {
 					pattern: route.pattern,
 					params: get_params(route.params),
 					load: async () => {
+						if (!this.vite) throw new Error('Vite server has not been initialized');
 						const url = path.resolve(this.cwd, route.file);
 						return await this.vite.ssrLoadModule(url);
 					}
@@ -281,7 +281,7 @@ async function create_handler(vite, config, dir, cwd, manifest) {
 
 				if (req.url === '/favicon.ico') return;
 
-				/** @type {import('types/internal').Hooks} */
+				/** @type {Partial<import('types/internal').Hooks>} */
 				const hooks = resolve_entry(config.kit.files.hooks)
 					? await vite.ssrLoadModule(`/${config.kit.files.hooks}`)
 					: {};

packages/kit/src/core/start/index.js

@@ -17,7 +17,7 @@ const mutable = (dir) =>
 /**
  * @param {{
  *   port: number;
- *   host: string;
+ *   host?: string;
  *   config: import('types/config').ValidatedConfig;
  *   https?: boolean;
  *   cwd?: string;

packages/kit/src/runtime/app/navigation.js

@@ -19,6 +19,7 @@ export const prefetchRoutes = import.meta.env.SSR ? guard('prefetchRoutes') : pr
  * @type {import('$app/navigation').goto}
  */
 async function goto_(href, opts) {
+	// @ts-ignore
 	return router.goto(href, opts, []);
 }
 
@@ -27,13 +28,15 @@ async function goto_(href, opts) {
  */
 async function invalidate_(resource) {
 	const { href } = new URL(resource, location.href);
+	// @ts-ignore
 	return router.renderer.invalidate(href);
 }
 
 /**
  * @type {import('$app/navigation').prefetch}
  */
 function prefetch_(href) {
+	// @ts-ignore
 	return router.prefetch(new URL(href, get_base_uri(document)));
 }
 
@@ -42,10 +45,15 @@ function prefetch_(href) {
  */
 async function prefetchRoutes_(pathnames) {
 	const matching = pathnames
-		? router.routes.filter((route) => pathnames.some((pathname) => route[0].test(pathname)))
-		: router.routes;
-
-	const promises = matching.map((r) => r.length !== 1 && Promise.all(r[1].map((load) => load())));
+		? // @ts-ignore
+		  router.routes.filter((route) => pathnames.some((pathname) => route[0].test(pathname)))
+		: // @ts-ignore
+		  router.routes;
+
+	const promises = matching
+		.filter((r) => r && r.length > 1)
+		// @ts-ignore
+		.map((r) => Promise.all(r[1].map((load) => load())));
 
 	await Promise.all(promises);
 }

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

@@ -46,7 +46,7 @@ function initial_fetch(resource, opts) {
 	}
 
 	const script = document.querySelector(selector);
-	if (script) {
+	if (script && script.textContent) {
 		const { body, ...init } = JSON.parse(script.textContent);
 		return Promise.resolve(new Response(body, init));
 	}
@@ -69,8 +69,8 @@ export class Renderer {
 		this.fallback = fallback;
 		this.host = host;
 
-		/** @type {import('./router').Router} */
-		this.router = null;
+		/** @type {import('./router').Router | undefined} */
+		this.router;
 
 		this.target = target;
 
@@ -133,13 +133,13 @@ export class Renderer {
 		/** @type {Record<string, any>} */
 		let context = {};
 
-		/** @type {import('./types').NavigationResult} */
+		/** @type {import('./types').NavigationResult | undefined} */
 		let result;
 
-		/** @type {number} */
+		/** @type {number | undefined} */
 		let new_status;
 
-		/** @type {Error} new_error */
+		/** @type {Error | undefined} new_error */
 		let new_error;
 
 		try {
@@ -150,8 +150,8 @@ export class Renderer {
 					module: await nodes[i],
 					page,
 					context,
-					status: is_leaf && status,
-					error: is_leaf && error
+					status: is_leaf ? status : undefined,
+					error: is_leaf ? error : undefined
 				});
 
 				branch.push(node);
@@ -535,8 +535,9 @@ export class Renderer {
 	async _load({ route, path, query }, no_cache) {
 		const key = `${path}?${query}`;
 
-		if (!no_cache && this.cache.has(key)) {
-			return this.cache.get(key);
+		if (!no_cache) {
+			const cached = this.cache.get(key);
+			if (cached) return cached;
 		}
 
 		const [pattern, a, b, get_params] = route;

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

@@ -8,8 +8,8 @@ function scroll_state() {
 }
 
 /**
- * @param {Node} node
- * @returns {HTMLAnchorElement | SVGAElement}
+ * @param {Node | null} node
+ * @returns {HTMLAnchorElement | SVGAElement | null}
  */
 function find_anchor(node) {
 	while (node && node.nodeName.toUpperCase() !== 'A') node = node.parentNode; // SVG <a> elements have a lowercase name
@@ -121,7 +121,7 @@ export class Router {
 			// Ignore if tag has
 			// 1. 'download' attribute
 			// 2. 'rel' attribute includes external
-			const rel = a.getAttribute('rel') && a.getAttribute('rel').split(/\s+/);
+			const rel = (a.getAttribute('rel') || '').split(/\s+/);
 
 			if (a.hasAttribute('download') || (rel && rel.includes('external'))) {
 				return;
@@ -162,7 +162,7 @@ export class Router {
 
 	/**
 	 * @param {URL} url
-	 * @returns {import('./types').NavigationInfo}
+	 * @returns {import('./types').NavigationInfo | undefined}
 	 */
 	parse(url) {
 		if (this.owns(url)) {
@@ -221,12 +221,13 @@ export class Router {
 			throw new Error('Attempted to prefetch a URL that does not belong to this app');
 		}
 
+		// @ts-ignore
 		return this.renderer.load(info);
 	}
 
 	/**
 	 * @param {URL} url
-	 * @param {{ x: number, y: number }} scroll
+	 * @param {{ x: number, y: number }?} scroll
 	 * @param {boolean} keepfocus
 	 * @param {string[]} chain
 	 * @param {string} [hash]
@@ -246,19 +247,21 @@ export class Router {
 				(has_trailing_slash && this.trailing_slash === 'never') ||
 				(!has_trailing_slash &&
 					this.trailing_slash === 'always' &&
-					!info.path.split('/').pop().includes('.'));
+					!(info.path.split('/').pop() || '').includes('.'));
 
 			if (incorrect) {
 				info.path = has_trailing_slash ? info.path.slice(0, -1) : info.path + '/';
 				history.replaceState({}, '', `${this.base}${info.path}${location.search}`);
 			}
 		}
 
+		// @ts-ignore6
 		this.renderer.notify({
 			path: info.path,
 			query: info.query
 		});
 
+		// @ts-ignore
 		await this.renderer.update(info, chain, false);
 
 		if (!keepfocus) {

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

@@ -1,4 +1,4 @@
-/** @type {import('./router').Router} */
+/** @type {import('./router').Router?} */
 export let router;
 
 /** @type {string} */
@@ -7,7 +7,7 @@ export let base = '';
 /** @type {string} */
 export let assets = '/.';
 
-/** @param {import('./router').Router} _ */
+/** @param {import('./router').Router?} _ */
 export function init(_) {
 	router = _;
 }

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

@@ -30,13 +30,13 @@ export async function start({ paths, target, session, host, route, spa, trailing
 		throw new Error('Missing target element. See https://kit.svelte.dev/docs#configuration-target');
 	}
 
-	const router =
-		route &&
-		new Router({
-			base: paths.base,
-			routes,
-			trailing_slash
-		});
+	const router = route
+		? new Router({
+				base: paths.base,
+				routes,
+				trailing_slash
+		  })
+		: null;
 
 	const renderer = new Renderer({
 		Root,
@@ -50,9 +50,10 @@ export async function start({ paths, target, session, host, route, spa, trailing
 	set_paths(paths);
 
 	if (hydrate) await renderer.start(hydrate);
-	if (route) router.init(renderer);
-
-	if (spa) router.goto(location.href, { replaceState: true }, []);
+	if (router) {
+		router.init(renderer);
+		if (spa) router.goto(location.href, { replaceState: true }, []);
+	}
 
 	dispatchEvent(new CustomEvent('sveltekit:start'));
 }

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

@@ -26,47 +26,54 @@ export default async function render_route(request, route) {
 	/** @type {import('types/endpoint').RequestHandler} */
 	const handler = mod[request.method.toLowerCase().replace('delete', 'del')]; // 'delete' is a reserved word
 
-	if (handler) {
-		const match = route.pattern.exec(request.path);
-		const params = route.params(match);
-
-		const response = await handler({ ...request, params });
-		const preface = `Invalid response from route ${request.path}`;
-
-		if (response) {
-			if (typeof response !== 'object') {
-				return error(`${preface}: expected an object, got ${typeof response}`);
-			}
-
-			let { status = 200, body, headers = {} } = response;
-
-			headers = lowercase_keys(headers);
-			const type = headers['content-type'];
-
-			const is_type_textual = isContentTypeTextual(type);
-
-			if (!is_type_textual && !(body instanceof Uint8Array || is_string(body))) {
-				return error(
-					`${preface}: body must be an instance of string or Uint8Array if content-type is not a supported textual content-type`
-				);
-			}
-
-			/** @type {import('types/hooks').StrictBody} */
-			let normalized_body;
-
-			// ensure the body is an object
-			if (
-				(typeof body === 'object' || typeof body === 'undefined') &&
-				!(body instanceof Uint8Array) &&
-				(!type || type.startsWith('application/json'))
-			) {
-				headers = { ...headers, 'content-type': 'application/json; charset=utf-8' };
-				normalized_body = JSON.stringify(typeof body === 'undefined' ? {} : body);
-			} else {
-				normalized_body = /** @type {import('types/hooks').StrictBody} */ (body);
-			}
-
-			return { status, body: normalized_body, headers };
-		}
+	if (!handler) {
+		return error('no handler');
 	}
+
+	const match = route.pattern.exec(request.path);
+	if (!match) {
+		return error('could not parse parameters from request path');
+	}
+
+	const params = route.params(match);
+
+	const response = await handler({ ...request, params });
+	const preface = `Invalid response from route ${request.path}`;
+
+	if (!response) {
+		return error('no response');
+	}
+	if (typeof response !== 'object') {
+		return error(`${preface}: expected an object, got ${typeof response}`);
+	}
+
+	let { status = 200, body, headers = {} } = response;
+
+	headers = lowercase_keys(headers);
+	const type = headers['content-type'];
+
+	const is_type_textual = isContentTypeTextual(type);
+
+	if (!is_type_textual && !(body instanceof Uint8Array || is_string(body))) {
+		return error(
+			`${preface}: body must be an instance of string or Uint8Array if content-type is not a supported textual content-type`
+		);
+	}
+
+	/** @type {import('types/hooks').StrictBody} */
+	let normalized_body;
+
+	// ensure the body is an object
+	if (
+		(typeof body === 'object' || typeof body === 'undefined') &&
+		!(body instanceof Uint8Array) &&
+		(!type || type.startsWith('application/json'))
+	) {
+		headers = { ...headers, 'content-type': 'application/json; charset=utf-8' };
+		normalized_body = JSON.stringify(typeof body === 'undefined' ? {} : body);
+	} else {
+		normalized_body = /** @type {import('types/hooks').StrictBody} */ (body);
+	}
+
+	return { status, body: normalized_body, headers };
 }