Add unit tests for utils (#5412)

* add unit tests for Card utils

* add unit tests for DateFnsLocale utils

* fix lint

* add unit tests for Events utils

* fix lint

* fix lint

src/utils/events.test.ts

@@ -0,0 +1,89 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import eventsUtils from './events';
+
+describe('Utils: events', () => {
+    describe('Method: on', () => {
+        it('should throw error if object is null', () => {
+            const call = () => eventsUtils.on(null, 'testEvent', vi.fn());
+
+            expect(call).toThrowError(new Error('obj cannot be null!'));
+        });
+
+        it('should init object callbacks with testEvent type if it does not exist', () => {
+            const obj = {};
+            const callback = vi.fn();
+
+            eventsUtils.on(obj, 'testEvent', callback);
+
+            expect(obj).toHaveProperty('_callbacks', {
+                testEvent: [callback]
+            });
+        });
+
+        it('should add callback to existing object callbacks', () => {
+            const initialCallback = vi.fn();
+            const obj = {
+                _callbacks: { testEvent: [initialCallback] }
+            };
+            const otherCallback = vi.fn();
+
+            eventsUtils.on(obj, 'testEvent', otherCallback);
+
+            expect(obj).toHaveProperty('_callbacks', {
+                testEvent: [initialCallback, otherCallback]
+            });
+        });
+    });
+
+    describe('Method: off', () => {
+        let obj: object;
+        let initialCallback: ReturnType<typeof vi.fn>;
+        beforeEach(() => {
+            initialCallback = vi.fn();
+            obj = {
+                _callbacks: {
+                    testEvent: [initialCallback]
+                }
+            };
+        });
+
+        it('should remove existing callbacks', () => {
+            eventsUtils.off(obj, 'testEvent', initialCallback);
+
+            expect(obj).toHaveProperty('_callbacks', { testEvent: [] });
+        });
+        it('should not remove callback if it is not registered for the given event', () => {
+            eventsUtils.off(obj, 'otherEvent', initialCallback);
+
+            expect(obj).toHaveProperty('_callbacks', {
+                testEvent: [initialCallback],
+                otherEvent: []
+            });
+        });
+        it('should not remove callback if it is not registered', () => {
+            const callbackToRemove = vi.fn();
+
+            eventsUtils.off(obj, 'testEvent', callbackToRemove);
+
+            expect(obj).toHaveProperty('_callbacks', {
+                testEvent: [initialCallback]
+            });
+        });
+    });
+
+    describe('Method: trigger', () => {
+        it('should trigger registered callback with given parameters', () => {
+            const obj = {};
+            const callback = vi.fn();
+            eventsUtils.on(obj, 'testEvent', callback);
+
+            eventsUtils.trigger(obj, 'testEvent', ['testValue1', 'testValue2']);
+
+            expect(callback).toHaveBeenCalledWith(
+                { type: 'testEvent' },
+                'testValue1',
+                'testValue2'
+            );
+        });
+    });
+});