fix: destroy the discord client when login fails

src/discord-rpc.js

@@ -25,7 +25,13 @@ export function createDiscordRpcTransport({ clientId, createClient } = {}) {
     if (!next || typeof next.login !== "function" || typeof next.setActivity !== "function" || typeof next.clearActivity !== "function") {
       throw new TypeError("RPC client: expected login, setActivity and clearActivity functions");
     }
-    await next.login({ clientId });
+    try { await next.login({ clientId }); }
+    catch (error) {
+      // A failed client was never adopted, so close() cannot release it.
+      // Cleanup must not delay or replace the original login failure.
+      try { Promise.resolve(next.destroy?.()).catch(() => {}); } catch {}
+      throw error;
+    }
     // A close during createClient/login must not be undone by this late
     // arrival: destroy the new client instead of adopting it.
     if (epoch !== generation) {

test/discord-rpc-login-cleanup.test.js

@@ -0,0 +1,22 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {createDiscordRpcTransport} from '../src/discord-rpc.js';
+for(const mode of ['sync','async','throwing','rejecting','pending']){
+ test(`failed RPC login destroys discarded client (${mode}) and preserves error`,async()=>{
+  let destroyed=0,created=0,timer;
+  const error=new Error('fixture login failed');
+  const factory=()=>({login:async()=>{throw error;},setActivity:async()=>{},clearActivity:async()=>{},destroy:()=>{destroyed++;if(mode==='async')return Promise.resolve();if(mode==='throwing')throw new Error('cleanup');if(mode==='rejecting')return Promise.reject(new Error('cleanup'));if(mode==='pending')return new Promise(()=>{});}});
+  const transport=createDiscordRpcTransport({clientId:'123456789012345678',createClient:async()=>{created++;return factory();}});
+  try{
+   for(let i=1;i<=2;i++){
+    await assert.rejects(Promise.race([transport.connect(),new Promise((_,reject)=>{timer=setTimeout(()=>reject(new Error('cleanup blocked')),100);})]),e=>e===error);
+    clearTimeout(timer);assert.equal(destroyed,i);assert.equal(created,i);assert.equal(transport.connected,false);
+   }
+   await transport.close();assert.equal(destroyed,2);
+  }finally{clearTimeout(timer);}
+ });
+}
+test('failed RPC login without destroy preserves error',async()=>{
+ const error=new Error('fixture');const transport=createDiscordRpcTransport({clientId:'123456789012345678',createClient:async()=>({login:async()=>{throw error;},setActivity:async()=>{},clearActivity:async()=>{}})});
+ await assert.rejects(transport.connect(),e=>e===error);
+});