Awesome

<p align=center> AssertionError and AssertionResult classes. </p> <p align=center> <a href="https://github.com/chaijs/assertion-error/actions"> <img alt="build:?" src="https://github.com/chaijs/assertion-error/actions/workflows/nodejs.yml/badge.svg" /> </a><a href="https://www.npmjs.com/package/assertion-error"> <img alt="downloads:?" src="https://img.shields.io/npm/dm/assertion-error.svg" /> </a><a href=""> <img alt="devDependencies:none" src="https://img.shields.io/badge/dependencies-none-brightgreen" /> </a> </p>

What is AssertionError?

Assertion Error is a module that contains two classes: AssertionError, which is an instance of an Error, and AssertionResult which is not an instance of Error.

These can be useful for returning from a function - if the function "succeeds" return an AssertionResult and if the function fails return (or throw) an AssertionError.

Both AssertionError and AssertionResult implement the Result interface:

interface Result {
  name: "AssertionError" | "AssertionResult";
  ok: boolean;
  toJSON(...args: unknown[]): Record<string, unknown>;
}

So if a function returns AssertionResult | AssertionError it is easy to check which one is returned by checking either .name or .ok, or check instanceof Error.

Installation

Node.js

assertion-error is available on npm.

$ npm install --save assertion-error

Deno

assertion_error is available on Deno.land

import {
  AssertionError,
  AssertionResult,
} from "https://deno.land/x/assertion_error@2.0.0/mod.ts";