我还没有看到这些结构被大量使用，但我发现自己编写它们是为了在通常不会返回Promise的函数中使用 async/await，例如

chan.consume(queue, (msg) => {
  this.pendingMsgs++; // executed immediately
  (async () => {
    await this.handleMessage(msg);
    this.pendingMsgs--;
    if (cancelled && this.pendingMsgs === 0) {
       await chan.close();
       await this.amqpConnectionPool.release(conn);
    } 
  })();
});

与

chan.consume(queue, async (msg) => { // external lib does not expect a return value from this callback
  this.pendingMsgs++;  // executed in promise context(?)
  await this.handleMessage(msg);
  this.pendingMsgs--;
    if (cancelled && this.pendingMsgs === 0) {
       await chan.close();
       await this.amqpConnectionPool.release(conn);
    }
});

或者

chan.consume(queue, (msg) => {
  this.pendingMsgs++;  // no await - excess function decls & nesting
  this.handleMessage(msg).then(() => {
    this.pendingMsgs--;
    if (cancelled && this.pendingMsgs === 0) {
       chan.close().then(() => {
         this.amqpConnectionPool.release(conn);
       });
    }
  });
});

这是“一件事”吗？这里有我应该注意的陷阱吗？在这种情况下使用 async/await 的缺点是什么？