fix: 🐛 Fix failing unit tests

Author: Ondřej Baše

Diff for: packages/integration-react/src/__mocks__/widgetMock.js

@@ -74,4 +74,23 @@ function widgetMockCleanup() {
   removeMerkur();
 }
 
-export { mockedWidgetProperties, widgetMockCleanup, widgetMockInit };
+function mockGlobalProperty(propName, value) {
+  const originalDescriptor = Object.getOwnPropertyDescriptor(global, propName);
+  Object.defineProperty(global, propName, { writable: true });
+  global[propName] = value;
+
+  return () => {
+    if (originalDescriptor) {
+      Object.defineProperty(global, propName, originalDescriptor);
+    } else {
+      delete global[propName];
+    }
+  };
+}
+
+export {
+  mockedWidgetProperties,
+  mockGlobalProperty,
+  widgetMockCleanup,
+  widgetMockInit,
+};

Diff for: packages/integration-react/src/__tests__/AbstractMerkurWidgetSpec.jsx

@@ -3,6 +3,7 @@ import { shallow } from 'enzyme';
 
 import {
   mockedWidgetProperties,
+  mockGlobalProperty,
   widgetMockCleanup,
   widgetMockInit,
 } from '../__mocks__/widgetMock';
@@ -27,6 +28,8 @@ describe('AbstractMerkurWidget', () => {
   let widgetProperties = null;
   let instance = null;
   let wrapper = null;
+  let restoreWindow;
+  let restoreDocument;
 
   beforeEach(() => {
     // Cache mocked widget data
@@ -47,6 +50,16 @@ describe('AbstractMerkurWidget', () => {
   afterEach(() => {
     widgetMockCleanup();
     jest.clearAllMocks();
+
+    if (restoreWindow) {
+      restoreWindow();
+      restoreWindow = null;
+    }
+
+    if (restoreDocument) {
+      restoreDocument();
+      restoreDocument = null;
+    }
   });
 
   describe('html getter', () => {
@@ -192,14 +205,14 @@ describe('AbstractMerkurWidget', () => {
 
   describe('_isClient() method', () => {
     it('should return false for non-browser environments', () => {
-      delete global.window;
+      restoreWindow = mockGlobalProperty('window', undefined);
 
       expect(instance._isClient()).toBe(false);
     });
 
     it('should return true for browser environments', () => {
-      global.window = {};
-      global.document = {};
+      restoreWindow = mockGlobalProperty('window', {});
+      restoreDocument = mockGlobalProperty('document', {});
 
       expect(instance._isClient()).toBe(true);
     });