opt-vitest

Vitest matchers for opt.

Usage

To install the new matchers, import this package into your test file:

import "@bodil/opt-vitest";

This extends Vitest's expect object with four methods: isSome(), isNone(), isOk() and isErr().

All of these can be called without arguments, which will assert only that the value under inspection is of the expected type. You can also pass an expected value, which will be checked for equality with the value contained within the Result or Option, or you can pass a function which will be passed the contained value as its first and only argument, inside which you could do further expecting, or throw an error to fail the test.

Example

const okValue: Result<string, Error> = Ok("all good!");

expect(okValue).isOk();
expect(okValue).not.isErr();
expect(okValue).isOk("all good!");
expect(okValue).isOk((value) => expect(value).eq("all good!));

Licence

Copyright 2023 Bodil Stokke

This software is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.