log-bundler

0.5.4 verified Sat Apr 25 auth: no javascript

A JavaScript/TypeScript library that collects multiple log messages and emits them as a single JSON log line. Version 0.5.4 is the latest stable release; the project is pre-1.0.0 with documentation promised at 1.0.0. It simplifies structured logging by buffering logs and flushing them as a batch, ideal for reducing I/O in high-throughput Node.js applications. Simpler than full-featured frameworks like Winston or Pino, but limited in features and currently lacks comprehensive docs.

Common errors

error TypeError: log_bundler_1.default is not a constructor ↓

cause Using default import in ESM with older version (<0.5.0) or incorrect import style.

fix

Use named import: import { LogBundler } from 'log-bundler'

error ERR_REQUIRE_ESM ↓

cause Using require() with an ESM-only package version.

fix

Use import syntax or convert your project to ESM. Alternatively, for CommonJS, use dynamic import: const { LogBundler } = await import('log-bundler')

error Cannot find module 'log-bundler' ↓

cause Package not installed or incorrect import path.

fix

Run: npm install log-bundler

error Property 'log' does not exist on type 'typeof import(...)' ↓

cause TypeScript not recognizing instance methods due to wrong import (importing the class instead of an instance).

fix

Instantiate LogBundler first: const bundler = new LogBundler(); then call bundler.log()

Warnings

gotcha Pre-1.0.0 API may break in minor versions. Semantic versioning not guaranteed. ↓

fix Pin to exact version or prepare for breaking changes.

deprecated Certain configuration options (e.g., 'outputFile') may be removed in future releases. ↓

fix Use standard output streams instead of custom output file option.

gotcha Calling flush() synchronously may emit logs asynchronously; ensure proper await if flush returns a promise. ↓

fix Use 'await bundler.flush()' if flush() returns a promise.

breaking Version 0.5.0 changed the export from default to named exports. 'require('log-bundler')' no longer returns a constructor. ↓

fix Use 'import { LogBundler } from 'log-bundler'' or 'const { LogBundler } = require('log-bundler')'.

gotcha Log levels are case-sensitive and must be lowercase ('info', 'error'). Using uppercase 'INFO' will not filter correctly. ↓

fix Always use lowercase level strings.

Install

npm install log-bundler

yarn add log-bundler

pnpm add log-bundler

Imports

LogBundler
wrong
```
const LogBundler = require('log-bundler').LogBundler
```
correct
```
import { LogBundler } from 'log-bundler'
```
The library exports LogBundler as a named export. Default import is not supported.

createLogBundler

wrong

const createLogBundler = require('log-bundler').default

correct

import { createLogBundler } from 'log-bundler'

Helper function to create a LogBundler instance. Not a default export.

LogBundlerOptions

wrong

import { LogBundlerOptions } from 'log-bundler' (when only type used)

correct

import type { LogBundlerOptions } from 'log-bundler'

Type import available for TypeScript users. Avoid value import at runtime.

Quickstart

Show how to create a LogBundler, add individual logs, and flush them as a batch JSON log.

import { LogBundler } from 'log-bundler';

const bundler = new LogBundler({
  batchSize: 10,
  flushInterval: 1000,
  level: 'info'
});

bundler.log('info', 'This is a log message', { userId: 123 });
bundler.log('error', 'An error occurred', { errorCode: 500 });

// Manually flush to write bundled logs
bundler.flush();