asyncro

What is asyncro?

The asyncro npm package provides utilities for working with asynchronous code in JavaScript, making it easier to manage and control asynchronous operations. It offers a variety of functions to handle promises and async/await patterns more effectively.

What are asyncro's main functionalities?

map

The `map` function allows you to apply an asynchronous function to each item in an array and returns a promise that resolves when all the operations are complete. This is useful for performing parallel asynchronous operations on array elements.

const asyncro = require('asyncro');

async function example() {
  const numbers = [1, 2, 3, 4, 5];
  const results = await asyncro.map(numbers, async (num) => {
    return num * 2;
  });
  console.log(results); // [2, 4, 6, 8, 10]
}
example();

series

The `series` function executes an array of asynchronous functions in series, meaning one after the other. It returns a promise that resolves with an array of results once all functions have completed. This is useful for tasks that need to be performed sequentially.

const asyncro = require('asyncro');

async function example() {
  const tasks = [
    async () => { return 1; },
    async () => { return 2; },
    async () => { return 3; }
  ];
  const results = await asyncro.series(tasks);
  console.log(results); // [1, 2, 3]
}
example();

parallel

The `parallel` function executes an array of asynchronous functions in parallel, meaning all at the same time. It returns a promise that resolves with an array of results once all functions have completed. This is useful for tasks that can be performed concurrently.

const asyncro = require('asyncro');

async function example() {
  const tasks = [
    async () => { return 1; },
    async () => { return 2; },
    async () => { return 3; }
  ];
  const results = await asyncro.parallel(tasks);
  console.log(results); // [1, 2, 3]
}
example();

Other packages similar to asyncro

async

The async package provides a comprehensive set of functions for working with asynchronous JavaScript. It includes utilities for parallel, series, and waterfall execution, among others. Compared to asyncro, async offers a broader range of utilities and is more established in the community.

bluebird

Bluebird is a fully-featured promise library that provides powerful extensions to the native Promise API. It includes utilities for managing asynchronous code, such as `map`, `reduce`, and `each`. Bluebird is known for its performance and extensive feature set, making it a strong alternative to asyncro.

p-map

The p-map package allows you to map over promises concurrently with a specified concurrency limit. It is a lightweight and focused alternative to asyncro's map function, providing fine-grained control over concurrency.

README

asyncro

It's the map(), reduce() & filter() you know, but with support for async callbacks!

Installation

npm install --save asyncro

Example

import { map } from 'asyncro';

async function example() {
	return await map(
		['foo', 'bar'],
		async name => fetch('./'+name)
	)
}

API

reduce

Invoke an async reducer function on each item in the given Array, where the reducer transforms an accumulator value based on each item iterated over. Note: because reduce() is order-sensitive, iteration is sequential.

This is an asynchronous version of Array.prototype.reduce()

Parameters

• array Array The Array to reduce
• reducer Function Async function, gets passed (accumulator, value, index, array) and returns a new value for accumulator
• accumulator [Any] Optional initial accumulator value

Examples

await reduce(
	['/foo', '/bar', '/baz'],
	async (accumulator, value) => {
		accumulator[v] = await fetch(value);
		return accumulator;
	},
	{}
);

Returns any final accumulator value

map

Invoke an async transform function on each item in the given Array in parallel, returning the resulting Array of mapped/transformed items.

This is an asynchronous, parallelized version of Array.prototype.map().

Parameters

• array Array The Array to map over
• mapper Function Async function, gets passed (value, index, array), returns the new value.

Examples

await map(
	['foo', 'baz'],
	async v => await fetch(v)
)

Returns Array resulting mapped/transformed values.

filter

Invoke an async filter function on each item in the given Array in parallel, returning an Array of values for which the filter function returned a truthy value.

This is an asynchronous, parallelized version of Array.prototype.filter().

Parameters

• array Array The Array to filter
• filterer Function Async function. Gets passed (value, index, array), returns true to keep the value in the resulting filtered Array.

Examples

await filter(
	['foo', 'baz'],
	async v => (await fetch(v)).ok
)

Returns Array resulting filtered values

parallel

Invoke all async functions in an Array or Object in parallel, returning the result.

Parameters

• list (Array<Function> | Object<Function>) Array/Object with values that are async functions to invoke.

Examples

await parallel([
	async () => await fetch('foo'),
	async () => await fetch('baz')
])

Returns (Array | Object) same structure as list input, but with values now resolved.

series

Invoke all async functions in an Array or Object sequentially, returning the result.

Parameters

• list (Array<Function> | Object<Function>) Array/Object with values that are async functions to invoke.

Examples

await series([
	async () => await fetch('foo'),
	async () => await fetch('baz')
])

Returns (Array | Object) same structure as list input, but with values now resolved.