Fix emoticon slash commands including stale buffers (#32928)

apps/web/src/slash-commands/emoticon.ts

@@ -11,14 +11,15 @@ import { Command } from "./command";
 import { successSync } from "./utils";
 import { CommandCategories } from "./interface";
 
-export function emoticon(command: string, description: TranslationKey, message: string): Command {
+export function emoticon(command: string, description: TranslationKey, prefix: string): Command {
     return new Command({
         command,
         args: "<message>",
         description,
         runFn: function (_cli, _roomId, _threadId, args) {
+            let message = prefix;
             if (args) {
-                message = message + " " + args;
+                message += " " + args;
             }
             return successSync(ContentHelpers.makeTextMessage(message));
         },

apps/web/test/unit-tests/slash-commands/emoticons-test.ts

@@ -20,6 +20,11 @@ describe.each(["shrug", "tableflip", "unflip", "lenny"])("/%s", (commandName: st
     it("should match snapshot with args", async () => {
         const { client, command } = setUpCommandTest(roomId, `/${commandName}`);
 
-        await expect(command.run(client, roomId, null, "this is a test message").promise).resolves.toMatchSnapshot();
+        const initialResult = await command.run(client, roomId, null, "this is a test message").promise;
+        expect(initialResult).toMatchSnapshot();
+        // We run this twice to ensure it doesn't stack the buffer
+        await expect(command.run(client, roomId, null, "this is a test message").promise).resolves.toEqual(
+            initialResult,
+        );
     });
 });