Can I break a chain early with bluebird Promises?

Question

I don't necessarily want to error, but I have:

getFromDb().then (tradeData) ->
  if not tradeData
    # DO NOT CONTINUE THE CHAIN
  else
    getLatestPrice tradeData
.then (latestPrice) ->
  ...
.then ->
  ...
.then ->
  ...
.catch (err) ->
  next err

Any way for me to abort the chain if there is no tradeData?

Answer 1

getFromDb().then (tradeData) ->
  if tradeData
    getLatestPrice tradeData ->
      .then (latestPrice) ->
        ...
      .then ->
        ...
      .then ->
        ...
      .catch (err) ->
        next err
  else
    getSomethingElse ->
       send("no data")

In 3.0, you will be able to do this:

p = getFromDb().then (tradeData) ->
  if not tradeData
    send("no data");
    p.break()
  else
    getLatestPrice tradeData
.then (latestPrice) ->
  ...
.then ->
  ...
.then ->
  ...
.catch (err) ->
  next err