@smallwins/err

Slightly better custom Errors

• Same runtime interface: just pass a message to the constructor
• Respects extends with clean name and stack properties
• Adds toObject returns a plain object representation
• Bundles common HTTP error types with a code property

npm i @smallwins/err --save

Bundled Error Types

• err.Err a base Error type intended for extending
• err.InternalError has a code property of 500
• err.DatabaseError has a code property of 500
• err.NotFoundError has a code property of 404
• err.NotAuthorizedError has a code property of 403

Usage

Example usage:

var err = require('@smallwins/err')

let notFound = new err.NotFoundError('missing record')
console.log(err.code) // logs 404

Subclass to add additional properties such as code:

var err = require('@smallwins/err')

class CoffeeError extends err.Err {
  constructor(params) {
    super(params)
    this.code = 500
  }
}

let e = new CoffeeError('lactose intolerant')
console.log(e.code) // logs 500

Get a clean representation:

console.log(e.toObject())
// logs {name, code, message, stack}

Extend by requireing error directly:

var Err = require('@smallwins/err/err')

class TerribleError extends Err {
  constructor(msg) {
    super(msg)
    this.extra = 'extra info'
  }
}

var e = new TerribleError('wut')
console.log(e.extra)

Work oldschool without new:

var err = require('@smallwins/err/oldschool')

console.log(err.Err('basic') instanceof Error)
// logs true

console.log(err.NotFound('not found err').toString())
// logs NotFound: not found err

@smallwins/err/oldschool API

Factory functions which return real Error instances:

• err.Err returns an Err instance
• err.Internal returns an InternalError instance
• err.Database returns a DatabaseError instance
• err.NotFound returns a NotFoundError instance
• err.NotAuthorized returns a NotAuthorizedError instance

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Runtime type checking fully supported. Check the tests.