Avaq / oletus

Minimal ECMAScript Module test runner

▶ oletus

A zero configuration, zero dependency test runner for ECMAScript Modules—made specifically for getting started quick. Painless migration to the bigger guns if you end up needing them.

Test Syntax

import test from 'oletus'

// this should look pretty familiar
test('arrays are equal', t => {
  t.deepEqual([1, 2], [1, 2])
})

Usage

Add oletus to your project

Install it with npm:

npm install --save-dev oletus

Add the test script to your package.json, using the native --experimental-modules:

  "scripts": {
    "test": "npx -n='--experimental-modules --no-warnings' oletus"
  },

Alternatively, you can use the esm package for wider support:

  "scripts": {
    "test": "npx -n='-r esm' oletus"
  },

Create the tests

Write your test modules in a /test/ directory:

import test from 'oletus'

test('foo', t => {
  t.ok(true)
})

test('bar', async t => {
  const bar = Promise.resolve('bar')

  t.equal(await bar, 'bar')
})

---

Alternate test locations

It's also possible to run tests that match a pattern passed in as a command-line argument.

oletus src/**/*.test.mjs

---

npm test away!

Reporters

Oletus has a concise reporter on local runs and a verbose reporter on CI environments.

API

test(title, implementation)

The imported test is an async function that expects the title and implementation of the test to be passed in as arguments. The implementation has a single parameter (t, for example) that gets passed the strict node assertion module.

Author

Joonatan Vuorinen (@bearror)