feat: prevent recording of audio from bot users

tests/recorder.test.ts

@@ -1,5 +1,5 @@
 import { EventEmitter } from "node:events";
-import { describe, expect, it, vi } from "vitest";
+import { beforeEach, describe, expect, it, vi } from "vitest";
 
 const speaking = new EventEmitter();
 const subscribe = vi.fn();
@@ -13,6 +13,21 @@ const joinVoiceChannel = vi.fn(() => ({
   destroy: vi.fn(),
 }));
 
+function createChannel() {
+  return {
+    id: "voice-channel",
+    name: "Voice",
+    guild: {
+      id: "guild",
+      voiceAdapterCreator: {},
+      members: {
+        cache: new Map(),
+        fetch: vi.fn(async () => null),
+      },
+    },
+  };
+}
+
 vi.mock("@discordjs/voice", async () => {
   const actual =
     await vi.importActual<typeof import("@discordjs/voice")>(
@@ -26,19 +41,17 @@ vi.mock("@discordjs/voice", async () => {
 });
 
 describe("startRecording", () => {
+  beforeEach(() => {
+    subscribe.mockClear();
+    speaking.removeAllListeners();
+  });
+
   it("does not subscribe to the bot user's own audio", async () => {
     const { startRecording } = await import("../src/recorder");
     const client = {
       user: { id: "bot-user" },
     };
-    const channel = {
-      id: "voice-channel",
-      name: "Voice",
-      guild: {
-        id: "guild",
-        voiceAdapterCreator: {},
-      },
-    };
+    const channel = createChannel();
 
     await startRecording(client as never, channel as never);
     speaking.emit("start", "bot-user");
@@ -46,4 +59,32 @@ describe("startRecording", () => {
 
     expect(subscribe).not.toHaveBeenCalled();
   });
+
+  it("does not subscribe to other bot users", async () => {
+    const { startRecording } = await import("../src/recorder");
+    const client = {
+      user: { id: "self-user" },
+      users: {
+        cache: new Map([
+          [
+            "music-bot",
+            {
+              id: "music-bot",
+              username: "Jockie Music",
+              tag: "Jockie Music#8158",
+              bot: true,
+              displayAvatarURL: vi.fn(() => "https://example.com/avatar.png"),
+            },
+          ],
+        ]),
+        fetch: vi.fn(async () => null),
+      },
+    };
+
+    await startRecording(client as never, createChannel() as never);
+    speaking.emit("start", "music-bot");
+    await new Promise((resolve) => setImmediate(resolve));
+
+    expect(subscribe).not.toHaveBeenCalled();
+  });
 });