re-arrange to split the async task into two and only wait on the user-blocking one

src/SlashCommands.js

@@ -907,14 +907,14 @@ const aliases = {
 
 
 /**
- * Process the given text for /commands and perform them.
+ * Process the given text for /commands and return a bound method to perform them.
  * @param {string} roomId The room in which the command was performed.
  * @param {string} input The raw text input by the user.
- * @return {Object|null} An object with the property 'error' if there was an error
+ * @return {null|function(): Object} Function returning an object with the property 'error' if there was an error
  * processing the command, or 'promise' if a request was sent out.
  * Returns null if the input didn't match a command.
  */
-export function processCommandInput(roomId, input) {
+export function getCommand(roomId, input) {
     // trim any trailing whitespace, as it can confuse the parser for
     // IRC-style commands
     input = input.replace(/\s+$/, '');
@@ -934,8 +934,6 @@ export function processCommandInput(roomId, input) {
         cmd = aliases[cmd];
     }
     if (CommandMap[cmd]) {
-        return CommandMap[cmd].run(roomId, args);
+        return () => CommandMap[cmd].run(roomId, args);
     }
-    return null;
-    // return reject(_t('Unrecognised command:') + ' ' + input);
 }

src/components/views/rooms/SendMessageComposer.js

@@ -35,7 +35,7 @@ import ReplyThread from "../elements/ReplyThread";
 import {parseEvent} from '../../../editor/deserialize';
 import {findEditableEvent} from '../../../utils/EventUtils';
 import SendHistoryManager from "../../../SendHistoryManager";
-import {processCommandInput} from '../../../SlashCommands';
+import {getCommand} from '../../../SlashCommands';
 import * as sdk from '../../../index';
 import Modal from '../../../Modal';
 import {_t, _td} from '../../../languageHandler';
@@ -197,12 +197,7 @@ export default class SendMessageComposer extends React.Component {
         return false;
     }
 
-    /**
+    _getSlashCommand() {
-     * Parses and executes current input as a Slash Command
-     * @returns {Promise<Symbol|void>} UNKNOWN_CMD if the command is not known,
-     *  SEND_ANYWAY if the input should be sent as message instead
-     */
-    async _tryRunSlashCommand() {
         const commandText = this.model.parts.reduce((text, part) => {
             // use mxid to textify user pills in a command
             if (part.type === "user-pill") {
@@ -210,9 +205,11 @@ export default class SendMessageComposer extends React.Component {
             }
             return text + part.text;
         }, "");
-        const cmd = processCommandInput(this.props.room.roomId, commandText);
+        return [getCommand(this.props.room.roomId, commandText), commandText];
+    }
 
-        if (cmd) {
+    async _runSlashCommand(fn) {
+        const cmd = fn();
         let error = cmd.error;
         if (cmd.promise) {
             try {
@@ -244,18 +241,6 @@ export default class SendMessageComposer extends React.Component {
         } else {
             console.log("Command success.");
         }
-        } else {
-            const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
-            // unknown command, ask the user if they meant to send it as a message
-            const {finished} = Modal.createTrackedDialog("Unknown command", "", QuestionDialog, {
-                title: _t("Unknown Command"),
-                description: _t("Unrecognised command: ") + commandText,
-                button: _t('Send as message'),
-                danger: true,
-            });
-            const [sendAnyway] = await finished;
-            return sendAnyway ? SEND_ANYWAY : UNKNOWN_CMD;
-        }
     }
 
     async _sendMessage() {
@@ -266,13 +251,24 @@ export default class SendMessageComposer extends React.Component {
         let shouldSend = true;
 
         if (!containsEmote(this.model) && this._isSlashCommand()) {
-            const resp = await this._tryRunSlashCommand();
+            const [cmd, commandText] = this._getSlashCommand();
-            if (resp === UNKNOWN_CMD) {
+            if (cmd) {
-                // unknown command, bail to let the user modify it
+                shouldSend = false;
-                return;
+                this._runSlashCommand(cmd);
+            } else {
+                // ask the user if their unknown command should be sent as a message instead
+                const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
+                // unknown command, ask the user if they meant to send it as a message
+                const {finished} = Modal.createTrackedDialog("Unknown command", "", QuestionDialog, {
+                    title: _t("Unknown Command"),
+                    description: _t("Unrecognised command: ") + commandText,
+                    button: _t('Send as message'),
+                    danger: true,
+                });
+                const [sendAnyway] = await finished;
+                // if !sendAnyway bail to let the user edit the composer and try again
+                if (!sendAnyway) return;
             }
-
-            shouldSend = resp === SEND_ANYWAY;
         }
 
         if (shouldSend) {