!@thi.ng/errors

!npm downloads

> [!NOTE]
> This is one of 214 standalone projects, maintained as part
> of the @thi.ng/umbrella monorepo
> and anti-framework.
>
> 🚀 Please help me to work full-time on these projects by sponsoring me on
> GitHub. Thank you! ❤️

- About
- Status
- Installation
- Dependencies
- Usage examples
- API
- Environment variables
- Authors
- License

About

Custom error types and error factory functions.

This package defines the following error types & helper functions to throw them:

- AssertionError
- IllegalArgumentError
- IllegalArityError
- IllegalStateError
- OutOfBoundsError
- UnsupportedOperationError

Custom error types can be easily defined using
defError().

Status

STABLE - used in production

Search or submit any issues for this package

Installation

``bash
yarn add @thi.ng/errors
`

ESM import:

`ts
import * as err from "@thi.ng/errors";
`

Browser ESM import:

`html

`

JSDelivr documentation

For Node.js REPL:

`js
const err = await import("@thi.ng/errors");
`

Package sizes (brotli'd, pre-treeshake): ESM: 849 bytes

Dependencies

None

Usage examples

One project in this repo's
/examples
directory is using this package:

| Description | Live demo | Source |
|:-----------------------------------------------------------------------------|:---------------------------------------------------|:--------------------------------------------------------------------------------|
| GPU-based data reduction using thi.ng/shader-ast & WebGL multi-pass pipeline | Demo | Source |

API

Generated API docs

`ts
import * as err from "@thi.ng/errors";

err.illegalArity(3)
// Error: illegal arity: 3

err.illegalArgs("expected foo");
// Error: illegal argument(s): expected foo

err.illegalState("oops");
// Error: illegal state: oops

err.unsupported("TODO not yet implemented")
// Error: unsupported operation: TODO not yet implemented

// define custom error
const MyError = err.defError(
() => "Eeek... ",
(x) => x + " is not allowed!"
);

try {
throw new MyError(23);
} catch(e) {
console.warn(e.message);
console.log(e instanceof Error);
}
// Eeek... 23 is not allowed!
// true
`

$3

The UMBRELLA_ASSERTS or VITE_UMBRELLA_ASSERTS env variables are
used to control the behavior of the assert() function in production builds: If
either is set (to a non-empty string), the function will always be enabled.
Otherwise (by default), assert() will be disabled for production builds,
i.e. if process.env.NODE_ENV === "production".

Authors

- Karsten Schmidt

If this project contributes to an academic publication, please cite it as:

`bibtex
@misc{thing-errors,
title = "@thi.ng/errors",
author = "Karsten Schmidt",
note = "https://thi.ng/errors",
year = 2018
}
``

License

© 2018 - 2026 Karsten Schmidt // Apache License 2.0