MM-50953 Post textbox cleanup (#23971)

* Remove unused code around scrollbarWidth

* MM-50953 Remove unused code for popover at mentions

* Add tests for messageHtmlToComponent wrapper

webapp/channels/src/plugins/export.js

@@ -45,7 +45,22 @@ window.Luxon = require('luxon');
 window.StyledComponents = require('styled-components');
 
 // Functions exposed on window for plugins to use.
-window.PostUtils = {formatText, messageHtmlToComponent};
+window.PostUtils = {
+    formatText,
+    messageHtmlToComponent: (html, ...otherArgs) => {
+        // Previously, this function took an extra isRHS argument as the second parameter. For backwards compatibility,
+        // support calling this as either messageHtmlToComponent(html, options) or messageHtmlToComponent(html, isRhs, options)
+
+        let options;
+        if (otherArgs.length === 2) {
+            options = otherArgs[1];
+        } else if (otherArgs.length === 1 && typeof otherArgs[0] === 'object') {
+            options = otherArgs[0];
+        }
+
+        return messageHtmlToComponent(html, options);
+    },
+};
 window.openInteractiveDialog = openInteractiveDialog;
 window.useNotifyAdmin = useNotifyAdmin;
 window.WebappUtils = {

webapp/channels/src/plugins/export.test.js

@@ -0,0 +1,38 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+import messageHtmlToComponent from 'utils/message_html_to_component';
+
+import './export';
+
+jest.mock('utils/message_html_to_component');
+
+describe('messageHtmlToComponent wrapper', () => {
+    const message = 'test';
+    const options = {emoji: true, images: false};
+    const isRHS = false;
+
+    test('should call messageHtmlToComponent properly with only message', () => {
+        window.PostUtils.messageHtmlToComponent(message);
+
+        expect(messageHtmlToComponent).toHaveBeenCalledWith(message, undefined);
+    });
+
+    test('should call messageHtmlToComponent properly with message and options', () => {
+        window.PostUtils.messageHtmlToComponent(message, options);
+
+        expect(messageHtmlToComponent).toHaveBeenCalledWith(message, options);
+    });
+
+    test('should call messageHtmlToComponent properly with only message when deprecated isRHS parameter is passed', () => {
+        window.PostUtils.messageHtmlToComponent(message, isRHS);
+
+        expect(messageHtmlToComponent).toHaveBeenCalledWith(message, undefined);
+    });
+
+    test('should call messageHtmlToComponent properly with message and options when deprecated isRHS parameter is passed', () => {
+        window.PostUtils.messageHtmlToComponent(message, isRHS, options);
+
+        expect(messageHtmlToComponent).toHaveBeenCalledWith(message, options);
+    });
+});

webapp/channels/src/plugins/test/__snapshots__/post_type.test.jsx.snap

@@ -84,7 +84,6 @@ exports[`plugins/PostMessageView should match snapshot with no extended post typ
           "onImageLoaded": [Function],
         }
       }
-      isRHS={false}
       mentionKeys={Array []}
       message="this is some text"
       options={Object {}}