Not signalling `end` event? about through2 HOT 5 CLOSED

Try 'finish' instead. Also you could try the second callback to the constructor which is like a cleanup at the end.

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Thanks! works!

from through2.

I have a similar problem but neither end nor finish works for me:

  myMongoDbCollection.aggregate([
    ... aggregation pipeline
  ])
    .pipe(through2.obj(function (obj, _, cb) {
      this.push(turnObjIntoString(obj))
      cb()
    }))
    .pipe(process.stdout)
    .on('finish', closeDB)
    .on('error', closeDB)

The result is printed to stdout as expected but the closeDB function is never called and the program never exists.
If I add the listeners before I pipe, then they are called and the program is closed but the print becomes messed up.

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@TheLudd you're listening to events on process.stdout, I can't say off the top of my head but it could be that it's not going "close" for you.

  myMongoDbCollection.aggregate([
    ... aggregation pipeline
  ])
    .pipe(through2.obj(function (obj, _, cb) {
      this.push(turnObjIntoString(obj))
      cb()
    }))
    .on('finish', closeDB)
    .on('error', closeDB)
    .pipe(process.stdout)

.. maybe? also, error isn't propagated between pipe() so it's not good enough to just stick it at the end of a chain, you should listen for it on each stream in the chain that could trigger an error.

Also check out:

• https://nodejs.org/api/stream.html#stream_stream_pipeline_streams_callback
• https://nodejs.org/api/stream.html#stream_stream_finished_stream_options_callback

They might be helpful for various situations.

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@rvagg Thanks, rearranging the last lines like this did the trick:

    .on('finish', closeDB)
    .on('error', closeDB)
    .pipe(process.stdout)

Will have to read up a bit on piping and errors....

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