typescript version of store

.gitignore

@@ -6,7 +6,7 @@ node_modules
 /compiler.js
 /index.js
 /internal.*
-/store.js
+/store.*
 /easing.js
 /motion.*
 /transition.js

package.json

@@ -31,7 +31,8 @@
     "dev": "rollup -cw",
     "pretest": "npm run build",
     "posttest": "agadoo src/internal/index.js",
-    "prepublishOnly": "export PUBLISH=true && npm run lint && npm test"
+    "prepublishOnly": "export PUBLISH=true && npm run lint && npm test",
+    "tsd": "tsc -d src/store.ts --outDir ."
   },
   "repository": {
     "type": "git",

rollup.config.js

@@ -87,8 +87,37 @@ export default [
 		external: id => id.startsWith('svelte/')
 	},
 
+	/* store.mjs */
+	{
+		input: `src/store.ts`,
+		output: [
+			{
+				file: `store.mjs`,
+				format: 'esm',
+				paths: id => id.startsWith('svelte/') && id.replace('svelte', '.')
+			},
+			{
+				file: `store.js`,
+				format: 'cjs',
+				paths: id => id.startsWith('svelte/') && id.replace('svelte', '.')
+			}
+		],
+		plugins: [
+			is_publish
+				? typescript({
+					include: 'src/**',
+					exclude: 'src/internal/**',
+					typescript: require('typescript')
+				})
+				: sucrase({
+					transforms: ['typescript']
+				})
+		],
+		external: id => id.startsWith('svelte/')
+	},
+
 	// everything else
-	...['index', 'store', 'easing', 'transition', 'animate'].map(name => ({
+	...['index', 'easing', 'transition', 'animate'].map(name => ({
 		input: `${name}.mjs`,
 		output: {
 			file: `${name}.js`,

src/store.ts

@@ -0,0 +1,130 @@
+import { run_all, noop, safe_not_equal } from './internal/utils';
+
+type Subscriber<T> = (value: T) => void;
+
+type Unsubscriber = () => void;
+
+type Updater<T> = (value: T) => T;
+
+type Invalidater<T> = (value?: T) => void;
+
+type StartStopNotifier<T> = (set: Subscriber<T>) => Unsubscriber | void;
+
+export interface ReadableStore<T> {
+	subscribe(run: Subscriber<T>, invalidate?: Invalidater<T>): Unsubscriber;
+}
+
+export interface WritableStore<T> extends ReadableStore<T> {
+	set(value: T): void;
+	update(updater: Updater<T>): void;
+}
+
+type SubscribeInvalidateTuple<T> = [Subscriber<T>, Invalidater<T>];
+
+export function readable<T>(value: T, start: StartStopNotifier<T>): ReadableStore<T> {
+	return {
+		subscribe: writable(value, start).subscribe,
+	};
+}
+
+export function writable<T>(value: T, start: StartStopNotifier<T> = noop): WritableStore<T> {
+	let stop: Unsubscriber;
+	const subscribers: Array<SubscribeInvalidateTuple<T>> = [];
+
+	function set(new_value: T): void {
+		if (safe_not_equal(value, new_value)) {
+			value = new_value;
+			if (!stop) {
+				return; // not ready
+			}
+			subscribers.forEach((s) => s[1]());
+			subscribers.forEach((s) => s[0](value));
+		}
+	}
+
+	function update(fn: Updater<T>): void {
+		set(fn(value));
+	}
+
+	function subscribe(run: Subscriber<T>, invalidate: Invalidater<T> = noop): Unsubscriber {
+		const subscriber: SubscribeInvalidateTuple<T> = [run, invalidate];
+		subscribers.push(subscriber);
+		if (subscribers.length === 1) {
+			stop = start(set) || noop;
+		}
+		run(value);
+
+		return () => {
+			const index = subscribers.indexOf(subscriber);
+			if (index !== -1) {
+				subscribers.splice(index, 1);
+			}
+			if (subscribers.length === 0) {
+				stop();
+			}
+		};
+	}
+
+	return { set, update, subscribe };
+}
+
+export function derived<T>(
+	stores: ReadableStore<T> | Array<ReadableStore<T>>,
+	fn: (values: T | T[], set?: Subscriber<T>) => T | Unsubscriber | void,
+	initial_value: T): ReadableStore<T> {
+
+	const single = !Array.isArray(stores);
+	const stores_array: Array<ReadableStore<T>> = single
+		? [stores as ReadableStore<T>]
+		: stores as Array<ReadableStore<T>>;
+
+	const auto = fn.length < 2;
+
+	return readable(initial_value, (set) => {
+		let inited = false;
+		const values: T[] = [];
+
+		let pending = 0;
+		let cleanup = noop;
+
+		const sync = () => {
+			if (pending) {
+				return;
+			}
+			cleanup();
+			const result = fn(single ? values[0] : values, set);
+			if (auto) {
+				set(result as T);
+			} else {
+				cleanup = result as Unsubscriber || noop;
+			}
+		};
+
+		const unsubscribers = stores_array.map((store, i) => store.subscribe(
+			(value) => {
+				values[i] = value;
+				pending &= ~(1 << i);
+				if (inited) {
+					sync();
+				}
+			},
+			() => {
+				pending |= (1 << i);
+			}),
+		);
+
+		inited = true;
+		sync();
+
+		return function stop() {
+			run_all(unsubscribers);
+			cleanup();
+		};
+	});
+}
+
+export function get<T>(store: ReadableStore<T>): T {
+	let value: T | undefined;
+	store.subscribe((_: T) => value = _)();
+	return value as T;
+}

store.mjs

@@ -1,85 +0,0 @@
-import { run_all, noop, get_store_value, safe_not_equal } from './internal';
-
-export function readable(value, start) {
-	return {
-		subscribe: writable(value, start).subscribe
-	};
-}
-
-export function writable(value, start = noop) {
-	let stop;
-	const subscribers = [];
-
-	function set(new_value) {
-		if (safe_not_equal(value, new_value)) {
-			value = new_value;
-			if (!stop) return; // not ready
-			subscribers.forEach(s => s[1]());
-			subscribers.forEach(s => s[0](value));
-		}
-	}
-
-	function update(fn) {
-		set(fn(value));
-	}
-
-	function subscribe(run, invalidate = noop) {
-		const subscriber = [run, invalidate];
-		subscribers.push(subscriber);
-		if (subscribers.length === 1) stop = start(set) || noop;
-		run(value);
-
-		return () => {
-			const index = subscribers.indexOf(subscriber);
-			if (index !== -1) subscribers.splice(index, 1);
-			if (subscribers.length === 0) stop();
-		};
-	}
-
-	return { set, update, subscribe };
-}
-
-export function derived(stores, fn, initial_value) {
-	const single = !Array.isArray(stores);
-	if (single) stores = [stores];
-
-	const auto = fn.length < 2;
-	let value = {};
-
-	return readable(initial_value, set => {
-		let inited = false;
-		const values = [];
-
-		let pending = 0;
-		let cleanup = noop;
-
-		const sync = () => {
-			if (pending) return;
-			cleanup();
-			const result = fn(single ? values[0] : values, set);
-			if (auto) set(result);
-			else cleanup = result || noop;
-		};
-
-		const unsubscribers = stores.map((store, i) => store.subscribe(
-			value => {
-				values[i] = value;
-				pending &= ~(1 << i);
-				if (inited) sync();
-			},
-			() => {
-				pending |= (1 << i);
-			})
-		);
-
-		inited = true;
-		sync();
-
-		return function stop() {
-			run_all(unsubscribers);
-			cleanup();
-		};
-	});
-}
-
-export { get_store_value as get };

tsconfig.json

@@ -7,7 +7,8 @@
         "allowJs": true,
         "lib": ["es5", "es6", "dom"],
         "importHelpers": true,
-        "moduleResolution": "node"
+        "moduleResolution": "node",
+        "strict": true
     },
     "include": [
         "src"