Handle command completions in RTE (#10521)

* pass handleCommand prop down and use it in WysiwygAutocomplete

* allow a command to generate a query from buildQuery

* port command functionality into the sendMessage util

* tidy up comments

* remove use of shouldSend and update comments

* remove console log

* make logic more explicit and amend comment

* uncomment replyToEvent block

* update util test

* remove commented out test

* use local text over import from current composer

* expand tests

* expand tests

* handle the FocusAComposer action for the wysiwyg composer

* remove TODO comment

* remove TODO

* test for action dispatch

* fix failing tests

* tidy up tests

* fix TS error and improve typing

* fix TS error

* amend return types for sendMessage, editMessage

* fix null content TS error

* fix another null content TS error

* use as to correct final TS error

* remove undefined argument

* try to fix TS errors for editMessage function usage

* tidy up

* add TODO

* improve comments

* update comment

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

@@ -28,7 +28,7 @@ export const dynamicImportSendMessage = async (
     message: string,
     isHTML: boolean,
     params: SendMessageParams,
-): Promise<ISendEventResponse> => {
+): Promise<ISendEventResponse | undefined> => {
     const { sendMessage } = await import("./utils/message");
 
     return sendMessage(message, isHTML, params);

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

@@ -35,6 +35,12 @@ interface WysiwygAutocompleteProps {
      * a mention in the autocomplete list or pressing enter on a selected item
      */
     handleMention: FormattingFunctions["mention"];
+
+    /**
+     * This handler will be called with the display text for a command on clicking
+     * a command in the autocomplete list or pressing enter on a selected item
+     */
+    handleCommand: FormattingFunctions["command"];
 }
 
 /**
@@ -45,13 +51,23 @@ interface WysiwygAutocompleteProps {
  * @param props.ref - the ref will be attached to the rendered `<Autocomplete />` component
  */
 const WysiwygAutocomplete = forwardRef(
-    ({ suggestion, handleMention }: WysiwygAutocompleteProps, ref: ForwardedRef<Autocomplete>): JSX.Element | null => {
+    (
+        { suggestion, handleMention, handleCommand }: WysiwygAutocompleteProps,
+        ref: ForwardedRef<Autocomplete>,
+    ): JSX.Element | null => {
         const { room } = useRoomContext();
         const client = useMatrixClientContext();
 
         function handleConfirm(completion: ICompletion): void {
             // TODO handle all of the completion types
             // Using this to pick out the ones we can handle during implementation
+            if (completion.type === "command") {
+                // TODO determine if utils in SlashCommands.tsx are required
+
+                // trim the completion as some include trailing spaces, but we always insert a
+                // trailing space in the rust model anyway
+                handleCommand(completion.completion.trim());
+            }
             if (client && room && completion.href && (completion.type === "room" || completion.type === "user")) {
                 handleMention(
                     completion.href,
@@ -61,6 +77,8 @@ const WysiwygAutocomplete = forwardRef(
             }
         }
 
+        // TODO - determine if we show all of the /command suggestions, there are some options in the
+        // list which don't seem to make sense in this context, specifically /html and /plain
         return room ? (
             <div className="mx_WysiwygComposer_AutoCompleteWrapper" data-testid="autocomplete-wrapper">
                 <Autocomplete

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

@@ -91,7 +91,7 @@ export const WysiwygComposer = memo(function WysiwygComposer({
             }
         }
 
-        const mentions = ref.current?.querySelectorAll("a[data-mention-type]");
+        const mentions: NodeList | undefined = ref.current?.querySelectorAll("a[data-mention-type]");
         if (mentions) {
             mentions.forEach((mention) => mention.addEventListener("click", handleClick));
         }
@@ -108,7 +108,12 @@ export const WysiwygComposer = memo(function WysiwygComposer({
             onFocus={onFocus}
             onBlur={onFocus}
         >
-            <WysiwygAutocomplete ref={autocompleteRef} suggestion={suggestion} handleMention={wysiwyg.mention} />
+            <WysiwygAutocomplete
+                ref={autocompleteRef}
+                suggestion={suggestion}
+                handleMention={wysiwyg.mention}
+                handleCommand={wysiwyg.command}
+            />
             <FormattingButtons composer={wysiwyg} actionStates={actionStates} />
             <Editor
                 ref={ref}

src/components/views/rooms/wysiwyg_composer/hooks/useEditing.ts

@@ -29,7 +29,7 @@ export function useEditing(
 ): {
     isSaveDisabled: boolean;
     onChange(content: string): void;
-    editMessage(): Promise<ISendEventResponse>;
+    editMessage(): Promise<ISendEventResponse | undefined>;
     endEditing(): void;
 } {
     const roomContext = useRoomContext();
@@ -45,11 +45,12 @@ export function useEditing(
         [initialContent],
     );
 
-    const editMessageMemoized = useCallback(
-        () =>
-            !!mxClient && content !== undefined && editMessage(content, { roomContext, mxClient, editorStateTransfer }),
-        [content, roomContext, mxClient, editorStateTransfer],
-    );
+    const editMessageMemoized = useCallback(async () => {
+        if (mxClient === undefined || content === undefined) {
+            return;
+        }
+        return editMessage(content, { roomContext, mxClient, editorStateTransfer });
+    }, [content, roomContext, mxClient, editorStateTransfer]);
 
     const endEditingMemoized = useCallback(() => endEditing(roomContext), [roomContext]);
     return { onChange, editMessage: editMessageMemoized, endEditing: endEditingMemoized, isSaveDisabled };

src/components/views/rooms/wysiwyg_composer/hooks/useWysiwygSendActionHandler.ts

@@ -46,6 +46,7 @@ export function useWysiwygSendActionHandler(
 
             switch (payload.action) {
                 case "reply_to_event":
+                case Action.FocusAComposer:
                 case Action.FocusSendMessageComposer:
                     focusComposer(composerElement, context, roomContext, timeoutId);
                     break;

src/components/views/rooms/wysiwyg_composer/utils/autocomplete.ts

@@ -29,9 +29,8 @@ import * as Avatar from "../../../../../Avatar";
  * with @ for a user query, # for a room or space query
  */
 export function buildQuery(suggestion: MappedSuggestion | null): string {
-    if (!suggestion || !suggestion.keyChar || suggestion.type === "command") {
+    if (!suggestion || !suggestion.keyChar) {
         // if we have an empty key character, we do not build a query
-        // TODO implement the command functionality
         return "";
     }
 

src/components/views/rooms/wysiwyg_composer/utils/message.ts

@@ -15,7 +15,7 @@ limitations under the License.
 */
 
 import { Composer as ComposerEvent } from "@matrix-org/analytics-events/types/typescript/Composer";
-import { IEventRelation, MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { IContent, IEventRelation, MatrixEvent } from "matrix-js-sdk/src/models/event";
 import { ISendEventResponse, MatrixClient } from "matrix-js-sdk/src/matrix";
 import { THREAD_RELATION_TYPE } from "matrix-js-sdk/src/models/thread";
 
@@ -33,6 +33,11 @@ import { endEditing, cancelPreviousPendingEdit } from "./editing";
 import EditorStateTransfer from "../../../../../utils/EditorStateTransfer";
 import { createMessageContent } from "./createMessageContent";
 import { isContentModified } from "./isContentModified";
+import { CommandCategories, getCommand } from "../../../../../SlashCommands";
+import { runSlashCommand, shouldSendAnyway } from "../../../../../editor/commands";
+import { Action } from "../../../../../dispatcher/actions";
+import { addReplyToMessageContent } from "../../../../../utils/Reply";
+import { attachRelation } from "../../SendMessageComposer";
 
 export interface SendMessageParams {
     mxClient: MatrixClient;
@@ -47,8 +52,8 @@ export async function sendMessage(
     message: string,
     isHTML: boolean,
     { roomContext, mxClient, ...params }: SendMessageParams,
-): Promise<ISendEventResponse> {
-    const { relation, replyToEvent } = params;
+): Promise<ISendEventResponse | undefined> {
+    const { relation, replyToEvent, permalinkCreator } = params;
     const { room } = roomContext;
     const roomId = room?.roomId;
 
@@ -71,9 +76,51 @@ export async function sendMessage(
     }*/
     PosthogAnalytics.instance.trackEvent<ComposerEvent>(posthogEvent);
 
-    const content = await createMessageContent(message, isHTML, params);
+    let content: IContent | null = null;
 
-    // TODO slash comment
+    // Functionality here approximates what can be found in SendMessageComposer.sendMessage()
+    if (message.startsWith("/") && !message.startsWith("//")) {
+        const { cmd, args } = getCommand(message);
+        if (cmd) {
+            // TODO handle /me special case separately, see end of SlashCommands.Commands
+            const threadId = relation?.rel_type === THREAD_RELATION_TYPE.name ? relation?.event_id : null;
+            let commandSuccessful: boolean;
+            [content, commandSuccessful] = await runSlashCommand(cmd, args, roomId, threadId ?? null);
+
+            if (!commandSuccessful) {
+                return; // errored
+            }
+
+            if (
+                content &&
+                (cmd.category === CommandCategories.messages || cmd.category === CommandCategories.effects)
+            ) {
+                attachRelation(content, relation);
+                if (replyToEvent) {
+                    addReplyToMessageContent(content, replyToEvent, {
+                        permalinkCreator,
+                        // Exclude the legacy fallback for custom event types such as those used by /fireworks
+                        includeLegacyFallback: content.msgtype?.startsWith("m.") ?? true,
+                    });
+                }
+            } else {
+                // instead of setting shouldSend to false as in SendMessageComposer, just return
+                return;
+            }
+        } else {
+            const sendAnyway = await shouldSendAnyway(message);
+            // re-focus the composer after QuestionDialog is closed
+            dis.dispatch({
+                action: Action.FocusAComposer,
+                context: roomContext.timelineRenderingType,
+            });
+            // if !sendAnyway bail to let the user edit the composer and try again
+            if (!sendAnyway) return;
+        }
+    }
+
+    // if content is null, we haven't done any slash command processing, so generate some content
+    content ??= await createMessageContent(message, isHTML, params);
 
     // TODO replace emotion end of message ?
 
@@ -92,7 +139,7 @@ export async function sendMessage(
 
     const prom = doMaybeLocalRoomAction(
         roomId,
-        (actualRoomId: string) => mxClient.sendMessage(actualRoomId, threadId, content),
+        (actualRoomId: string) => mxClient.sendMessage(actualRoomId, threadId, content as IContent),
         mxClient,
     );
 
@@ -108,7 +155,7 @@ export async function sendMessage(
 
     dis.dispatch({ action: "message_sent" });
     CHAT_EFFECTS.forEach((effect) => {
-        if (containsEmoji(content, effect.emojis)) {
+        if (content && containsEmoji(content, effect.emojis)) {
             // For initial threads launch, chat effects are disabled
             // see #19731
             const isNotThread = relation?.rel_type !== THREAD_RELATION_TYPE.name;
@@ -146,7 +193,7 @@ interface EditMessageParams {
 export async function editMessage(
     html: string,
     { roomContext, mxClient, editorStateTransfer }: EditMessageParams,
-): Promise<ISendEventResponse> {
+): Promise<ISendEventResponse | undefined> {
     const editedEvent = editorStateTransfer.getEvent();
 
     PosthogAnalytics.instance.trackEvent<ComposerEvent>({