From 6ff7abddd166c96be98d2af01826f136776728a6 Mon Sep 17 00:00:00 2001
From: Andrew Courtice <andrewcourtice@users.noreply.github.com>
Date: Thu, 9 Sep 2021 09:24:59 +1000
Subject: [PATCH] test(core): added event emitter test

---
 core/test/index.test.ts | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/core/test/index.test.ts b/core/test/index.test.ts
index 9b028125..6253e442 100644
--- a/core/test/index.test.ts
+++ b/core/test/index.test.ts
@@ -1,3 +1,7 @@
+import {
+    EventEmitter,
+} from '../src/event-emitter';
+
 import {
     createStore,
 } from '../src/index';
@@ -59,6 +63,31 @@ describe('Harlem Core', () => {
         store = getStore();
     });
 
+    describe('Event Emitter', () => {
+
+        test('Should handle on, once and emit', () => {
+            const eventEmitter = new EventEmitter();
+
+            const eventName = 'test-event';
+            const onListener = jest.fn();
+            const onceListener = jest.fn();
+
+            const listeners = [
+                eventEmitter.on(eventName, onListener),
+                eventEmitter.once(eventName, onceListener),
+            ];
+
+            eventEmitter.emit(eventName);
+            eventEmitter.emit(eventName);
+
+            expect(onListener).toHaveBeenCalledTimes(2);
+            expect(onceListener).toHaveBeenCalledTimes(1);
+
+            listeners.forEach(({ dispose }) => dispose());
+        });
+
+    });
+
     describe('Store', () => {
 
         test('Should prevent duplicate creation of store objects', () => {
@@ -107,7 +136,7 @@ describe('Harlem Core', () => {
                 state,
             } = store;
 
-            // @ts-expect-error
+            // @ts-expect-error This is readonly
             state.firstName = 'Billy';
 
             expect(state.firstName).toBe('John');