Consider "end" even in addition to "close" on @serialport/stream

[reconbot]

💥 Proposal

From #1688 (comment) it might be worth adding the end event to the stream. We would do it to work well with other streams.

@HipsterBrown do you think it's needed?

[HipsterBrown]

If we're keeping the Stream interface as an implementation of the Duplex stream, then end could probably be emitted once zero bytes are read -> https://github.com/node-serialport/node-serialport/blob/master/packages/stream/stream.js#L380

Helps keep things consistent with how people learn streams, i.e. https://medium.freecodecamp.org/node-js-streams-everything-you-need-to-know-c9141306be93#a9a7

[reconbot]

The bindings literally never return 0 bytes, it's the spec that they have to return at least a single byte or wait for data. The only time the stream ends is on close.

[reconbot]

And once a stream has ended I'm pretty sure it can't be started again.

[HipsterBrown]

So is the check for 0 bytes in the stream source code just for safe measure?

this.binding.read(pool, start, toRead).then(
    bytesRead => {
      debug('binding.read', `finished`)
      // zero bytes means read means we've hit EOF? Maybe this should be an error
      if (bytesRead === 0) {
        debug('binding.read', 'Zero bytes read closing readable stream')
        this.push(null)
        return
      }
      pool.used += bytesRead
      this.push(pool.slice(start, start + bytesRead))
    },
    err => {
      debug('binding.read', `error`, err)
      if (!err.canceled) {
        this._disconnected(err)
      }
      this._read(bytesToRead) // prime to read more once we're reconnected
    }
  )

[reconbot]

I guess so, I don't really remember =)

[reconbot]

Worked in #1926 thinking it will be an option to enable or disable this behavior. If we have it on by default we need a HUGE warning in the changelog.

[rotu]

It seems unexpected to have this off by default. It means that, while SerialPortStream seems to implement stream.Readable, it does not obey the expected behavior.

Similarly, the finish event does not appear to be implemented.