Function handler

test/internals/server.test.js:9–12

(req, res)

const { createServer } = require('../../lib/server')

const handler = (req, res) => {
  res.writeHead(200, { 'Content-Type': 'application/json' })
  res.end(JSON.stringify({ data: 'Hello World!' }))
}

test('start listening', async t => {
  const { server, listen } = createServer({}, handler)