[CLNP-5043] Add unit tests for improved MessageSearch module (#1228)

https://sendbird.atlassian.net/browse/CLNP-5043 
Two things are handled based on what I mentioned in
https://sendbird.atlassian.net/wiki/spaces/UIKitreact/pages/2511765635/UIKit+React+new+State+Management+Method+Proposal#4.1-Unit-Test
- [x] Added unit tests for `useMessageSearch` hook and new
`MessageSearchProvider`
- [x] Added integration tests for `MessageSearchUI` component

So the MessageSearch module test coverage has been changed 
**from** 
File --------------------------------------------------| % Stmts | %
Branch | % Funcs | % Lines | Uncovered Line #s
<img width="814" alt="Screenshot 2024-10-08 at 2 36 55 PM"
src="https://github.com/user-attachments/assets/c0fef6fe-0fc1-4f37-b74f-0486d70352a7">
**to** 
<img width="941" alt="after"
src="https://github.com/user-attachments/assets/7fc19fb8-810c-4256-8230-3884d11e109a">
note that it used to be like 0%, but now the test coverage of the newly
added files is almost 100%; green 🟩.



### Checklist

Put an `x` in the boxes that apply. You can also fill these out after
creating the PR. If unsure, ask the members.
This is a reminder of what we look for before merging your code.

- [x] **All tests pass locally with my changes**
- [x] **I have added tests that prove my fix is effective or that my
feature works**
- [ ] **Public components / utils / props are appropriately exported**
- [ ] I have added necessary documentation (if appropriate)

src/modules/MessageSearch/__test__/MessageSearchUI.integration.test.tsx

@@ -0,0 +1,151 @@
+import React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+import '@testing-library/jest-dom/extend-expect';
+import MessageSearchUI from '../components/MessageSearchUI';
+import { LocalizationContext } from '../../../lib/LocalizationContext';
+import * as useMessageSearchModule from '../context/hooks/useMessageSearch';
+
+jest.mock('../context/hooks/useMessageSearch');
+
+const mockStringSet = {
+  SEARCH_IN: 'Search in',
+  SEARCH_PLACEHOLDER: 'Search',
+  SEARCHING: 'Searching...',
+  NO_SEARCHED_MESSAGE: 'No results found',
+  NO_TITLE: 'No title',
+  PLACE_HOLDER__RETRY_TO_CONNECT: 'Retry',
+};
+
+const mockLocalizationContext = {
+  stringSet: mockStringSet,
+};
+
+const defaultMockState = {
+  isQueryInvalid: false,
+  searchString: '',
+  requestString: '',
+  currentChannel: null,
+  loading: false,
+  scrollRef: { current: null },
+  hasMoreResult: false,
+  onScroll: jest.fn(),
+  allMessages: [],
+  onResultClick: jest.fn(),
+  selectedMessageId: null,
+};
+
+const defaultMockActions = {
+  setSelectedMessageId: jest.fn(),
+  handleRetryToConnect: jest.fn(),
+};
+
+describe('MessageSearchUI Integration Tests', () => {
+  const mockUseMessageSearch = useMessageSearchModule.default as jest.Mock;
+
+  const renderComponent = (mockState = {}, mockActions = {}) => {
+    mockUseMessageSearch.mockReturnValue({
+      state: { ...defaultMockState, ...mockState },
+      actions: { ...defaultMockActions, ...mockActions },
+    });
+
+    return render(
+      <LocalizationContext.Provider value={mockLocalizationContext as any}>
+        <MessageSearchUI />
+      </LocalizationContext.Provider>,
+    );
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('renders initial state correctly', () => {
+    renderComponent();
+    expect(screen.getByText('Search in')).toBeInTheDocument();
+  });
+
+  it('displays loading state when search is in progress', () => {
+    renderComponent({ loading: true, searchString: 'test query', requestString: 'test query' });
+    expect(screen.getByText(mockStringSet.SEARCHING)).toBeInTheDocument();
+  });
+
+  it('displays search results when available', () => {
+    renderComponent({
+      allMessages: [
+        { messageId: 1, message: 'Message 1', sender: { nickname: 'Sender 1' } },
+        { messageId: 2, message: 'Message 2', sender: { nickname: 'Sender 2' } },
+      ],
+      searchString: 'test query',
+    });
+    expect(screen.getByText('Message 1')).toBeInTheDocument();
+    expect(screen.getByText('Message 2')).toBeInTheDocument();
+  });
+
+  it('handles no results state', () => {
+    renderComponent({ allMessages: [], searchString: 'no results query', requestString: 'no results query' });
+    expect(screen.getByText(mockStringSet.NO_SEARCHED_MESSAGE)).toBeInTheDocument();
+  });
+
+  it('handles error state and retry', async () => {
+    const handleRetryToConnect = jest.fn();
+    renderComponent(
+      { isQueryInvalid: true, searchString: 'error query', requestString: 'error query' },
+      { handleRetryToConnect },
+    );
+    expect(screen.getByText(mockStringSet.PLACE_HOLDER__RETRY_TO_CONNECT)).toBeInTheDocument();
+
+    const retryButton = screen.getByText('Retry');
+    fireEvent.click(retryButton);
+
+    expect(handleRetryToConnect).toHaveBeenCalled();
+  });
+
+  it('triggers loading more messages when scrolled near bottom', async () => {
+    const onScroll = jest.fn();
+    const loadMoreMessages = jest.fn();
+    const { container } = renderComponent({
+      allMessages: [{ messageId: 1, message: 'Message 1' }],
+      hasMoreResult: true,
+      onScroll,
+    });
+
+    const scrollContainer = container.firstChild as Element;
+
+    // define scroll container properties
+    Object.defineProperty(scrollContainer, 'scrollHeight', { configurable: true, value: 300 });
+    Object.defineProperty(scrollContainer, 'clientHeight', { configurable: true, value: 500 });
+    Object.defineProperty(scrollContainer, 'scrollTop', { configurable: true, value: 450 });
+
+    const handleScroll = (e: React.UIEvent<HTMLDivElement>) => {
+      const { scrollTop, scrollHeight, clientHeight } = e.currentTarget;
+
+      if (scrollTop + clientHeight >= scrollHeight - 1) {
+        loadMoreMessages();
+      }
+    };
+
+    fireEvent.scroll(scrollContainer);
+    handleScroll({ currentTarget: scrollContainer } as React.UIEvent<HTMLDivElement>);
+
+    expect(loadMoreMessages).toHaveBeenCalled();
+  });
+
+  it('handles message click', () => {
+    const setSelectedMessageId = jest.fn();
+    const onResultClick = jest.fn();
+    renderComponent(
+      {
+        allMessages: [{ messageId: 1, message: 'Message 1', sender: { nickname: 'Sender 1' } }],
+        searchString: 'Message 1',
+        onResultClick,
+      },
+      { setSelectedMessageId },
+    );
+
+    const message = screen.getByText('Message 1');
+    fireEvent.click(message);
+
+    expect(setSelectedMessageId).toHaveBeenCalledWith(1);
+    expect(onResultClick).toHaveBeenCalled();
+  });
+});

src/modules/MessageSearch/components/MessageSearchUI/index.tsx

@@ -35,7 +35,7 @@ export const MessageSearchUI: React.FC<MessageSearchUIProps> = ({
 }: MessageSearchUIProps) => {
   const {
     state: {
-      isInvalid,
+      isQueryInvalid,
       searchString,
       requestString,
       currentChannel,
@@ -83,7 +83,7 @@ export const MessageSearchUI: React.FC<MessageSearchUIProps> = ({
     return stringSet.NO_TITLE;
   };
 
-  if (isInvalid && searchString && requestString) {
+  if (isQueryInvalid && searchString && requestString) {
     return renderPlaceHolderError?.() || (
       <div className="sendbird-message-search">
         <PlaceHolder

src/modules/MessageSearch/context/MessageSearchProvider.tsx

@@ -28,7 +28,7 @@ export interface MessageSearchState extends MessageSearchProviderProps {
   channelUrl: string;
   allMessages: ClientSentMessages[];
   loading: boolean;
-  isInvalid: boolean;
+  isQueryInvalid: boolean;
   initialized: boolean;
   currentChannel: GroupChannel | null;
   currentMessageSearchQuery: MessageSearchQuery | null;
@@ -45,7 +45,7 @@ const initialState: MessageSearchState = {
   channelUrl: '',
   allMessages: [],
   loading: false,
-  isInvalid: false,
+  isQueryInvalid: false,
   initialized: false,
   currentChannel: null,
   currentMessageSearchQuery: null,