test: add unit tests for chat context

Signed-off-by: Lin Wang <wonglam@amazon.com>

public/contexts/__tests__/chat_context.test.tsx

@@ -0,0 +1,41 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import { renderHook } from '@testing-library/react-hooks';
+import { useChatContext, ChatContext } from '../chat_context';
+
+describe('useChatContext', () => {
+  it('should return chat context after useChatContext called', () => {
+    const chatContextValueMock = {
+      setSessionId: jest.fn(),
+      selectedTabId: 'chat' as const,
+      setSelectedTabId: jest.fn(),
+      flyoutVisible: true,
+      flyoutFullScreen: true,
+      setFlyoutVisible: jest.fn(),
+      setFlyoutComponent: jest.fn(),
+      userHasAccess: true,
+      contentRenderers: {},
+      actionExecutors: {},
+      currentAccount: { username: 'foo', tenant: '' },
+      setTitle: jest.fn(),
+      setTraceId: jest.fn(),
+    };
+    const { result } = renderHook(useChatContext, {
+      wrapper: ({ children }) => (
+        <ChatContext.Provider value={chatContextValueMock}>{children}</ChatContext.Provider>
+      ),
+    });
+
+    expect(result.current).toBe(chatContextValueMock);
+  });
+
+  it('should return error if context provider missed', () => {
+    const { result } = renderHook(useChatContext);
+
+    expect(result.error).toMatchInlineSnapshot(`[Error: ChatContext is not set]`);
+  });
+});