Load RTE component only when needed (#9804)

Use react lazy to load rte component

src/components/views/rooms/wysiwyg_composer/DynamicImportWysiwygComposer.tsx

@@ -0,0 +1,36 @@
+/*
+Copyright 2022 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React, { ComponentProps, lazy, Suspense } from "react";
+
+const SendComposer = lazy(() => import("./SendWysiwygComposer"));
+const EditComposer = lazy(() => import("./EditWysiwygComposer"));
+
+export function DynamicImportSendWysiwygComposer(props: ComponentProps<typeof SendComposer>) {
+    return (
+        <Suspense fallback={<div />}>
+            <SendComposer {...props} />
+        </Suspense>
+    );
+}
+
+export function DynamicImportEditWysiwygComposer(props: ComponentProps<typeof EditComposer>) {
+    return (
+        <Suspense fallback={<div />}>
+            <EditComposer {...props} />
+        </Suspense>
+    );
+}

src/components/views/rooms/wysiwyg_composer/EditWysiwygComposer.tsx

@@ -43,32 +43,35 @@ interface EditWysiwygComposerProps {
     className?: string;
 }
 
-export function EditWysiwygComposer({ editorStateTransfer, className, ...props }: EditWysiwygComposerProps) {
+// Default needed for React.lazy
+export default function EditWysiwygComposer({ editorStateTransfer, className, ...props }: EditWysiwygComposerProps) {
     const initialContent = useInitialContent(editorStateTransfer);
     const isReady = !editorStateTransfer || initialContent !== undefined;
 
     const { editMessage, endEditing, onChange, isSaveDisabled } = useEditing(editorStateTransfer, initialContent);
 
+    if (!isReady) {
+        return null;
+    }
+
     return (
-        isReady && (
-            <WysiwygComposer
-                className={classNames("mx_EditWysiwygComposer", className)}
-                initialContent={initialContent}
-                onChange={onChange}
-                onSend={editMessage}
-                {...props}
-            >
-                {(ref) => (
-                    <>
-                        <Content disabled={props.disabled} ref={ref} />
-                        <EditionButtons
-                            onCancelClick={endEditing}
-                            onSaveClick={editMessage}
-                            isSaveDisabled={isSaveDisabled}
-                        />
-                    </>
-                )}
-            </WysiwygComposer>
-        )
+        <WysiwygComposer
+            className={classNames("mx_EditWysiwygComposer", className)}
+            initialContent={initialContent}
+            onChange={onChange}
+            onSend={editMessage}
+            {...props}
+        >
+            {(ref) => (
+                <>
+                    <Content disabled={props.disabled} ref={ref} />
+                    <EditionButtons
+                        onCancelClick={endEditing}
+                        onSaveClick={editMessage}
+                        isSaveDisabled={isSaveDisabled}
+                    />
+                </>
+            )}
+        </WysiwygComposer>
     );
 }

src/components/views/rooms/wysiwyg_composer/SendWysiwygComposer.tsx

@@ -49,7 +49,8 @@ interface SendWysiwygComposerProps {
     menuPosition: AboveLeftOf;
 }
 
-export function SendWysiwygComposer({
+// Default needed for React.lazy
+export default function SendWysiwygComposer({
     isRichTextEnabled,
     e2eStatus,
     menuPosition,

src/components/views/rooms/wysiwyg_composer/index.ts

@@ -14,6 +14,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-export { SendWysiwygComposer } from "./SendWysiwygComposer";
-export { EditWysiwygComposer } from "./EditWysiwygComposer";
+export {
+    DynamicImportSendWysiwygComposer as SendWysiwygComposer,
+    DynamicImportEditWysiwygComposer as EditWysiwygComposer,
+} from "./DynamicImportWysiwygComposer";
 export { sendMessage } from "./utils/message";

test/components/views/rooms/wysiwyg_composer/EditWysiwygComposer-test.tsx

@@ -64,13 +64,35 @@ describe("EditWysiwygComposer", () => {
         );
     };
 
+    it("Should not render the component when not ready", async () => {
+        // When
+        const { rerender } = customRender(false);
+        await waitFor(() => expect(screen.getByRole("textbox")).toHaveAttribute("contentEditable", "true"), {
+            timeout: 2000,
+        });
+
+        rerender(
+            <MatrixClientContext.Provider value={mockClient}>
+                <RoomContext.Provider value={{ ...defaultRoomContext, room: undefined }}>
+                    <EditWysiwygComposer disabled={false} editorStateTransfer={editorStateTransfer} />
+                </RoomContext.Provider>
+            </MatrixClientContext.Provider>,
+        );
+
+        // Then
+        await waitFor(() => expect(screen.queryByRole("textbox")).toBeNull());
+    });
+
     describe("Initialize with content", () => {
         it("Should initialize useWysiwyg with html content", async () => {
             // When
             customRender(false, editorStateTransfer);
-            await waitFor(() => expect(screen.getByRole("textbox")).toHaveAttribute("contentEditable", "true"));
 
             // Then
+            await waitFor(() => expect(screen.getByRole("textbox")).toHaveAttribute("contentEditable", "true"), {
+                timeout: 2000,
+            });
+
             await waitFor(() =>
                 expect(screen.getByRole("textbox")).toContainHTML(mockEvent.getContent()["formatted_body"]),
             );

test/components/views/rooms/wysiwyg_composer/SendWysiwygComposer-test.tsx

@@ -24,7 +24,7 @@ import defaultDispatcher from "../../../../../src/dispatcher/dispatcher";
 import { Action } from "../../../../../src/dispatcher/actions";
 import { IRoomState } from "../../../../../src/components/structures/RoomView";
 import { createTestClient, flushPromises, getRoomContext, mkEvent, mkStubRoom } from "../../../../test-utils";
-import { SendWysiwygComposer } from "../../../../../src/components/views/rooms/wysiwyg_composer";
+import { SendWysiwygComposer } from "../../../../../src/components/views/rooms/wysiwyg_composer/";
 import { aboveLeftOf } from "../../../../../src/components/structures/ContextMenu";
 import { ComposerInsertPayload, ComposerType } from "../../../../../src/dispatcher/payloads/ComposerInsertPayload";
 import { setSelection } from "../../../../../src/components/views/rooms/wysiwyg_composer/utils/selection";
@@ -101,12 +101,12 @@ describe("SendWysiwygComposer", () => {
         );
     };
 
-    it("Should render WysiwygComposer when isRichTextEnabled is at true", () => {
+    it("Should render WysiwygComposer when isRichTextEnabled is at true", async () => {
         // When
         customRender(jest.fn(), jest.fn(), false, true);
 
         // Then
-        expect(screen.getByTestId("WysiwygComposer")).toBeTruthy();
+        await waitFor(() => expect(screen.getByTestId("WysiwygComposer")).toBeTruthy());
     });
 
     it("Should render PlainTextComposer when isRichTextEnabled is at false", () => {