An extremely fast and lightweight test runner for Node.js and the browser

uvu is an extremely fast and lightweight test runner for Node.js and the browser
Ultimate Velocity, Unleashed

Features

• Super lightweight
• Extremely performant
• Individually executable test files
• Supports async/await tests
• Supports native ES Modules
• Browser-Compatible
• Familiar API

Install

$ npm install --save-dev uvu

Usage

Check out /examples for a list of working demos!

// tests/demo.js
import { test } from 'uvu';
import * as assert from 'uvu/assert';

test('Math.sqrt()', () => {
  assert.is(Math.sqrt(4), 2);
  assert.is(Math.sqrt(144), 12);
  assert.is(Math.sqrt(2), Math.SQRT2);
});

test('JSON', () => {
  const input = {
    foo: 'hello',
    bar: 'world'
  };

  const output = JSON.stringify(input);

  assert.snapshot(output, `{"foo":"hello","bar":"world"}`);
  assert.equal(JSON.parse(output), input, 'matches original');
});

test.run();

Then execute this test file:

# via `uvu` cli, for all `/tests/**` files
$ uvu -r esm tests

# via `node` directly, for file isolation
$ node -r esm tests/demo.js

View the uvu CLI documentation

Assertions

The uvu/assert module is completely optional.

In fact, you may use any assertion library, including Node’s native [assert](https://nodejs.org/api/assert.html) module! This works because uvu relies on thrown Errors to detect failures. Implicitly, this also means that any uncaught exceptions and/or unhandled Promise rejections will result in a failure, which is what you want!

API

Module: uvu

View uvu API documentation

The main entry from which you will import the test or suite methods.

Module: uvu/assert

View uvu/assert API documentation

A collection of assertion methods to use within your tests. Please note that:

• these are browser compatible
• these are completely optional

Benchmarks

via the /bench directory with Node v10.21.0

Below you’ll find each test runner with two timing values:

• the took ___ value is the total process execution time – from startup to termination
• the parenthesis value ((___)) is the self-reported execution time, if known

Each test runner’s stdout is printed to the console to verify all assertions pass.

Said output is excluded below for brevity.

~> "ava"   took   594ms  (  ???  )
~> "jest"  took   962ms  (356  ms)
~> "mocha" took   209ms  (  4  ms)
~> "tape"  took   122ms  (  ???  )
~> "uvu"   took    72ms  (  1.3ms)

Download Details:

Author: lukeed

GitHub: https://github.com/lukeed/uvu

#nodejs #javascript