node package manager
Stop writing boring code. Discover, share, and reuse within your team. Create a free org »


node-pacific CircleCI Coveralls

Ceci n'est pas une pipe

Pacific provides a simple but powerful streaming abstraction. It consist of two concepts: Sinks and Sources.


Pacific is available via npm:

npm install pacific



Sinks are stream consumers. More concretely, they describe how to reduce a stream, by providing three actions:

  • onStart: () => Promise<State>
  • onData: (s: State, i: Input) => Promise<State>
  • onEnd: (s: State) => Promise<Result>

Those three actions are called in order during the lifecycle of the stream. When a stream starts, onStart is called, returning a promise that results in an initial state. As data flows through the stream, onData is called multiple times with the current state and a bit of input, providing the next state. The next onData won't be called unless the promise from the previous call is fulfilled, providing a way to handle back-pressure. At the point where the stream is exhausted, onEnd will be called once with the last state, finalizing it into the end result.


Sources are the objects that take a sink and run it. Two sources of the same type can be combined into a new source, which provides a simple way to build up sources from lots of different parts, concatenating many data fetches.