[MM-57717] Convert SubMenuModal from Class Component to Function Component (#26902)

* Convert SubMenuModal from Class Component to Function Component

* Style fixes

* Review fixes

* Review fix

---------

Co-authored-by: Mattermost Build <build@mattermost.com>

webapp/channels/src/components/widgets/menu/menu_modals/submenu_modal/__snapshots__/submenu_modal.test.tsx.snap

@@ -33,6 +33,7 @@ exports[`components/submenu_modal should match snapshot 1`] = `
   <ModalBody
     bsClass="modal-body"
     componentClass="div"
+    data-testid="SubMenuModalBody"
     onClick={[Function]}
   >
     <MenuWrapper

webapp/channels/src/components/widgets/menu/menu_modals/submenu_modal/submenu_modal.test.tsx

@@ -1,10 +1,12 @@
 // Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
+import {fireEvent, waitForElementToBeRemoved} from '@testing-library/react';
 import {shallow} from 'enzyme';
 import React from 'react';
 import {Modal} from 'react-bootstrap';
 
+import {withIntl} from 'tests/helpers/intl-test-helper';
 import {render, screen, userEvent} from 'tests/react_testing_utils';
 
 import SubMenuModal from './submenu_modal';
@@ -55,14 +57,20 @@ describe('components/submenu_modal', () => {
         expect(wrapper).toMatchSnapshot();
     });
 
-    test('should match state when onHide is called', () => {
-        const wrapper = shallow<SubMenuModal>(
+    test('should hide on modal body click', async () => {
+        const view = render(withIntl(
             <SubMenuModal {...baseProps}/>,
-        );
+        ));
 
-        wrapper.setState({show: true});
-        wrapper.instance().onHide();
-        expect(wrapper.state('show')).toEqual(false);
+        screen.getByText('Text A');
+        screen.getByText('Text B');
+        screen.getByText('Text C');
+
+        fireEvent.click(view.getByTestId('SubMenuModalBody'));
+
+        await waitForElementToBeRemoved(() => screen.getByText('Text A'));
+        expect(screen.queryAllByText('Text B').length).toBe(0);
+        expect(screen.queryAllByText('Text C').length).toBe(0);
     });
 
     test('should have called click function when button is clicked', async () => {

webapp/channels/src/components/widgets/menu/menu_modals/submenu_modal/submenu_modal.tsx

@@ -1,10 +1,9 @@
 // Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
 // See LICENSE.txt for license information.
 
-import React from 'react';
+import React, {useCallback, useMemo, useState} from 'react';
 import {Modal} from 'react-bootstrap';
-
-import * as Utils from 'utils/utils';
+import {useIntl} from 'react-intl';
 
 import Menu from '../../menu';
 import type SubMenuItem from '../../menu_items/submenu_item';
@@ -17,63 +16,61 @@ type Props = {
     onExited: () => void;
 }
 
-type State = {
-    show: boolean;
-}
+const SubMenuModal = ({
+    elements,
+    onExited,
+}: Props) => {
+    const [show, setShow] = useState(true);
+    const intl = useIntl();
 
-export default class SubMenuModal extends React.PureComponent<Props, State> {
-    public constructor(props: Props) {
-        super(props);
-        this.state = {
-            show: true,
-        };
-    }
+    const onHide = useCallback(() => {
+        setShow(false);
+    }, []);
 
-    public onHide = () => { //public because it is used on tests
-        this.setState({show: false});
-    };
-
-    public render() {
-        let SubMenuItems;
-        if (this.props.elements) {
-            SubMenuItems = this.props.elements.map((element) => {
-                return (
-                    <Menu.ItemSubMenu
-                        key={element.id}
-                        id={element.id}
-                        text={element.text}
-                        subMenu={element.subMenu}
-                        action={element.action}
-                        filter={element.filter}
-                        root={false}
-                    />
-                );
-            });
+    const subMenuItems = useMemo(() => {
+        if (!elements) {
+            return undefined;
         }
-        return (
-            <Modal
-                dialogClassName={'SubMenuModal a11y__modal mobile-sub-menu'}
-                show={this.state.show}
-                onHide={this.onHide}
-                onExited={this.props.onExited}
-                enforceFocus={false}
-                id='submenuModal'
-                role='dialog'
-            >
-                <Modal.Body
-                    onClick={this.onHide}
-                >
-                    <MenuWrapper>
-                        <Menu
-                            openLeft={true}
-                            ariaLabel={Utils.localizeMessage('post_info.submenu.mobile', 'mobile submenu').toLowerCase()}
-                        >
-                            {SubMenuItems}
-                        </Menu>
-                        <div/>
-                    </MenuWrapper>
-                </Modal.Body>
-            </Modal>
+        return elements.map(
+            (element) => (
+                <Menu.ItemSubMenu
+                    key={element.id}
+                    id={element.id}
+                    text={element.text}
+                    subMenu={element.subMenu}
+                    action={element.action}
+                    filter={element.filter}
+                    root={false}
+                />),
         );
-    }
-}
+    }, [elements]);
+
+    return (
+        <Modal
+            dialogClassName={'SubMenuModal a11y__modal mobile-sub-menu'}
+            show={show}
+            onHide={onHide}
+            onExited={onExited}
+            enforceFocus={false}
+            id='submenuModal'
+            role='dialog'
+        >
+            <Modal.Body
+                data-testid={'SubMenuModalBody'}
+                onClick={onHide}
+            >
+                <MenuWrapper>
+                    <Menu
+                        openLeft={true}
+                        ariaLabel={intl.formatMessage({id: 'post_info.submenu.mobile', defaultMessage: 'mobile submenu'})}
+                    >
+                        {subMenuItems}
+                    </Menu>
+                    <div/>
+                </MenuWrapper>
+            </Modal.Body>
+        </Modal>
+    );
+};
+
+export default React.memo(SubMenuModal);