How do I stub a function that being promisify'd by bluebird?

[stringbeans]

Hi!

I have a function that does something like this...

function someFunction(sqs, message) {
  const sendMessage = Promise.promisify(sqs.sendMessage.bind(sqs));
  return sendMessage(message)
}

How would I setup a test such that i can verify whether sendMessage is called correctly? I understand I can just pass the "promisified" version of sendMessage into someFunction and that eases the stubbing, but it makes my code a little messy.

As for the signature of sqs.sendMessage it would be (message, callbackFn)

Thanks in advance!

[searls]

Since the promisification is an implementation detail of the function, then the public contract between it and the test is that sqs should be passed something that expects the callback. As a result, I would pass it a test double wired to respond to a callback and verify that it returns a promise that resolves to the expected value:

// assuming you have a done() callback or something
var sqs = td.object(['sendMessage'])
td.when(sqs.sendMessage('lol')).thenCallback(null, 'kek')

var result = someFunction(sqs, 'lol')

result.then(function(result) { 
  assert.equal(result, 'kek')
  done()
})

[stringbeans]

@searls thank you very much!