feat: add optional params for hash and searchParams to resolve()

.changeset/wicked-brooms-like.md

@@ -0,0 +1,6 @@
+---
+'@sveltejs/kit': minor
+---
+
+Adds optional arguments for URL params `hash` and `searchParams` to `resolve()` from `$app/paths`.
+Appends these to the returned URL after resolving the path.

packages/kit/src/runtime/app/paths/client.js

@@ -26,7 +26,9 @@ export function asset(file) {
 }
 
 /**
- * Resolve a pathname by prefixing it with the base path, if any, or resolve a route ID by populating dynamic segments with parameters.
+ * Resolve a pathname by prefixing it with the base path, if any,
+ * or resolve a route ID by populating dynamic segments with route parameters.
+ * Optionally accepts URL parameters and appends these to the resolved route.
  *
  * During server rendering, the base path is relative and depends on the page currently being rendered.
  *
@@ -37,10 +39,26 @@ export function asset(file) {
  * // using a pathname
  * const resolved = resolve(`/blog/hello-world`);
  *
- * // using a route ID plus parameters
+ * // using a route ID plus route parameters
  * const resolved = resolve('/blog/[slug]', {
  * 	slug: 'hello-world'
  * });
+ *
+ * // using a route ID plus URL parameters as Record
+ * const resolved = resolve('/blog/search',
+ * 	{ hash: 'results', searchParams: { author: 'John Doe', year: '2025' } }
+ * });
+ *
+ * // using a route ID plus URL parameters as URLSearchParams
+ * const resolved = resolve('/blog/search',
+ * 	{ hash: 'results', searchParams: new URLSearchParams({ author: 'John Doe', year: '2025' }) }
+ * });
+ *
+ * // using a route ID plus route parameters and URL parameters
+ * const resolved = resolve('/blog/[slug]',
+ * 	{ slug: 'hello-world' },
+ * 	{ hash: 'introduction' }
+ * });
  * ```
  * @since 2.26
  *
@@ -49,9 +67,58 @@ export function asset(file) {
  * @returns {ResolvedPathname}
  */
 export function resolve(...args) {
+	// args[0] is always the route ID or pathname
+	const routeID = /** @type {string} */ (args[0]);
+
+	/** @type {Record<string, string> | undefined} */
+	let routeParams;
+
+	/** @type {{ searchParams?: Record<string, string> | URLSearchParams; hash?: string } | undefined} */
+	let urlParams;
+
+	// Determine if args[1] is route params or URL params
+	if (args.length === 2) {
+		const searchParamsOrURLParams = args[1];
+		// If args[1] is actually undefined, we don't need to do anything
+		if (searchParamsOrURLParams) {
+			if ('searchParams' in searchParamsOrURLParams || 'hash' in searchParamsOrURLParams) {
+				// It's URL params
+				urlParams = searchParamsOrURLParams;
+			} else {
+				// Otherwise, it's route params
+				routeParams = /** @type {Record<string, string>} */ (searchParamsOrURLParams);
+			}
+		}
+	} else if (args.length === 3) {
+		// args[1] is route params, args[2] is URL params
+		routeParams = args[1];
+		urlParams = args[2];
+	}
+
 	// The type error is correct here, and if someone doesn't pass params when they should there's a runtime error,
-	// but we don't want to adjust the internal resolve_route function to accept `undefined`, hence the type cast.
-	return base + resolve_route(args[0], /** @type {Record<string, string>} */ (args[1]));
-}
+	// but we don't want to adjust the internal resolve_route function to accept undefined, hence the type cast.
+	let resolvedPath =
+		base + resolve_route(routeID, /** @type {Record<string, string>} */ (routeParams));
+
+	// Append searchParams and hash if provided. These do not affect route resolving.
+	if (urlParams?.searchParams) {
+		const { searchParams } = urlParams;
 
+		if (searchParams instanceof URLSearchParams) {
+			resolvedPath += `?${searchParams.toString()}`;
+		} else {
+			const query = new URLSearchParams();
+			for (const [key, value] of Object.entries(searchParams)) {
+				query.append(key, value);
+			}
+			resolvedPath += `?${query.toString()}`;
+		}
+	}
+
+	if (urlParams?.hash) {
+		resolvedPath += `#${urlParams.hash}`;
+	}
+
+	return resolvedPath;
+}
 export { base, assets, resolve as resolveRoute };

packages/kit/src/runtime/app/paths/types.d.ts

@@ -1,7 +1,7 @@
-import { Pathname, RouteId, RouteParams } from '$app/types';
+import { Pathname, ResolveURLParams, RouteId, RouteParams } from '$app/types';
 
 export type ResolveArgs<T extends RouteId | Pathname> = T extends RouteId
 	? RouteParams<T> extends Record<string, never>
-		? [route: T]
-		: [route: T, params: RouteParams<T>]
-	: [route: T];
+		? [route: T, options?: ResolveURLParams]
+		: [route: T, params: RouteParams<T>, options?: ResolveURLParams]
+	: [route: T, options?: ResolveURLParams];

packages/kit/src/types/ambient.d.ts

@@ -111,6 +111,15 @@ declare module '$app/types' {
 		? ReturnType<AppTypes['RouteParams']>[T]
 		: Record<string, never>;
 
+	/**
+	 * URL Parameters that can be optionally passed to the `resolve` function.
+	 * Used to specify a hash and/or search parameters to be included in the resolved URL.
+	 */
+	export type ResolveURLParams = {
+		hash?: string;
+		searchParams?: Record<string, string> | URLSearchParams;
+	};
+
 	/**
 	 * A utility for getting the parameters associated with a given layout, which is similar to `RouteParams` but also includes optional parameters for any child route.
 	 */

packages/kit/types/index.d.ts

@@ -3043,7 +3043,7 @@ declare module '$app/navigation' {
 }
 
 declare module '$app/paths' {
-	import type { RouteId, Pathname, ResolvedPathname, RouteParams, Asset } from '$app/types';
+	import type { RouteId, Pathname, ResolvedPathname, ResolveURLParams, RouteParams, Asset } from '$app/types';
 	/**
 	 * A string that matches [`config.kit.paths.base`](https://svelte.dev/docs/kit/configuration#paths).
 	 *
@@ -3070,9 +3070,9 @@ declare module '$app/paths' {
 	): ResolvedPathname;
 	type ResolveArgs<T extends RouteId | Pathname> = T extends RouteId
 		? RouteParams<T> extends Record<string, never>
-			? [route: T]
-			: [route: T, params: RouteParams<T>]
-		: [route: T];
+			? [route: T, options?: ResolveURLParams]
+			: [route: T, params: RouteParams<T>, options?: ResolveURLParams]
+		: [route: T, options?: ResolveURLParams];
 	/**
 	 * Resolve the URL of an asset in your `static` directory, by prefixing it with [`config.kit.paths.assets`](https://svelte.dev/docs/kit/configuration#paths) if configured, or otherwise by prefixing it with the base path.
 	 *
@@ -3091,7 +3091,9 @@ declare module '$app/paths' {
 	 * */
 	export function asset(file: Asset): string;
 	/**
-	 * Resolve a pathname by prefixing it with the base path, if any, or resolve a route ID by populating dynamic segments with parameters.
+	 * Resolve a pathname by prefixing it with the base path, if any,
+	 * or resolve a route ID by populating dynamic segments with route parameters.
+	 * Optionally accepts URL parameters and appends these to the resolved route.
 	 *
 	 * During server rendering, the base path is relative and depends on the page currently being rendered.
 	 *
@@ -3102,10 +3104,26 @@ declare module '$app/paths' {
 	 * // using a pathname
 	 * const resolved = resolve(`/blog/hello-world`);
 	 *
-	 * // using a route ID plus parameters
+	 * // using a route ID plus route parameters
 	 * const resolved = resolve('/blog/[slug]', {
 	 * 	slug: 'hello-world'
 	 * });
+	 *
+	 * // using a route ID plus URL parameters as Record
+	 * const resolved = resolve('/blog/search',
+	 * 	{ hash: 'results', searchParams: { author: 'John Doe', year: '2025' } }
+	 * });
+	 *
+	 * // using a route ID plus URL parameters as URLSearchParams
+	 * const resolved = resolve('/blog/search',
+	 * 	{ hash: 'results', searchParams: new URLSearchParams({ author: 'John Doe', year: '2025' }) }
+	 * });
+	 *
+	 * // using a route ID plus route parameters and URL parameters
+	 * const resolved = resolve('/blog/[slug]',
+	 * 	{ slug: 'hello-world' },
+	 * 	{ hash: 'introduction' }
+	 * });
 	 * ```
 	 * @since 2.26
 	 *
@@ -3481,6 +3499,15 @@ declare module '$app/types' {
 		? ReturnType<AppTypes['RouteParams']>[T]
 		: Record<string, never>;
 
+	/**
+	 * URL Parameters that can be optionally passed to the `resolve` function.
+	 * Used to specify a hash and/or search parameters to be included in the resolved URL.
+	 */
+	export type ResolveURLParams = {
+		hash?: string;
+		searchParams?: Record<string, string> | URLSearchParams;
+	};
+
 	/**
 	 * A utility for getting the parameters associated with a given layout, which is similar to `RouteParams` but also includes optional parameters for any child route.
 	 */