dry-utils-async

A collection of async utilities for handling common asynchronous programming patterns.

I do not anticipate that you will find this repository useful. It is hyper-specific to my needs. If you do find something useful, feel free to use it, fork it, or liberally copy code out into your own projects.

Installation

Prerequisites:

• Node.js >=22.0.0

Install:

npm install dry-utils-async

Features

• Batch Processing: Process arrays of items in controlled batches with built-in error handling.
• Logging: Emits events for async operations via node:diagnostics_channel.

Usage

Batch Processing

Process an array of items in batches with controlled concurrency:

import { batch } from "dry-utils-async";

// Example: Process user IDs in batches of 3
const userIds = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];

await batch(
  "ProcessUsers", // Operation name for logging
  userIds, // Array of values to process
  async (id) => {
    // Async function to process each value
    const user = await fetchUser(id);
    await updateUserStatus(user);
  },
  3 // Batch size (3 concurrent operations)
);

Subscribing to Logging Events

This package uses node:diagnostics_channel to publish log and error events. A helper function subscribeAsyncLogging is provided to simplify subscribing to these events.

The subscribeAsyncLogging function accepts an object with optional log and error callbacks. Each callback receives a message object with { tag: string, val: unknown }.

Here is an example of how to subscribe to events from the batch function.

import { subscribeAsyncLogging } from "dry-utils-async";

// Subscribe to log and error events
subscribeAsyncLogging({
  log: ({ tag, val }) => {
    // Example: [LOG] Batch_ProcessUsers: 10
    // Example: [LOG] Batch_ProcessUsers: Complete
    console.log(`[LOG] ${tag}:`, val);
  },
  error: ({ tag, val }) => {
    // Example: [ERROR] Batch_ProcessUsers: at values[4]: Error: Invalid ID: -5
    console.error(`[ERROR] ${tag}:`, val);
  },
});