Added test suite

tests/emitter.spec.ts

@@ -0,0 +1,118 @@
+import {TypedEmitter} from '../src';
+
+describe('TypedEmitter', () => {
+	describe('Instance', () => {
+		type Events = {
+			foo: (data: string) => void;
+			bar: (x: number, y: number) => void;
+			'*': (event: string, ...args: any[]) => void;
+		};
+		let emitter: TypedEmitter<Events>;
+
+		beforeEach(() => {
+			emitter = new TypedEmitter<Events>();
+		});
+
+		it('calls the correct listener on emit', () => {
+			const fooHandler = jest.fn();
+			emitter.on('foo', fooHandler);
+
+			emitter.emit('foo', 'hello');
+			expect(fooHandler).toHaveBeenCalledWith('hello');
+		});
+
+		it('does NOT call listener after off', () => {
+			const fooHandler = jest.fn();
+			emitter.on('foo', fooHandler);
+			emitter.off('foo', fooHandler);
+			emitter.emit('foo', 'test');
+			expect(fooHandler).not.toHaveBeenCalled();
+		});
+
+		it('returns unsubscribe function that removes handler', () => {
+			const handler = jest.fn();
+			const unsubscribe = emitter.on('foo', handler);
+			unsubscribe();
+			emitter.emit('foo', 'x');
+			expect(handler).not.toHaveBeenCalled();
+		});
+
+		it('calls wildcard listener for all events', () => {
+			const wildcard = jest.fn();
+			emitter.on('*', wildcard);
+
+			emitter.emit('foo', 'data');
+			emitter.emit('bar', 1, 2);
+
+			expect(wildcard).toHaveBeenCalledWith('foo', 'data');
+			expect(wildcard).toHaveBeenCalledWith('bar', 1, 2);
+		});
+
+		it('once() resolves with argument and auto-unsubscribes', async () => {
+			const p = emitter.once('foo');
+			emitter.emit('foo', 'only-once');
+			expect(await p).toBe('only-once');
+
+			// no more handlers
+			const cb = jest.fn();
+			emitter.on('foo', cb);
+			emitter.emit('foo', 'again');
+			expect(cb).toHaveBeenCalledWith('again');
+		});
+
+		it('once() calls optional listener and Promise resolves', async () => {
+			const listener = jest.fn();
+			const oncePromise = emitter.once('bar', listener);
+
+			emitter.emit('bar', 1, 2);
+
+			expect(listener).toHaveBeenCalledWith(1, 2);
+			expect(await oncePromise).toEqual([1, 2]);
+		});
+	});
+
+	describe('Static', () => {
+		beforeEach(() => {
+			// Clear static listeners between tests
+			(TypedEmitter as any).listeners = {};
+		});
+
+		it('calls static listeners with emit', () => {
+			const spy = jest.fn();
+			TypedEmitter.on('event', spy);
+
+			TypedEmitter.emit('event', 1, 'a');
+			expect(spy).toHaveBeenCalledWith(1, 'a');
+		});
+
+		it('wildcard static listeners receive all event types', () => {
+			const spy = jest.fn();
+			TypedEmitter.on('*', spy);
+
+			TypedEmitter.emit('xy', 123);
+			expect(spy).toHaveBeenCalledWith('xy', 123);
+		});
+
+		it('only calls listener once with once()', async () => {
+			const handler = jest.fn();
+			const p = TypedEmitter.once('ping', handler);
+
+			TypedEmitter.emit('ping', 'pong');
+
+			expect(handler).toHaveBeenCalledWith('pong');
+			await expect(p).resolves.toBe('pong');
+
+			handler.mockClear();
+			TypedEmitter.emit('ping', 'other');
+			expect(handler).not.toHaveBeenCalled();
+		});
+
+		it('removes static listener with off', () => {
+			const h = jest.fn();
+			TypedEmitter.on('offevent', h);
+			TypedEmitter.off('offevent', h);
+			TypedEmitter.emit('offevent', 42);
+			expect(h).not.toHaveBeenCalled();
+		});
+	});
+});