eslint-plugin-pino

ESLint plugin to enforce correct pino logger usage patterns.

Installation

npm install --save-dev eslint-plugin-pino

Usage

Add pino to the plugins section of your .eslintrc configuration file:

{
  "plugins": ["pino"]
}

Then configure the rules you want to use under the rules section:

{
  "rules": {
    "pino/correct-args-position": "error"
  }
}

Recommended Configuration

You can use the recommended configuration which includes the most important rules:

{
  "extends": ["plugin:pino/recommended"]
}

Rules

correct-args-position

Enforces that pino logger methods have object arguments before the message string.

✅ Correct

logger.info({userId: 123}, 'User logged in');
logger.error({error: err, userId: 123}, 'Failed to process request');
logger.debug({data: result}, `Processing ${id} completed`);

❌ Incorrect

logger.info('User logged in', {userId: 123});
logger.error('Failed to process request', {error: err, userId: 123});
logger.debug(`Processing ${id} completed`, {data: result});

Why?

When using pino logger methods incorrectly (with the message before the object), the object arguments are treated as additional parameters and won't be included in the structured log output. This can result in lost context information that's crucial for debugging and monitoring.

The rule supports all pino logging methods:

• trace
• debug
• info
• warn
• error
• fatal
• child
• log

Auto-fix

This rule provides automatic fixing. When you run ESLint with the --fix flag, it will automatically reorder the arguments to put objects first, then the message, then any other arguments.

Development

# Install dependencies
npm install

# Run tests
npm test

# Build
npm run build

# Lint
npm run lint

License

MIT