Added test (confirm.spec.js) for Redux Reducer file( confirm.js) (#5556)

Part of #2082

test/reducers/confirm.spec.js

@@ -0,0 +1,62 @@
+import deepFreeze from 'deep-freeze';
+import ui from '../../app/assets/javascripts/reducers/confirm';
+import { CONFIRMATION_INITIATED, ACTION_CONFIRMED, ACTION_CANCELLED } from '../../app/assets/javascripts/constants';
+import '../testHelper';
+
+const initialState = {
+    explanation: null,
+    confirmationActive: false,
+    confirmMessage: null,
+    onConfirm: null,
+    showInput: false,
+    warningMessage: null,
+  };
+
+describe('article_details reducer', () => {
+    test('should handle CONFIRMATION_INITIATED action by updating state', () => {
+          const action = {
+            type: CONFIRMATION_INITIATED,
+            explanation: 'Test explanation',
+            confirmationActive: true,
+            confirmMessage: 'Test confirm message',
+            onConfirm: jest.fn(),
+            showInput: true,
+            warningMessage: 'Test warning message',
+          };
+
+     const expectedState = {
+    explanation: 'Test explanation',
+    confirmationActive: true,
+    confirmMessage: 'Test confirm message',
+    onConfirm: expect.any(Function), // You can use expect.any(Function) for functions
+    showInput: true,
+    warningMessage: 'Test warning message',
+  };
+          deepFreeze(initialState);
+          const newState = ui(initialState, action);
+
+          expect(newState).toEqual(expectedState);
+    });
+
+  test('should handle ACTION_CONFIRMED action by resetting to initial state', () => {
+    const action = {
+      type: ACTION_CONFIRMED,
+    };
+
+    deepFreeze(initialState);
+    const expectedState = initialState;
+    const newState = ui(initialState, action);
+    expect(newState).toEqual(ui(undefined, expectedState));
+});
+
+test('should handle ACTION_CANCELLED action by resetting to initial state', () => {
+    const action = {
+      type: ACTION_CANCELLED,
+    };
+
+    deepFreeze(initialState);
+    const expectedState = initialState;
+    const newState = ui(initialState, action);
+    expect(newState).toEqual(ui(undefined, expectedState));
+});
+});