Laravel-like pipelines in JavaScript and TypeScript

pipeline.js

export function pipeline(initialValue, pipes, then) {
  then = then ?? ((t) => t);
  const pipelineCallback = pipes
    .slice()
    .reverse()
    .reduce((next, pipe) => (passable) => pipe(passable, next), then);

  return pipelineCallback(initialValue);
}

export async function asyncPipeline(initialValue, pipes, then) {
  then = then ?? (async (t) => t);
  const pipelineCallback = pipes
    .slice()
    .reverse()
    .reduce((next, pipe) => (async (passable) => pipe(await passable, next)), then);

  return pipelineCallback(initialValue);
}

const pipeA = (x, next) => next(x + 1);
const pipeB = (x, next) => next(x * 2);
const result = pipeline(10, [pipeA, pipeB]);
console.log(result);

const asyncPipeA = async (x, next) => next(x + 1);
const asyncPipeB = async (x, next) => next(x * 2);
const asyncResult = asyncPipeline(10, [asyncPipeA, asyncPipeB]);
asyncResult.then((x) => { console.log(x); });

pipeline.ts

type Identity<T> = (t: T) => T
export type Pipe<T> = (t: T, next: Identity<T>) => T;
export function pipeline<T>(initialValue: T, pipes: Pipe<T>[], then: Identity<T> | null = null): T {
  then = then ?? ((t) => t);
  const pipelineCallback = pipes
    .slice()
    .reverse()
    .reduce<Identity<T>>((next, pipe) => (passable: T) => pipe(passable, next), then);

  return pipelineCallback(initialValue);
}

type AsyncIdentity<T> = (t: T) => Promise<T>
export type AsyncPipe<T> = (t: T, next: AsyncIdentity<T>) => Promise<T>;
export async function asyncPipeline<T>(initialValue: T, pipes: AsyncPipe<T>[], then: AsyncIdentity<T> | null = null): Promise<T> {
  then = then ?? (async (t) => t);
  const pipelineCallback = pipes
    .slice()
    .reverse()
    .reduce<AsyncIdentity<T>>((next, pipe) => (async (passable: T) => pipe(await passable, next)), then);

  return pipelineCallback(initialValue);
}

const pipeA: Pipe<number> = (x, next) => next(x + 1);
const pipeB: Pipe<number> = (x, next) => next(x * 2);
const result = pipeline<number>(10, [pipeA, pipeB]);
console.log(result);

const asyncPipeA: AsyncPipe<number> = async (x, next) => next(x + 1);
const asyncPipeB: AsyncPipe<number> = async (x, next) => next(x * 2);
const asyncResult = asyncPipeline<number>(10, [asyncPipeA, asyncPipeB]);
asyncResult.then((x) => { console.log(x); });

Nice! 👍

Does this actually work? 🤩

@tjventurini Yes 🙂 I've used this pattern in a few small apps and really liked it. Not sure how this scale to larger apps though but no reason it shouldn't work.

@lorisleiva Awesome! Thanks for the feedback 👍 Hmm... need to build something with that now 🤓

@tjventurini Do it! 🚀 😊

Thank you! Have been frustrated not having something like this haha. Was spoiled by Laravel's simple pipeline many years ago and here I am, finding this ! You should create a small package about this that can be scaled by community