🖊 Logger

A light-weight, performant, and consistent approach to logging.

Table of contents

• Why use logger

• Install

• Usage

• Performance

• Core design principles

• Node version support

  • Why ES2018?

• Testing

• TODO

Why use logger

... as opposed to other loggers?

logger builds on pino to enable composable and re-usable logger implementations.

• Enforces a consistent approach to logging.
• Greatly reduces common boilerplate such as
  • logging metadata,
  • enforcing a consistent log format,
  • useful defaults, and more.
• It is written in TypeScript.

Install

npm install @hqoss/logger
# Additionally, for TypeScript users
npm install @types/pino --save-dev

⚠️ NOTE: The TypeScript compiler is configured to target ES2018 and the library uses commonjs for module resolution (for now). Read more about Node version support.

Usage

import { PinoLogger } from "@hqoss/logger";

export default (correlationId: string) => new Logger({
  correlationId,
  base: { service: `${name}@${version}` },
});

Performance

TODO

Core design principles

• Code quality; The modules contained within this package may be used in mission-critical software, so it's important that the code is performant, secure, and battle-tested.

• Developer experience; Developers must be able to use this package with no significant barriers to entry. It has to be easy-to-find, well-documented, and pleasant to use.

• Modularity & Configurability; It's important that our colleagues can compose, and easily change the ways in which they use this package.

Node version support

The TypeScript compiler is configured to target ES2018. In practice, this means projects consuming this package should run on Node 12 or higher, unless additional compilation/transpilation steps are in place to ensure compatibility with the target runtime.

Please see https://node.green/#ES2018 for reference.

Why ES2018?

Firstly, according to the official Node release schedule, Node 12.x entered LTS on 2019-10-21 and is scheduled to enter Maintenance on 2020-10-20. With the End-of-Life scheduled for April 2022, we are confident that most users will be running 12.x or higher.

Secondly, the 7.3 release of V8 (ships with Node 12.x or higher) includes "zero-cost async stack traces".

From the release notes:

We are turning on the --async-stack-traces flag by default. Zero-cost async stack traces make it easier to diagnose problems in production with heavily asynchronous code, as the error.stack property that is usually sent to log files/services now provides more insight into what caused the problem.

Testing

Ava and Jest were considered. Jest was chosen as it is easy to configure and includes most advanced features out of the box.

Prefer using Nock over mocking.

TODO

A quick and dirty tech debt tracker before we move to Issues.

• [ ] Write contributing guide
• [ ] Complete testing section, add best practices
• [ ] Describe scripts and usage, add best practices
• [ ] Add typespec and generate docs
• [ ] Describe security best practices, e.g. npm doctor, npm audit, npm outdated, ignore-scripts in .npmrc, etc.
• [ ] Add "Why should I use this" section
• [ ] Library architectural design (+ diagram?)