s3.getObject().createReadStream() : How to catch the error?

Question

I am trying to write a program to get a zip file from s3, unzip it, then upload it to S3. But I found two exceptions that I can not catch.

1.

Answer 1

You can listen to events (like error, data, finish) in the stream you are receiving back. Read more on events

function getObjectStream (filePath) {
  return s3.getObject({
    Bucket: bucket,
    Key: filePath
  }).createReadStream()
}

let readStream = getObjectStream('/path/to/file.zip')
readStream.on('error', function (error) {
  // Handle your error here.
})

Tested for "No Key" error.

it('should not be able to get stream of unavailable object', function (done) {
  let filePath = 'file_not_available.zip'

  let readStream = s3.getObjectStream(filePath)
  readStream.on('error', function (error) {
    expect(error instanceof Error).to.equal(true)
    expect(error.message).to.equal('The specified key does not exist.')
    done()
  })
})

Tested for success.

it('should be able to get stream of available object', function (done) {
  let filePath = 'test.zip'
  let receivedBytes = 0

  let readStream = s3.getObjectStream(filePath)
  readStream.on('error', function (error) {
    expect(error).to.equal(undefined)
  })
  readStream.on('data', function (data) {
    receivedBytes += data.length
  })
  readStream.on('finish', function () {
    expect(receivedBytes).to.equal(3774)
    done()
  })
})