fix: add types for svelte/reactivity (#10817)

* fix: add types for svelte/reactivity - closes #10816

* simplify

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

.changeset/serious-needles-joke.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: add types for svelte/reactivity

packages/svelte/scripts/generate-types.js

@@ -29,6 +29,7 @@ await createBundle({
 		[`${pkg.name}/easing`]: `${dir}/src/easing/index.js`,
 		[`${pkg.name}/legacy`]: `${dir}/src/legacy/legacy-client.js`,
 		[`${pkg.name}/motion`]: `${dir}/src/motion/public.d.ts`,
+		[`${pkg.name}/reactivity`]: `${dir}/src/reactivity/index.js`,
 		[`${pkg.name}/server`]: `${dir}/src/server/index.js`,
 		[`${pkg.name}/store`]: `${dir}/src/store/public.d.ts`,
 		[`${pkg.name}/transition`]: `${dir}/src/transition/public.d.ts`,

packages/svelte/src/reactivity/date.js

@@ -55,14 +55,15 @@ const write = [
 	'setYear'
 ];
 
+var inited = false;
+
 export class ReactiveDate extends Date {
 	#raw_time = source(super.getTime());
-	static #inited = false;
 
 	// We init as part of the first instance so that we can treeshake this class
 	#init() {
-		if (!ReactiveDate.#inited) {
-			ReactiveDate.#inited = true;
+		if (!inited) {
+			inited = true;
 			const proto = ReactiveDate.prototype;
 			const date_proto = Date.prototype;
 

packages/svelte/types/index.d.ts

@@ -1806,6 +1806,48 @@ declare module 'svelte/motion' {
 	export function tweened<T>(value?: T | undefined, defaults?: TweenedOptions<T> | undefined): Tweened<T>;
 }
 
+declare module 'svelte/reactivity' {
+	export class Date extends Date {
+		
+		constructor(...values: any[]);
+		#private;
+	}
+	export class Set<T> extends Set<any> {
+		
+		constructor(value?: Iterable<T> | null | undefined);
+		
+		has(value: T): boolean;
+		
+		add(value: T): this;
+		
+		delete(value: T): boolean;
+		keys(): IterableIterator<T>;
+		values(): IterableIterator<T>;
+		entries(): IterableIterator<[T, T]>;
+		[Symbol.iterator](): IterableIterator<T>;
+		#private;
+	}
+	export class Map<K, V> extends Map<any, any> {
+		
+		constructor(value?: Iterable<readonly [K, V]> | null | undefined);
+		
+		has(key: K): boolean;
+		
+		forEach(callbackfn: (value: V, key: K, map: Map<K, V>) => void, this_arg?: any): void;
+		
+		get(key: K): V | undefined;
+		
+		set(key: K, value: V): this;
+		
+		delete(key: K): boolean;
+		keys(): IterableIterator<K>;
+		values(): IterableIterator<V>;
+		entries(): IterableIterator<[K, V]>;
+		[Symbol.iterator](): IterableIterator<[K, V]>;
+		#private;
+	}
+}
+
 declare module 'svelte/server' {
 	export function render(component: (...args: any[]) => void, options: {
 		props: Record<string, any>;