TypeError: Cannot read property 'unref' of undefined

[lacker]

I'm getting an error from within the bittorrent-protocol module when running a simple WebTorrent download.

/home/lacker/js/node_modules/bittorrent-protocol/index.js:617
    if (this._timeoutUnref && this._timeout.unref) this._timeout.unref()
                                            ^

TypeError: Cannot read property 'unref' of undefined
    at Wire._updateTimeout (/home/lacker/js/node_modules/bittorrent-protocol/index.js:617:45)
    at Wire._callback (/home/lacker/js/node_modules/bittorrent-protocol/index.js:602:52)
    at Wire._onPiece (/home/lacker/js/node_modules/bittorrent-protocol/index.js:507:10)
    at Wire._onMessage (/home/lacker/js/node_modules/bittorrent-protocol/index.js:673:21)
    at Wire._write (/home/lacker/js/node_modules/bittorrent-protocol/index.js:591:12)
    at doWrite (/home/lacker/js/node_modules/bittorrent-protocol/node_modules/readable-stream/lib/_stream_writable.js:428:64)
    at writeOrBuffer (/home/lacker/js/node_modules/bittorrent-protocol/node_modules/readable-stream/lib/_stream_writable.js:417:5)
    at Wire.Object.<anonymous>.Writable.write (/home/lacker/js/node_modules/bittorrent-protocol/node_modules/readable-stream/lib/_stream_writable.js:334:11)
    at Socket.ondata (_stream_readable.js:639:20)
    at emitOne (events.js:116:13)
    at Socket.emit (events.js:211:7)
    at addChunk (_stream_readable.js:263:12)
    at readableAddChunk (_stream_readable.js:250:11)
    at Socket.Readable.push (_stream_readable.js:208:10)
    at TCP.onread (net.js:607:20)

Looks like this._timeoutUnref is set but this._timeout isn't. I'm just creating a client, calling client.add(magnet) on it, and waiting for the "done" event on the response torrent.

[feross]

@lacker What environment are you running this in? It looks like setTimeout() is returning undefined for you, which should not happen. This is the full code:

    this._timeout = setTimeout(() => this._onTimeout(), this._timeoutMs)
    if (this._timeoutUnref && this._timeout.unref) this._timeout.unref()

[lacker]

Ah, I should have updated this issue. I tracked it down, it's from within a unit test that uses jest, which in turn uses jsdom for its "window" object, during the cleanup phase. The jsdom window setTimeout() returns undefined after the window has been closed, which I believe is incorrect behavior, and I reported this against jsdom here:

jsdom/jsdom#2617

It would be handy just to make webtorrent work within test environments if this code also checked that this._timeout was defined before calling this._timeout.unref(). This does seem to be a bug within jsdom rather than a bug within webtorrent per se, but it seems low-priority for jsdom folks.

[feross]

Thanks for following up, @lacker. We use setTimeout all over the codebase. I'd rather not scatter a hack across the codebase to solve a bug in jsdom. I know this probably isn't what you wanted to hear, but I don't think WebTorrent is the right place to fix this.