pulsar

Given an emitter, event name and pulse delay, emit events until you want them to stop

Install

$ npm install @lxghtless/pulsar

Usage

const pulsar = require('@lxghtless/pulsar');

const emitter = new EventEmitter(); // any emitter
const eventName = 'pulse'; // any string
const pulseDelay = 10; // ms

emitter.on(eventName, () => {
    // do stuff every {pulseDelay}
});

const context = pulsar(emitter, eventName, pulseDelay);
// context.emit => true
// context.forever => p-forever promise return
// context.trackedEmitter => emitter

// stop pulsar
context.emit = false;

// wait for complete spin down if needed
await Promise.resolve(context.forever);

Prevents multiple emitters

const test = require('ava');
const pulsar = require('@lxghtless/pulsar');

test('pulsar pulses and stops', async t => {
    const emitter = new EventEmitter();
    const eventName = 'pulse'; // any string
    const pulseDelay = 10; // ms
    const context = pulsar(emitter, eventName, pulseDelay);

    const emitter2 = new EventEmitter();
    const context2 = pulsar(emitter2, eventName, pulseDelay);

    t.false(emitter.emit, 'second emitter was not stopped');
    t.true(context2.emit, 'third emitter has not started');
    t.false(emitter === context2.trackedEmitter);

    context2.emit = false;

    // Wait for spin down
    await Promise.resolve(context.forever);
    await Promise.resolve(context2.forever);
});

API

pulsar(emitter, eventName, pulseDelay)

emitter

Type: object

Any emitter (e.g. require('events').EventEmitter, npm i emittery, etc.).

eventName

Type: string

Name of the event to emit.

pulseDelay

Type: number

Milliseconds to delay between events

License

ISC © 2019, lxghtlxss