port-get/test.js

Get an available TCP port (a minimal CJS module)

'use strict'
const { createServer } = require('net')
const portGet = require('.')
const { test } = require('brittle')

test('any port', async ({ is, execution }) => {
  const port = await portGet()
  is(typeof port, 'number')
  const server = createServer().unref()
  await execution(new Promise((resolve) => server.listen(port, '127.0.0.1', resolve)))
  is(server.address().port, port)
})

test('specified port', async ({ is }) => {
  const port = Math.floor(Math.random() * 1000 + 12000)
  is(await portGet(port), port)
})

test('unavailable', async ({ is, not, execution }) => {
  const target = Math.floor(Math.random() * 1000 + 12000)
  await execution(new Promise((resolve) => createServer().unref().listen(target, '127.0.0.1', resolve)))
  const port = await portGet(target)
  is(typeof port, 'number')
  not(port, target)
})

test('privileged', async ({ is, not }) => {
  const target = 80
  const port = await portGet(target)
  is(typeof port, 'number')
  not(port, target)
})

test('host', async ({ is, not, execution }) => {
  const target = Math.floor(Math.random() * 1000 + 12000)
  await execution(new Promise((resolve) => createServer().unref().listen(target, '0.0.0.0', resolve)))
  const port = await portGet(target, '0.0.0.0')
  is(typeof port, 'number')
  not(port, target)
  is(await portGet(target, '127.0.0.1'), target)
})

test('ports', async ({ is }) => {
  const targets = [Math.floor(Math.random() * 1000 + 12000), Math.floor(Math.random() * 1000 + 12000)]
  const port = await portGet(targets)
  is(port, targets[0])
})

test('ports: first port unavailable', async ({ is, execution }) => {
  const targets = [Math.floor(Math.random() * 1000 + 12000), Math.floor(Math.random() * 1000 + 12000)]
  await execution(new Promise((resolve) => createServer().unref().listen(targets[0], '127.0.0.1', resolve)))
  const port = await portGet(targets)
  is(port, targets[1])
})

test('ports: all ports unavailable', async ({ is, not, execution }) => {
  const targets = [Math.floor(Math.random() * 1000 + 12000), Math.floor(Math.random() * 1000 + 12000)]
  await execution(new Promise((resolve) => createServer().unref().listen(targets[0], '127.0.0.1', resolve)))
  await execution(new Promise((resolve) => createServer().unref().listen(targets[1], '127.0.0.1', resolve)))
  const port = await portGet(targets)
  is(typeof port, 'number')
  not(port, targets[0])
  not(port, targets[1])
})