readme.md

Laygo

Type-safe pipelines for Typescript.

Building pipelines shouldn't be difficult but existing packages didn't fit the bill.

Rxjs was too heavy for my needs

Highland.js was good, but it doesn't handle async (read stackoverflow and the issue list)

Scramjet doesn't have any type safety built into their setup

ts-functional-pipe is too basic and I don't like the way pipe and compose functions are implemented.

Goal is to take what I think are the best parts of those packages and create something very lightweight that also performs well.

Example

const result = await laygo()
    .from(["Hello", "world"])
    .map(val => val.toUpperCase())
    .filter(val => ["HELLO"].includes(val))
    .split("")
    .chunk(2)
    .result();

Result will be ["WO","RL","D"]

How it works

By itself the example above is not that impressive but from() accepts streams and generators as well.

You can output a generator or await a result, but you can also pipe output into a stream and properly await until no data is coming through anymore.

Moreover, you can compose more complicated pipelines using the through function. It's incredubly useful when you have to reuse the same chunk of code across the codebase, but you care only about changing the core.

const schema = z.object({
    id: z.number(),
    name: z.string()
});

// you can be more strict with types as well
const pipeline = (p: Pipeline<unknown>) => laygo()
    .from(fs.createReadStream("./source.json"))
    .map(JSON.parse)
    .through(p)
    .map(JSON.stringify)
    .append("\n")
    .pipe(fs.createWriteStream("./destination.json"));

const result = await pipeline((laygo) =>
  laygo.map(schema.parse).filter(({ id }) => id < 100)
);