errate

Converts a value into an Error of the specified type.

Installation

Requires Node.js 6.0.0 or above.

npm i errate

API

The module exports a single function.

Parameters

1. Optional: e (string, Error object, boolean, or null): The error message, or an existing Error object. If null or a boolean, the returned Error will have no message.
2. Optional: Cls (Error class): The desired class of the returned Error (such as TypeError or RangeError). Defaults to Error.
3. Optional: Object argument:
   • defaultMessage (string): The first argument that will be provided to the constructor if an Error object is being created (i.e. if e is true or “falsey”).
   • forceClass (boolean): If set to true, instances of other Error classes will be converted to instances of Cls. If set to false, Cls will only be used to wrap string errors. Defaults to true.

Return Value

An Error of the specified class.

Examples

Default Class With Message

const errate = require('errate')

const err = errate('Message')
err instanceof Error // true
err.message // 'Message'

Default Class Without Message

const errate = require('errate')

const err = errate()
err instanceof Error // true
err.message // ''

Error Subclass With Message

const errate = require('errate')

const err = errate('Message', TypeError)
err instanceof TypeError // true
err.message // 'Message'

Error Subclass Without Message

const errate = require('errate')

const err = errate(TypeError)
err instanceof TypeError // true
err.message // ''

Error Class Conversion

const errate = require('errate')

const err = errate(new TypeError('Message'), RangeError)
err instanceof RangeError // true
err.message // 'Message'