# errlop

> An extended Error class that envelops a parent error, such that the stack trace contains the causation

Latest version **8.5.0** (published 2025-08-08) · Artistic-2.0 license · 0 weekly downloads

## Install

```sh
npm install errlop
pnpm add errlop
yarn add errlop
bun add errlop
```

## Health

**Score 55/100 (C)** — status: stable.

Positive: has types; esm support; no vulnerabilities; high maintenance score; high quality score.

Warnings: low downloads.

Negative: stale.

## Facts

| | |
|---|---|
| Version | 8.5.0 |
| Published | 2025-08-08 |
| First published | 2018-07-22 |
| Weekly downloads | 0 |
| License | Artistic-2.0 |
| TypeScript types | bundled |
| Module format | ESM + CommonJS |
| Node | >=4 |
| Dependencies | 1 |
| Unpacked size | 83 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 9 |
| Author | Benjamin Lupton |
| Maintainers | bevryme |
| Keywords | browser, deno, deno-edition, deno-entry, denoland, error, es2017, es2024, es5, export-default, module, nerror, nested, nested-error, node, ono, simple, typed, types, typescript, verror |

## Links

- npm: https://www.npmjs.com/package/errlop
- Repository: https://github.com/bevry/errlop
- Issues: https://github.com/bevry/errlop/issues
- Funding: https://bevry.me/fund
- npm.io page: https://npm.io/package/errlop

## Dependencies (1)

- [editions](https://npm.io/package/editions.md) ^6.21.0

## Alternatives

- [@sentry/react-native](https://npm.io/package/@sentry/react-native.md) — 2.6M weekly downloads
- [@ardatan/aggregate-error](https://npm.io/package/@ardatan/aggregate-error.md) — 708.1K weekly downloads
- [custom-error-generator](https://npm.io/package/custom-error-generator.md) — 2.0K weekly downloads
- [@technik-sde/prosemirror-recreate-transform](https://npm.io/package/@technik-sde/prosemirror-recreate-transform.md) — 1.5K weekly downloads
- [@suchipi/error-utils](https://npm.io/package/@suchipi/error-utils.md) — 78 weekly downloads

## Recent versions

- 8.5.0 (latest) — 2025-08-08
- 8.5.0-next.1754625187.038350b68d94eaa5a85d2d304fa06454e2143e59 (next) — 2025-08-08
- 8.4.0 — 2023-12-28
- 8.4.0-next.1703775386.caba623ed5afdca4e17680071e844ccfe5caa793 — 2023-12-28
- 8.3.0 — 2023-12-27
- 8.3.0-next.1703646867.0487e7830292571048595f731f92688375d28671 — 2023-12-27
- 8.2.0 — 2023-12-05
- 8.2.0-next.1701788859.abb319b3257028a7e0e07b1c8faf042081f99d9d — 2023-12-05
- 8.1.0 — 2023-12-05
- 8.1.0-next.1701775122.29c91712991d62e2ad1db53831682f9f22b02948 — 2023-12-05
- 8.0.0 — 2023-11-30
- 8.0.0-next.1701325843.bd5642fea53ba29d06f6210107e181750d36cee3 — 2023-11-30
- 7.5.0 — 2023-11-29
- 7.5.0-next.1701239657.c7f06bc3e99d9b495ed8bdfc71788a6a1e5dd686 — 2023-11-29
- 7.4.0 — 2023-11-24
- … 97 more at https://npm.io/package/errlop/versions

## README

<!-- TITLE/ -->

# errlop

<!-- /TITLE -->

<!-- BADGES/ -->

<span class="badge-githubworkflow"><a href="https://github.com/bevry/errlop/actions?query=workflow%3Abevry" title="View the status of this project's GitHub Workflow: bevry"><img src="https://github.com/bevry/errlop/workflows/bevry/badge.svg" alt="Status of the GitHub Workflow: bevry" /></a></span>
<span class="badge-npmversion"><a href="https://npmjs.org/package/errlop" title="View this project on NPM"><img src="https://img.shields.io/npm/v/errlop.svg" alt="NPM version" /></a></span>
<span class="badge-npmdownloads"><a href="https://npmjs.org/package/errlop" title="View this project on NPM"><img src="https://img.shields.io/npm/dm/errlop.svg" alt="NPM downloads" /></a></span>
<br class="badge-separator" />
<span class="badge-githubsponsors"><a href="https://github.com/sponsors/balupton" title="Donate to this project using GitHub Sponsors"><img src="https://img.shields.io/badge/github-donate-yellow.svg" alt="GitHub Sponsors donate button" /></a></span>
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<br class="badge-separator" />
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<!-- /BADGES -->

<!-- DESCRIPTION/ -->

An extended Error class that envelops a parent error, such that the stack trace contains the causation

<!-- /DESCRIPTION -->


## Usage

[Complete API Documentation.](http://master.errlop.bevry.surge.sh/docs/)

```javascript
// const Errlop = require('errlop').default
import Errlop from 'errlop'
const a = new Errlop('AError')
const b = new Errlop('BError', a)
const c = Errlop.create('CError', b)
console.log(c.stack)
/*
Error: CError
    at Function.create (/Users/balupton/Projects/active/errlop/source/index.js:92:10)
    at Object.<anonymous> (/Users/balupton/Projects/active/errlop/example.js:6:18)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:266:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:596:3)
↳ Error: BError
    at Object.<anonymous> (/Users/balupton/Projects/active/errlop/example.js:5:11)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:266:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:596:3)
↳ Error: AError
    at Object.<anonymous> (/Users/balupton/Projects/active/errlop/example.js:4:11)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:266:19)
*/
console.log(c.orphanStack)
/*
Error: CError
    at Function.create (/Users/balupton/Projects/active/errlop/source/index.js:92:10)
    at Object.<anonymous> (/Users/balupton/Projects/active/errlop/example.js:6:18)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:266:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:596:3)
*/
```

<!-- INSTALL/ -->

## Install

### [npm](https://npmjs.com "npm is a package manager for javascript")

-   Install: `npm install --save errlop`
-   Import: `import pkg from ('errlop')`
-   Require: `const pkg = require('errlop').default`

### [Deno](https://deno.land "Deno is a secure runtime for JavaScript and TypeScript, it is an alternative for Node.js")

``` typescript
import pkg from 'https://unpkg.com/errlop@^8.5.0/edition-deno/index.ts'
```
### [Skypack](https://www.skypack.dev "Skypack is a JavaScript Delivery Network for modern web apps")

``` html
<script type="module">
    import pkg from '//cdn.skypack.dev/errlop@^8.5.0'
</script>
```
### [unpkg](https://unpkg.com "unpkg is a fast, global content delivery network for everything on npm")

``` html
<script type="module">
    import pkg from '//unpkg.com/errlop@^8.5.0'
</script>
```
### [jspm](https://jspm.io "Native ES Modules CDN")

``` html
<script type="module">
    import pkg from '//dev.jspm.io/errlop@8.5.0'
</script>
```
### [Editions](https://editions.bevry.me "Editions are the best way to produce and consume packages you care about.")

This package is published with the following editions:
-   `errlop` aliases `errlop/index.cjs` which uses the [Editions Autoloader](https://github.com/bevry/editions "You can use the Editions Autoloader to autoload the appropriate edition for your consumers environment") to automatically select the correct edition for the consumer's environment
-   `errlop/source/index.ts` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") source code with [Import](https://babeljs.io/docs/learn-es2015/#modules "ECMAScript Modules") for modules
-   `errlop/edition-browsers/index.js` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled against [ES2024](https://en.wikipedia.org/wiki/ES2024 "ECMAScript 2024") for web browsers with [Import](https://babeljs.io/docs/learn-es2015/#modules "ECMAScript Modules") for modules
-   `errlop/edition-es2024/index.js` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled against [ES2024](https://en.wikipedia.org/wiki/ES2024 "ECMAScript 2024") for [Node.js](https://nodejs.org "Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine") 14 || 16 || 18 || 20 || 22 || 24 with [Require](https://nodejs.org/dist/latest-v5.x/docs/api/modules.html "Node/CJS Modules") for modules
-   `errlop/edition-es2017/index.js` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled against [ES2017](https://en.wikipedia.org/wiki/ES2017 "ECMAScript 2017") for [Node.js](https://nodejs.org "Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine") 6 || 8 || 10 || 12 || 14 || 16 || 18 || 20 || 22 || 24 with [Require](https://nodejs.org/dist/latest-v5.x/docs/api/modules.html "Node/CJS Modules") for modules
-   `errlop/edition-es5/index.js` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled against ES5 for [Node.js](https://nodejs.org "Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine") 4 || 6 || 8 || 10 || 12 || 14 || 16 || 18 || 20 || 22 || 24 with [Require](https://nodejs.org/dist/latest-v5.x/docs/api/modules.html "Node/CJS Modules") for modules
-   `errlop/edition-es2017-esm/index.js` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled against [ES2017](https://en.wikipedia.org/wiki/ES2017 "ECMAScript 2017") for [Node.js](https://nodejs.org "Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine") 12 || 14 || 16 || 18 || 20 || 22 || 24 with [Import](https://babeljs.io/docs/learn-es2015/#modules "ECMAScript Modules") for modules
-   `errlop/edition-types/index.d.ts` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") compiled Types with [Import](https://babeljs.io/docs/learn-es2015/#modules "ECMAScript Modules") for modules
-   `errlop/edition-deno/index.ts` is [TypeScript](https://www.typescriptlang.org/ "TypeScript is a typed superset of JavaScript that compiles to plain JavaScript.") source code made to be compatible with [Deno](https://deno.land "Deno is a secure runtime for JavaScript and TypeScript, it is an alternative to Node.js")

<!-- /INSTALL -->

<!-- HISTORY/ -->

## History

[Discover the release history by heading on over to the `HISTORY.md` file.](https://github.com/bevry/errlop/blob/HEAD/HISTORY.md#files)

<!-- /HISTORY -->

<!-- BACKERS/ -->

## Backers

### Code

[Discover how to contribute via the `CONTRIBUTING.md` file.](https://github.com/bevry/errlop/blob/HEAD/CONTRIBUTING.md#files)

#### Authors

-   [Benjamin Lupton](https://balupton.com) — Accelerating collaborative wisdom.

#### Maintainers

-   [Benjamin Lupton](https://balupton.com) — Accelerating collaborative wisdom.

#### Contributors

-   [Benjamin Lupton](https://github.com/balupton) — [view contributions](https://github.com/bevry/errlop/commits?author=balupton "View the GitHub contributions of Benjamin Lupton on repository bevry/errlop")

### Finances

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#### Sponsors

-   [Andrew Nesbitt](https://nesbitt.io) — Working on mapping the world of open source software @ecosyste-ms  and empowering developers with @octobox
-   [Divinci ™](https://divinci.ai) — A more comfortable AI conversation experience, with friends! 🤖🖤
-   [Mr. Henry](https://mrhenry.be)
-   [Poonacha Medappa](https://poonachamedappa.com)
-   [Roboflow](https://roboflow.com)
-   [Square](https://github.com/square)

#### Donors

-   [Andrew Nesbitt](https://nesbitt.io)
-   [Ángel González](https://univunix.com)
-   [Arjun Aditya](https://arjunaditya.xyz)
-   [Armen Mkrtchian](https://mogoni.dev)
-   [Balsa](https://balsa.com)
-   [Canonical](https://canonical.com)
-   [Chad](https://opencollective.com/chad8)
-   [Codecov](https://codecov.io)
-   [Divinci ™](https://divinci.ai)
-   [dr.dimitru](https://veliovgroup.com)
-   [Elliott Ditman](https://elliottditman.com)
-   [entroniq](https://gitlab.com/entroniq)
-   [Frontend Masters](https://FrontendMasters.com)
-   [GitHub](https://github.com/about)
-   [Hunter Beast](https://cryptoquick.com)
-   [Jean-Luc Geering](https://github.com/jlgeering)
-   [Lee Driscoll](https://leedriscoll.me)
-   [Michael Duane Mooring](https://divinci.app)
-   [Michael Harry Scepaniak](https://michaelscepaniak.com)
-   [Mohammed Shah](https://github.com/smashah)
-   [Mr. Henry](https://mrhenry.be)
-   [Pleo](https://pleo.io)
-   [Poonacha Medappa](https://poonachamedappa.com)
-   [Robert de Forest](https://github.com/rdeforest)
-   [Rob Morris](https://linktr.ee/recipromancer)
-   [Roboflow](https://roboflow.com)
-   [Scott Kempson](https://github.com/scokem)
-   [Sentry](https://sentry.io)
-   [ServieJS](https://github.com/serviejs)
-   [Skunk Team](https://skunk.team)
-   [Square](https://github.com/square)
-   [Syntax](https://syntax.fm)
-   [WriterJohnBuck](https://github.com/WriterJohnBuck)

<!-- /BACKERS -->

<!-- LICENSE/ -->

## License

Unless stated otherwise all works are:

-   Copyright &copy; [Benjamin Lupton](https://balupton.com)

and licensed under:

-   [Artistic License 2.0](http://spdx.org/licenses/Artistic-2.0.html)

<!-- /LICENSE -->

---
_Source: https://npm.io/package/errlop · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._