From db2e958823ef1cce5b860f910fc782a19ef28093 Mon Sep 17 00:00:00 2001
From: David Langley <langley.dave@gmail.com>
Date: Wed, 17 Sep 2025 12:47:20 +0100
Subject: [PATCH] Disable RTE formatting buttons when the content contains a
 slash command (#30802)

* Add ability to disable all formatting buttons

* Create hook to check if the content contains a slash command

* Disable the formatting buttons if the message content contains a slash command

* lint

* typo
---
 .../components/FormattingButtons.tsx          |  31 ++--
 .../components/WysiwygComposer.tsx            |   6 +-
 .../hooks/useContainsCommand.ts               |  53 ++++++
 .../components/FormattingButtons-test.tsx     |  10 ++
 .../components/WysiwygComposer-test.tsx       |  19 +++
 .../hooks/useContainsCommand-test.tsx         | 161 ++++++++++++++++++
 6 files changed, 266 insertions(+), 14 deletions(-)
 create mode 100644 src/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand.ts
 create mode 100644 test/unit-tests/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand-test.tsx

diff --git a/src/components/views/rooms/wysiwyg_composer/components/FormattingButtons.tsx b/src/components/views/rooms/wysiwyg_composer/components/FormattingButtons.tsx
index 27301110f3..15d6405d87 100644
--- a/src/components/views/rooms/wysiwyg_composer/components/FormattingButtons.tsx
+++ b/src/components/views/rooms/wysiwyg_composer/components/FormattingButtons.tsx
@@ -43,6 +43,7 @@ function Button({ label, keyCombo, onClick, actionState, icon }: ButtonProps): J
             element="button"
             onClick={onClick as (e: ButtonEvent) => void}
             aria-label={label}
+            disabled={actionState === "disabled"}
             className={classNames("mx_FormattingButtons_Button", {
                 mx_FormattingButtons_active: actionState === "reversed",
                 mx_FormattingButtons_Button_hover: actionState === "enabled",
@@ -64,55 +65,59 @@ function Button({ label, keyCombo, onClick, actionState, icon }: ButtonProps): J
 interface FormattingButtonsProps {
     composer: FormattingFunctions;
     actionStates: AllActionStates;
+    /**
+     * Whether all buttons should be disabled
+     */
+    disabled?: boolean;
 }
 
-export function FormattingButtons({ composer, actionStates }: FormattingButtonsProps): JSX.Element {
+export function FormattingButtons({ composer, actionStates, disabled }: FormattingButtonsProps): JSX.Element {
     const composerContext = useComposerContext();
     const isInList = actionStates.unorderedList === "reversed" || actionStates.orderedList === "reversed";
     return (
         <div className="mx_FormattingButtons">
             <Button
-                actionState={actionStates.bold}
+                actionState={disabled ? "disabled" : actionStates.bold}
                 label={_t("composer|format_bold")}
                 keyCombo={{ ctrlOrCmdKey: true, key: "b" }}
                 onClick={() => composer.bold()}
                 icon={<BoldIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.italic}
+                actionState={disabled ? "disabled" : actionStates.italic}
                 label={_t("composer|format_italic")}
                 keyCombo={{ ctrlOrCmdKey: true, key: "i" }}
                 onClick={() => composer.italic()}
                 icon={<ItalicIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.underline}
+                actionState={disabled ? "disabled" : actionStates.underline}
                 label={_t("composer|format_underline")}
                 keyCombo={{ ctrlOrCmdKey: true, key: "u" }}
                 onClick={() => composer.underline()}
                 icon={<UnderlineIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.strikeThrough}
+                actionState={disabled ? "disabled" : actionStates.strikeThrough}
                 label={_t("composer|format_strikethrough")}
                 onClick={() => composer.strikeThrough()}
                 icon={<StrikeThroughIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.unorderedList}
+                actionState={disabled ? "disabled" : actionStates.unorderedList}
                 label={_t("composer|format_unordered_list")}
                 onClick={() => composer.unorderedList()}
                 icon={<BulletedListIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.orderedList}
+                actionState={disabled ? "disabled" : actionStates.orderedList}
                 label={_t("composer|format_ordered_list")}
                 onClick={() => composer.orderedList()}
                 icon={<NumberedListIcon className="mx_FormattingButtons_Icon" />}
             />
             {isInList && (
                 <Button
-                    actionState={actionStates.indent}
+                    actionState={disabled ? "disabled" : actionStates.indent}
                     label={_t("composer|format_increase_indent")}
                     onClick={() => composer.indent()}
                     icon={<IndentIcon className="mx_FormattingButtons_Icon" />}
@@ -120,33 +125,33 @@ export function FormattingButtons({ composer, actionStates }: FormattingButtonsP
             )}
             {isInList && (
                 <Button
-                    actionState={actionStates.unindent}
+                    actionState={disabled ? "disabled" : actionStates.unindent}
                     label={_t("composer|format_decrease_indent")}
                     onClick={() => composer.unindent()}
                     icon={<UnIndentIcon className="mx_FormattingButtons_Icon" />}
                 />
             )}
             <Button
-                actionState={actionStates.quote}
+                actionState={disabled ? "disabled" : actionStates.quote}
                 label={_t("action|quote")}
                 onClick={() => composer.quote()}
                 icon={<QuoteIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.inlineCode}
+                actionState={disabled ? "disabled" : actionStates.inlineCode}
                 label={_t("composer|format_inline_code")}
                 keyCombo={{ ctrlOrCmdKey: true, key: "e" }}
                 onClick={() => composer.inlineCode()}
                 icon={<InlineCodeIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.codeBlock}
+                actionState={disabled ? "disabled" : actionStates.codeBlock}
                 label={_t("composer|format_code_block")}
                 onClick={() => composer.codeBlock()}
                 icon={<CodeBlockIcon className="mx_FormattingButtons_Icon" />}
             />
             <Button
-                actionState={actionStates.link}
+                actionState={disabled ? "disabled" : actionStates.link}
                 label={_t("composer|format_link")}
                 onClick={() => openLinkModal(composer, composerContext, actionStates.link === "reversed")}
                 icon={<LinkIcon className="mx_FormattingButtons_Icon" />}
diff --git a/src/components/views/rooms/wysiwyg_composer/components/WysiwygComposer.tsx b/src/components/views/rooms/wysiwyg_composer/components/WysiwygComposer.tsx
index 4c8ba0834f..10b13a3523 100644
--- a/src/components/views/rooms/wysiwyg_composer/components/WysiwygComposer.tsx
+++ b/src/components/views/rooms/wysiwyg_composer/components/WysiwygComposer.tsx
@@ -25,6 +25,7 @@ import { parsePermalink } from "../../../../../utils/permalinks/Permalinks";
 import { isNotNull } from "../../../../../Typeguards";
 import { useSettingValue } from "../../../../../hooks/useSettings";
 import { useScopedRoomContext } from "../../../../../contexts/ScopedRoomContext.tsx";
+import { useContainsCommand } from "../hooks/useContainsCommand.ts";
 
 interface WysiwygComposerProps {
     disabled?: boolean;
@@ -83,6 +84,9 @@ export const WysiwygComposer = memo(function WysiwygComposer({
         }
     }, [onChange, messageContent, disabled]);
 
+    // Disable formatting buttons if the message content contains a slash command
+    const disableFormatting = useContainsCommand(content, room);
+
     useEffect(() => {
         function handleClick(e: Event): void {
             e.preventDefault();
@@ -124,7 +128,7 @@ export const WysiwygComposer = memo(function WysiwygComposer({
                 handleAtRoomMention={wysiwyg.mentionAtRoom}
                 handleCommand={wysiwyg.command}
             />
-            <FormattingButtons composer={wysiwyg} actionStates={actionStates} />
+            <FormattingButtons composer={wysiwyg} actionStates={actionStates} disabled={disableFormatting} />
             <Editor
                 ref={ref}
                 disabled={!isReady}
diff --git a/src/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand.ts b/src/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand.ts
new file mode 100644
index 0000000000..f6ed1dd778
--- /dev/null
+++ b/src/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand.ts
@@ -0,0 +1,53 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { type Room } from "matrix-js-sdk/src/matrix";
+import { useEffect, useState, useRef } from "react";
+
+import CommandProvider from "../../../../../autocomplete/CommandProvider";
+
+/**
+ * A hook which determines if the given content contains a slash command.
+ * @returns true if the content contains a slash command, false otherwise.
+ * @param content The content to check for commands.
+ * @param room The current room.
+ */
+export function useContainsCommand(content: string | null, room: Room | undefined): boolean {
+    const [contentContainsCommands, setContentContainsCommands] = useState(false);
+    const providerRef = useRef<CommandProvider | null>(null);
+    const currentRoomIdRef = useRef<string | null>(null);
+
+    useEffect(() => {
+        if (!room || !content) {
+            setContentContainsCommands(false);
+            return;
+        }
+
+        // Create or reuse CommandProvider for the current room
+        if (!providerRef.current || currentRoomIdRef.current !== room.roomId) {
+            providerRef.current = new CommandProvider(room);
+            currentRoomIdRef.current = room.roomId;
+        }
+
+        const provider = providerRef.current;
+        provider
+            .getCompletions(content, { start: 0, end: 0 })
+            .then((results) => {
+                if (results.length > 0) {
+                    setContentContainsCommands(true);
+                } else {
+                    setContentContainsCommands(false);
+                }
+            })
+            .catch(() => {
+                // If there's an error getting completions, assume no commands
+                setContentContainsCommands(false);
+            });
+    }, [content, room]);
+
+    return contentContainsCommands;
+}
diff --git a/test/unit-tests/components/views/rooms/wysiwyg_composer/components/FormattingButtons-test.tsx b/test/unit-tests/components/views/rooms/wysiwyg_composer/components/FormattingButtons-test.tsx
index 94d207eb91..5412f96892 100644
--- a/test/unit-tests/components/views/rooms/wysiwyg_composer/components/FormattingButtons-test.tsx
+++ b/test/unit-tests/components/views/rooms/wysiwyg_composer/components/FormattingButtons-test.tsx
@@ -194,4 +194,14 @@ describe("FormattingButtons", () => {
         expect(screen.getByLabelText("Indent increase")).toBeInTheDocument();
         expect(screen.getByLabelText("Indent decrease")).toBeInTheDocument();
     });
+
+    it("Every button should when disabled the component is disabled", () => {
+        renderComponent({ disabled: true });
+
+        Object.values(testCases).forEach((testCase) => {
+            const { label } = testCase;
+            expect(screen.getByLabelText(label)).toHaveClass(classes.disabled);
+            expect(screen.getByLabelText(label)).toBeDisabled();
+        });
+    });
 });
diff --git a/test/unit-tests/components/views/rooms/wysiwyg_composer/components/WysiwygComposer-test.tsx b/test/unit-tests/components/views/rooms/wysiwyg_composer/components/WysiwygComposer-test.tsx
index 2d670dbc6b..610003b8ff 100644
--- a/test/unit-tests/components/views/rooms/wysiwyg_composer/components/WysiwygComposer-test.tsx
+++ b/test/unit-tests/components/views/rooms/wysiwyg_composer/components/WysiwygComposer-test.tsx
@@ -151,6 +151,25 @@ describe("WysiwygComposer", () => {
             // Then it sends a message
             await waitFor(() => expect(onSend).toHaveBeenCalledTimes(0));
         });
+
+        it("Should disable formatting buttons when a slash command is entered", async () => {
+            // When
+            fireEvent.input(screen.getByRole("textbox"), {
+                data: "/rainbow",
+                inputType: "insertText",
+            });
+
+            // Then - wait for all buttons to be rendered and have the disabled class
+            await waitFor(() => {
+                const container = screen.getByTestId("WysiwygComposer");
+                const formattingButtons = container.querySelectorAll(".mx_FormattingButtons_Button");
+                expect(formattingButtons.length).toBeGreaterThan(0);
+
+                formattingButtons.forEach((btn) => {
+                    expect(btn).toHaveClass("mx_FormattingButtons_disabled");
+                });
+            });
+        });
     });
 
     describe("Mentions and commands", () => {
diff --git a/test/unit-tests/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand-test.tsx b/test/unit-tests/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand-test.tsx
new file mode 100644
index 0000000000..084c2b487f
--- /dev/null
+++ b/test/unit-tests/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand-test.tsx
@@ -0,0 +1,161 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { renderHook, waitFor } from "jest-matrix-react";
+import { Room } from "matrix-js-sdk/src/matrix";
+
+import { useContainsCommand } from "../../../../../../../src/components/views/rooms/wysiwyg_composer/hooks/useContainsCommand";
+import { stubClient } from "../../../../../../test-utils";
+
+// Mock CommandProvider
+const mockGetCompletions = jest.fn();
+jest.mock("../../../../../../../src/autocomplete/CommandProvider", () => {
+    return jest.fn().mockImplementation(() => ({
+        getCompletions: mockGetCompletions,
+    }));
+});
+
+describe("useContainsCommand", () => {
+    let room: Room;
+
+    beforeEach(() => {
+        const client = stubClient();
+        room = new Room("!room:example.com", client, "@user:example.com");
+        mockGetCompletions.mockClear();
+        // Default mock to return empty promise
+        mockGetCompletions.mockResolvedValue([]);
+    });
+
+    afterEach(() => {
+        jest.clearAllMocks();
+    });
+
+    it("should return false when content is null", async () => {
+        mockGetCompletions.mockResolvedValue([]);
+
+        const { result } = renderHook(() => useContainsCommand(null, room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+        expect(mockGetCompletions).not.toHaveBeenCalled();
+    });
+
+    it("should return false when content is empty string", async () => {
+        mockGetCompletions.mockResolvedValue([]);
+
+        const { result } = renderHook(() => useContainsCommand("", room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+        expect(mockGetCompletions).not.toHaveBeenCalled();
+    });
+
+    it("should return true when content contains a valid command", async () => {
+        mockGetCompletions.mockResolvedValue([{ type: "command", completion: "/spoiler" }]);
+
+        const { result } = renderHook(() => useContainsCommand("/spoiler test message", room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(true);
+        });
+        expect(mockGetCompletions).toHaveBeenCalledWith("/spoiler test message", { start: 0, end: 0 });
+    });
+
+    it("should return false when content contains no valid commands", async () => {
+        mockGetCompletions.mockResolvedValue([]);
+
+        const { result } = renderHook(() => useContainsCommand("/invalidcommand", room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+        expect(mockGetCompletions).toHaveBeenCalledWith("/invalidcommand", { start: 0, end: 0 });
+    });
+
+    it("should return true for partial command matches", async () => {
+        mockGetCompletions.mockResolvedValue([
+            { type: "command", completion: "/spoiler" },
+            { type: "command", completion: "/shrug" },
+        ]);
+
+        const { result } = renderHook(() => useContainsCommand("/sp", room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(true);
+        });
+        expect(mockGetCompletions).toHaveBeenCalledWith("/sp", { start: 0, end: 0 });
+    });
+
+    it("should update when content changes", async () => {
+        mockGetCompletions.mockResolvedValue([]);
+
+        const { result, rerender } = renderHook(({ content, room }) => useContainsCommand(content, room), {
+            initialProps: { content: "/invalid", room },
+        });
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+
+        // Change to valid command
+        mockGetCompletions.mockResolvedValue([{ type: "command", completion: "/spoiler" }]);
+
+        rerender({ content: "/spoiler", room });
+
+        await waitFor(() => {
+            expect(result.current).toBe(true);
+        });
+        expect(mockGetCompletions).toHaveBeenCalledWith("/spoiler", { start: 0, end: 0 });
+    });
+
+    it("should handle CommandProvider errors gracefully", async () => {
+        mockGetCompletions.mockRejectedValueOnce(new Error("Provider error"));
+
+        const { result } = renderHook(() => useContainsCommand("/test", room));
+
+        // Should remain false even if promise rejects
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+    });
+
+    it("should return false for non-command content", async () => {
+        mockGetCompletions.mockResolvedValue([]); // CommandProvider returns empty for non-commands
+
+        const { result } = renderHook(() => useContainsCommand("regular message", room));
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+        expect(mockGetCompletions).toHaveBeenCalledWith("regular message", { start: 0, end: 0 });
+    });
+
+    it("should reset to false when switching to null content", async () => {
+        mockGetCompletions.mockResolvedValue([{ type: "command", completion: "/spoiler" }]);
+
+        const { result, rerender } = renderHook(
+            ({ content, room }: { content: string | null; room: Room | undefined }) =>
+                useContainsCommand(content, room),
+            {
+                initialProps: { content: "/spoiler" as string | null, room: room as Room | undefined },
+            },
+        );
+
+        await waitFor(() => {
+            expect(result.current).toBe(true);
+        });
+
+        // Switch to null content
+        rerender({ content: null, room });
+
+        await waitFor(() => {
+            expect(result.current).toBe(false);
+        });
+    });
+});