Augment Writable<T> store interface with a get() method, and amend writable implementation accordingly

src/runtime/store/index.ts

@@ -28,6 +28,11 @@ export interface Readable<T> {
 
 /** Writable interface for both updating and subscribing. */
 export interface Writable<T> extends Readable<T> {
+	/**
+	 * Get value.
+	 */
+	get(): T;
+
 	/**
 	 * Set value and inform subscribers.
 	 * @param value to set
@@ -64,6 +69,10 @@ export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writa
 	let stop: Unsubscriber;
 	const subscribers: Array<SubscribeInvalidateTuple<T>> = [];
 
+	function get(): T {
+		return value;
+	}
+
 	function set(new_value: T): void {
 		if (safe_not_equal(value, new_value)) {
 			value = new_value;
@@ -99,7 +108,7 @@ export function writable<T>(value: T, start: StartStopNotifier<T> = noop): Writa
 		};
 	}
 
-	return { set, update, subscribe };
+	return { get, set, update, subscribe };
 }
 
 /** One or more `Readable`s. */

test/store/index.ts

@@ -19,6 +19,7 @@ describe('store', () => {
 			count.set(3);
 			count.update(n => n + 1);
 
+			assert.equal(count.get(), 4);
 			assert.deepEqual(values, [0, 1, 2]);
 		});