o-stream

O-Stream

Provides an intuitive interface for node streams, in typescript.

Install

npm install --save o-stream

Or dev:
npm install --save-dev o-stream

Basic Usage

Simple transform stream:

import ObjectStream, { EnteredArgs } from "o-stream"

let incrementStream = ObjectStream.transform<number, number>({
    onEntered: (args: EnteredArgs<number, number>) => {
        args.output.push(args.object + 1);
    }
});

stream.write(4);

let actual = stream.read(); // 5

Output on stream end:

import ObjectStream, { EnteredArgs, EndedArgs } from "o-stream"

let sum = 0;
let sumStream = ObjectStream.transform<number, number>({
    onEntered: (args: EnteredArgs<number, number>) => {
        sum += args.object;
    },
    onEnded: (args: EndedArgs<number>) => {
        args.output.push(sum);
    }
});

sumStream.write(100);
sumStream.write(5);
sumStream.write(-10);
sumStream.end();

let actualSum = sumStream.read(); // 95

Async:

import ObjectStream, { EnteredAsyncArgs, EndedAsyncArgs } from "o-stream"

let sum = 0;
let sumStream = ObjectStream.transform<number, number>({
    onEnteredAsync: (args: EnteredAsyncArgs<number, number>) => {
        sum += args.object;
        args.done();
    },
    onEndedAsync: (args: EndedAsyncArgs<number>) => {
        args.output.push(sum);
        args.done();
    }
});

let num1 = 4;
let num2 = 6;
let num3 = -1;
let expected = num1 + num2 + num3;

sumStream.write(num1);
sumStream.write(num2);
sumStream.write(num3);
sumStream.end();

let actual = sumStream.read();

expect(actual).toBe(expected);

Create a stream from an array:

import ObjectStream from "o-stream"

let stream = ObjectStream.fromArray([1, 2, 3, 5, 8, 13]);