entail

Entail is test runner for exported test from your ES modules. What sets it apart is that it does not require you to import some test library for defining tests - it just treats exports with certain naming convention as tests instead.

Convention

Tests

Functions exported by a name that starts with test are considered tests. Such functions will be passed common assertion functions

// You can use camel case naming
/** @type {import('entail').Test} */
export const testSum = (assert) => {
  assert.equal(1 + 1, 2)
}

// You can also use snake case naming
/** @type {import('entail').Test} */
export const test_multiply = (assert) => {
  assert.equal(2 * 2, 4)
}

// Or just use name `test`
/** @type {import('entail').Test} */
export const test = (assert) => {
  assert.throws(() => new Error('boom'))
}

Suites

Objects exported by a name that start with test are considered test suites. Properties of the suites are considered to be either a tests (function) or sub-suite.

export const test = {
  'multiply': (assert) => {
    assert.equal(2 * 2, 4)
  },
  'range check': (assert) => {
    assert.throws(() => new Uint8Array().set([1, 2]), /out of bound/)
  }
}

Skip

Tests prefixed with skip are accounted for but skipped by a test runner.

// You can use camel case naming
/** @type {import('entail').Test} */
export const skipTestSum = (assert) => {
  assert.equal(1 + 1, 2)
}

export const test = {
  'skip! multiply': (assert) => {
    assert.equal(2 * 2, 4)
  },
  'range check': (assert) => {
    assert.throws(() => new Uint8Array().set([1, 2]), /out of bound/)
  }
}

Only

In presence of tests prefixed with only all other tests are skipped by a test runner.

// You can use camel case naming
/** @type {import('entail').Test} */
export const onlyTestSum = (assert) => {
  assert.equal(1 + 1, 2)
}

export const test = {
  'only! multiply': (assert) => {
    assert.equal(2 * 2, 4)
  },
  'range check': (assert) => {
    assert.throws(() => new Uint8Array().set([1, 2]), /out of bound/)
  }
}

Usage

You can scan through all the modules in the working directory (excluding some common paths like node_modules) and run all discovered tests

entail

Or you can specify a specific pattern of your test files

entail test/*.spec.js

You do not even need to add entail as dependency you can simply run it

npx entail

You can also import entail and use it to test modules as follows

import test from 'entail'
import * testMath from './test/math.js'
import * testString from './test/string.js'

test({ testMath, testString })

node ./mytest.js

Credits

Initially this started as wrapper around superb uvu library. While uvu has mostly been replaced by entail's own components it would not have existed if uvu was not around.

Entail is envisioned as a successor of estest, from which idea of tests without frameworks came to be.