lambda-tree

Lambda Tree - a place for logs 🌳🪵

A lightweight library designed to make AWS Lambda logs easier and well formed. Kill sloppy logs by using lambda-tree.

Motivation

Lambda debug can cause you to use more console.log calls than you want to admit. Admit it!! Eventually the logging gets messy. This library will help produce logs which are just easier to manage long term.

Installation

The recommended way to install the anticipated.io SDK is through npm or Yarn. The library is exposed as CommonJS and ESM.

npm:

npm install lambda-tree

yarn:

yarn add lambda-tree

Usage

The entire point of lambda-tree is simplicity with the goal of producing well-formed logs in JSON to AWS CloudWatch.

Example Usage:

const log = new Log({ context })
log.info({ message: 'a simple log message' })
log.error({ error: 'oh no, bad' })

TypeScript example:

interface LogInfo {
  user: string
  company: string
  operation: string
}

const log = new Log<LogInfo>({ context })
log.info({ message: 'customer enabled', user, company, operation })

Output

Example output might be as follows:

{
  "level": "info",
  "requestId": "123",
  "message": "user enabled",
  "user": { "name": "John", "age": 30, "phone": "1234567890" }
}

Which was produced via:

interface UserInfo {
  name: string
  age: number
  phone: string
}

const log = new Log<UserInfo>({ context })
const user: UserInfo = { name: 'John', age: 30, phone: '1234567890' }
log.info({ message: 'user enabled', ...user })

Tagging

There is also a built-in system for tagging log entries. Methods addTag and removeTag are provided. A simple tagging might look like this:

const log = new Log({ context }).addTag('user')
const user = { username: 'bob' }
log.info({ message: 'user added', ...user })

would produce the following:

{ "level": "info", "requestId": "123", "message": "user added", "username": "bob", "tags": ["user"] }

Tests

Tests are executed via Jest.

npm run test

Changelog

[1.1.0] - 2022-11-24

BREAKING CHANGE Changed opinion on "message" thus updating the API to make calling the function(s) easier on the caller broadly