I am using a library which uses RxJS and I am brand new to RxJS so, although I have googled and tried to do my own research I am still a bit lost.

This library has a function that returns an observable. That observable really only returns a single message when subscribed but I need to wait for the data contained within that message before my code can continue.

I have read about chaining observables and all of that but what I am really after is a very simple async/await pattern. I notice there is a .toPromise() on the observable which you can await on, which is fine, however it appears that promise is resolved before the full execution of my next() function which results in a timing issue with the variables it was setting.

Does that sound correct? How can I simply await an observable AND all its side effects such as calls to next()?

What I have ended up doing, which works reliably but seems overkill is to wrap in a promise as demonstrated below. Is there a more succinct way?

   const result = await new Promise((resolve, reject) => {

      const s = jupyter.sessions.create(this._serverConfig,
        {
          kernel: {name: this._kernelName},
          name: this._sessionName,
          path: '/path',
          type: 'notebook'
      });
  
      s.pipe(take(1)).subscribe({
        next(x) {
            resolve({sessionId: x.response.id, kernelId: x.response.kernel.id});
        },
        error(err) {
          reject(err);
        },
      });
    });

    this._sessionId = result.sessionId;
    this._kernelId = result.kernelId;

For completeness, this is the old code that is NOT working. In this code the await completes in a race condition with the next function. That is, randomly both sessionId and kernelId are undefined as per the log message that follows the await

  s.subscribe({
      next(x) {
          console.log(x);
          sessionId = x.response.id;
          kernelId = x.response.kernel.id;
      },
      error(err) {
        console.error('Got an error from kernel creation:')
        console.error(err);
      },
    })
    .add(() => {
      console.log('Connection subscription exiting');
    });

    await s.toPromise();
    console.log(`Found session id ${sessionId} and kernel id ${kernelId}`);