@nodejs/streams

Unfortunately ServerResponse is not a real stream and not entirely consistent. We've tried to fix this, but unfortunately it breaks the ecosystem. Maybe we can do another take on it @mcollina?

streams no longer output errors when destroyed/ended, you need to check before piping to them

Not sure what you mean here? You don't need to check anything if you us pipeline.

'm not sure how to safely check again errored, but I'd assume it would always signal destroyed.

Your assumption should be correct.

Not sure what you mean here? You don't need to check anything if you us pipeline.

Not needed for pipeline. It is needed for .pipe because unwritable streams can't emit 'end' or 'error'. I used to do something like this (simplified), because I was sometimes streaming chunks from a CDN, or piping it.

if (!destination.writable) return false; // Guard against `.pipe` leak
try { 
  if (source instanceof Readable) {
    destination.on('close', ...);
    destination.on('end', ...);
    source.pipe(destination);
  } else {
    destination.write(source);
  }
} catch ( e ) { return false };
return true;

If destination is ServerResponse (http1), source would never be consumed and never be released and garbage collected, causing a leak. Small because I mostly have HTTPS/HTTP2 traffic, but it happens. The try/catch probably isn't needed after v14 since ERR_STREAM_DESTROYED no longer throws on write. Not 100% sure. But, I have to replace the first line, I believe, with this:

  function isWritable(writableLike) {
    return (!writableLike.destroyed && !writableLike.writableEnded);
  }