Why uses TopologyLocal Callbacks and not Promises in his API?

[S0c5]

Hello guys! Awesome project but looking inside your code I saw callback implementations, I wanted to know what Is the reason behind.

[bergloman]

Hi. The reason is simply due to age - when the project was in incubation phase, the promises mechanism was not standardized, many libraries had no support for them, our target environment was conservative regarding the node version etc. Hence we couldn't use promises back then. A prototype of promise-based implementation was started but many breaking changes would need to be handled, so the development didn't proceed.

However, we do support async bolt and spout wrappers to handle promise-based implementations, see IBoltAsync and ISpoutAsync.