fetch-plan.md

Clone instead of reading the response.

fetch(input, init)
  .then(res => {
    // Store the response back from the server. This response will be
    // kept in an unused state. Anytime a user requests it, it will be
    // cloned from.
    cache[key] = {
      res,
      // whether or not the data is still being returned from the server or not
      isStreaming: true
    };
    
    // Track the stream status with a clone. This will update
    // the `isStreaming` property once it is done
    trackStream(res.clone(), key);
    
    // Return the cloned response to the user
    return res.clone();
  });

Caveats

• Cannot push an update to the user once the stream is done
• Would probably need a terrible API: myLib.isStreaming(), or something

Or...

fetch(url, {
  observe(observer) { 
    observer.onresponseprogress = e => console.log(e);
    observer.onrequestprogress = e => console.log(e);
    observer.onstatechange = n => console.log(observer.state)
  }
)