diff --git a/public/chat_flyout.test.tsx b/public/chat_flyout.test.tsx
new file mode 100644
index 00000000..85b00737
--- /dev/null
+++ b/public/chat_flyout.test.tsx
@@ -0,0 +1,149 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+
+import { ChatFlyout } from './chat_flyout';
+import * as chatContextExports from './contexts/chat_context';
+import { TAB_ID } from './utils/constants';
+
+jest.mock('./tabs/chat/chat_page', () => ({
+  ChatPage: () => <div aria-label="mock chat page" />,
+}));
+
+jest.mock('./tabs/chat_window_header', () => ({
+  ChatWindowHeader: () => <div aria-label="mock chat window header" />,
+}));
+
+jest.mock('./tabs/history/chat_history_page', () => ({
+  ChatHistoryPage: () => <div aria-label="mock chat history page" />,
+}));
+
+jest.mock('./components/agent_framework_traces_flyout_body', () => ({
+  AgentFrameworkTracesFlyoutBody: () => (
+    <div aria-label="mock agent framework traces flyout body" />
+  ),
+}));
+
+describe('<ChatFlyout />', () => {
+  beforeEach(() => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      selectedTabId: TAB_ID.CHAT,
+      traceId: 'chat_trace_id_mock',
+    });
+  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+  });
+
+  it('should only display chat panel when current tab is TAB_ID.CHAT under non-fullscreen mode', () => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      selectedTabId: TAB_ID.CHAT,
+      traceId: 'chat_trace_id_mock',
+    });
+
+    render(
+      <ChatFlyout
+        flyoutVisible={true}
+        overrideComponent={null}
+        flyoutProps={{}}
+        flyoutFullScreen={false}
+        toggleFlyoutFullScreen={jest.fn()}
+      />
+    );
+    expect(screen.getByLabelText('chat panel').classList).not.toContain('llm-chat-hidden');
+    expect(screen.getByLabelText('history panel').classList).toContain('llm-chat-hidden');
+  });
+
+  it('should only display history panel when current tab is TAB_ID.HISTORY under non-fullscreen mode', () => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      selectedTabId: TAB_ID.HISTORY,
+      traceId: 'chat_trace_id_mock',
+    });
+
+    render(
+      <ChatFlyout
+        flyoutVisible={true}
+        overrideComponent={null}
+        flyoutProps={{}}
+        flyoutFullScreen={false}
+        toggleFlyoutFullScreen={jest.fn()}
+      />
+    );
+    expect(screen.getByLabelText('chat panel').classList).toContain('llm-chat-hidden');
+    expect(screen.getByLabelText('history panel').classList).not.toContain('llm-chat-hidden');
+  });
+
+  it('should display chat history page', () => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      selectedTabId: TAB_ID.HISTORY,
+      traceId: 'chat_trace_id_mock',
+    });
+
+    render(
+      <ChatFlyout
+        flyoutVisible={true}
+        overrideComponent={null}
+        flyoutProps={{}}
+        flyoutFullScreen={false}
+        toggleFlyoutFullScreen={jest.fn()}
+      />
+    );
+
+    expect(screen.queryByLabelText('mock chat history page')).toBeInTheDocument();
+    expect(
+      screen.queryByLabelText('mock agent framework traces flyout body')
+    ).not.toBeInTheDocument();
+  });
+
+  it('should display traces page', () => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      selectedTabId: TAB_ID.TRACE,
+      traceId: 'chat_trace_id_mock',
+    });
+
+    render(
+      <ChatFlyout
+        flyoutVisible={true}
+        overrideComponent={null}
+        flyoutProps={{}}
+        flyoutFullScreen={false}
+        toggleFlyoutFullScreen={jest.fn()}
+      />
+    );
+
+    expect(screen.queryByLabelText('mock chat history page')).not.toBeInTheDocument();
+    expect(screen.queryByLabelText('mock agent framework traces flyout body')).toBeInTheDocument();
+  });
+
+  it('should always display chat panel when in fullscreen mode', () => {
+    jest.spyOn(chatContextExports, 'useChatContext').mockReturnValue({
+      setFlyoutVisible: jest.fn(),
+      // current tab is NOT chat
+      selectedTabId: TAB_ID.HISTORY,
+      traceId: 'chat_trace_id_mock',
+    });
+
+    render(
+      <ChatFlyout
+        flyoutVisible={true}
+        overrideComponent={null}
+        flyoutProps={{}}
+        flyoutFullScreen={true} // fullscreen
+        toggleFlyoutFullScreen={jest.fn()}
+      />
+    );
+
+    expect(screen.getByLabelText('chat panel').classList).not.toContain('llm-chat-hidden');
+    expect(screen.getByLabelText('history panel').classList).not.toContain('llm-chat-hidden');
+  });
+});
diff --git a/public/chat_flyout.tsx b/public/chat_flyout.tsx
index 42d6e32c..d4c2e234 100644
--- a/public/chat_flyout.tsx
+++ b/public/chat_flyout.tsx
@@ -5,7 +5,7 @@
 
 import { EuiFlyout, EuiFlyoutHeader, EuiResizableContainer } from '@elastic/eui';
 import cs from 'classnames';
-import React from 'react';
+import React, { useRef } from 'react';
 import { useChatContext } from './contexts/chat_context';
 import { ChatPage } from './tabs/chat/chat_page';
 import { ChatWindowHeader } from './tabs/chat_window_header';
@@ -13,8 +13,6 @@ import { ChatHistoryPage } from './tabs/history/chat_history_page';
 import { AgentFrameworkTracesFlyoutBody } from './components/agent_framework_traces_flyout_body';
 import { TAB_ID } from './utils/constants';
 
-let chatHistoryPageLoaded = false;
-
 interface ChatFlyoutProps {
   flyoutVisible: boolean;
   overrideComponent: React.ReactNode | null;
@@ -25,6 +23,7 @@ interface ChatFlyoutProps {
 
 export const ChatFlyout: React.FC<ChatFlyoutProps> = (props) => {
   const chatContext = useChatContext();
+  const chatHistoryPageLoadedRef = useRef(false);
 
   let chatPageVisible = false;
   let chatHistoryPageVisible = false;
@@ -54,7 +53,8 @@ export const ChatFlyout: React.FC<ChatFlyoutProps> = (props) => {
     chatPageVisible = true;
   }
 
-  if (!chatHistoryPageLoaded && chatHistoryPageVisible) chatHistoryPageLoaded = true;
+  if (!chatHistoryPageLoadedRef.current && chatHistoryPageVisible)
+    chatHistoryPageLoadedRef.current = true;
 
   const resizable = props.flyoutFullScreen && (chatHistoryPageVisible || chatTraceVisible);
   const getLeftPanelSize = () => {
@@ -107,6 +107,7 @@ export const ChatFlyout: React.FC<ChatFlyoutProps> = (props) => {
           {(Panel, Resizer) => (
             <>
               <Panel
+                aria-label="chat panel"
                 className={cs('llm-chat-horizontal-resize-panel', {
                   'llm-chat-hidden': leftPanelSize === 0,
                 })}
@@ -120,6 +121,7 @@ export const ChatFlyout: React.FC<ChatFlyoutProps> = (props) => {
               <>
                 {resizable && <Resizer />}
                 <Panel
+                  aria-label="history panel"
                   className={cs('llm-chat-horizontal-resize-panel', {
                     'llm-chat-hidden': leftPanelSize === 100,
                   })}
@@ -128,7 +130,7 @@ export const ChatFlyout: React.FC<ChatFlyoutProps> = (props) => {
                   initialSize={resizable ? 30 : undefined}
                   paddingSize="none"
                 >
-                  {chatHistoryPageLoaded && (
+                  {chatHistoryPageLoadedRef.current && (
                     <ChatHistoryPage
                       // refresh data when user switched to table from another tab
                       shouldRefresh={chatHistoryPageVisible}
diff --git a/public/components/core_visualization.test.tsx b/public/components/core_visualization.test.tsx
new file mode 100644
index 00000000..e9ad4d61
--- /dev/null
+++ b/public/components/core_visualization.test.tsx
@@ -0,0 +1,40 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import React from 'react';
+import { render, screen, fireEvent, waitFor } from '@testing-library/react';
+
+import * as coreContextExports from '../contexts/core_context';
+import { CoreVisualization } from './core_visualization';
+
+describe('<CoreVisualization />', () => {
+  beforeEach(() => {
+    jest.spyOn(coreContextExports, 'useCore').mockReturnValue({
+      services: {
+        uiSettings: {
+          get: jest.fn().mockReturnValue('MMM D, YYYY @ HH:mm:ss.SSS'),
+        },
+        startDeps: {
+          dashboard: {
+            DashboardContainerByValueRenderer: () => <div />,
+          },
+        },
+      },
+    });
+  });
+
+  afterEach(() => {
+    jest.resetAllMocks();
+  });
+
+  it('should display visualization of last 15 minutes by default', () => {
+    render(
+      <CoreVisualization
+        message={{ type: 'output', contentType: 'visualization', content: 'vis_id_mock' }}
+      />
+    );
+    expect(screen.queryByText('Last 15 minutes')).toBeInTheDocument();
+  });
+});