Skip to documentation
ALEXANDRONET

package

@stackline/fault 1.0.3 — installation and API

Functional errors with formatted output

Install @stackline/fault

npm install @stackline/[email protected]

Package version: 1.0.3. Metadata verified: 2026-11-12. This is separate from the framework version and demonstration runtime.

Node.js requirement
{}
Accepted peer dependencies (declared ranges)
{}

Tested environments are described in the versioned README and linked source checks. A declared peer range is not evidence that every version in it was tested.

Versioned reference

This reference comes from the published @stackline/[email protected] README. Its upstream attribution and license remain with the source. Benchmark and security statements describe the cited tests and advisories, not a guarantee for every application.

@stackline/fault

Functional errors with formatted output.

Documentation | npm | Issues | Repository

Current package version: 1.0.3

Why this package?

@stackline/fault is the Stackline-maintained distribution of [email protected]. It is an independent continuation of fault; original authors and licenses remain credited below.

Compatibility

Item Value
Package @stackline/[email protected]
API target [email protected]
Supported Node.js See supported framework requirements
License MIT
Module type module
Main entry index.js
Types index.d.ts
Runtime dependencies format

Installation

npm install @stackline/fault

Preserve existing imports and plugin resolution with an npm alias:

npm install fault@npm:@stackline/fault

Usage and API reference

fault

Functional errors with formatted output.

Contents

What is this?

This package adds printf-like interpolation to errors.

When should I use this?

This package useful when you frequently display parameters in error messages and manual string concatenation is becoming verbose.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install @stackline/fault

In Deno with Skypack:

import {fault} from 'https://cdn.skypack.dev/fault@2?dts'

In browsers with Skypack:

<script type="module">
  import {fault} from 'https://cdn.skypack.dev/fault@2?min'
</script>

Use

import {fault} from '@stackline/fault'

throw fault('Hello %s!', 'Eric')

Yields:

Error: Hello Eric!
    at FormattedError (~/node_modules/fault/index.js:30:12)
    at Object.<anonymous> (~/example.js:3:7)
    …

Or, format a float in a type error:

import {fault} from '@stackline/fault'

throw fault.type('Who doesn’t like %f? 🍰', Math.PI)

Yields:

TypeError: Who doesn’t like 3.141593? 🍰
    at Function.FormattedError [as type] (~/node_modules/fault/index.js:30:12)
    at Object.<anonymous> (~/example.js:3:7)

API

This package exports the following identifiers: fault and create. There is no default export.

fault(format?[, values…])

Create an error with a printf-like formatted message.

Parameters
  • format (string, optional) — template string
  • values (*, optional) — values to render in format
Returns

An Error instance.

Formatters

The following formatters are supported in format:

  • %s — string
  • %b — binary
  • %c — character
  • %d — decimal
  • %f — floating point
  • %o — octal
  • %x — lowercase hexadecimal
  • %X — uppercase hexadecimal
  • % followed by any other character, prints that character

See samsonjs/format for argument parsing.

Other errors

create(Constructor)

Factory to create instances of ErrorConstructor with support for formatting. Used internally to wrap the global error constructors and exposed for custom errors. Returns a function just like fault.

Types

This package is fully typed with TypeScript. There are no extra exported types.

Compatibility

This package is at least compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, and 16.0+. It also works in Deno and modern browsers.

Security

This package is safe.

Contribute

Yes please! See How to Contribute to Open Source.

License

MIT © Titus Wormer

Credits and original authors

Original copyright, license notices and contributor acknowledgements remain part of this distribution. Stackline maintenance does not replace authorship of the original work.

Use this repository's issue tracker for reproducible bugs and feature requests. Join r/Stackline for examples, usage questions and release discussions.