test.js

const { parse } = require('url')
const { decode } = require('querystring')
const { unflatten } = require('flat')

const dbUriParse = (url) => {
  let options = { connection: {} }
  const u = parse(url)
  const { protocol, pathname, hostname, auth, query, port } = u

  options.client = protocol.replace(':', '')
  if (options.client === 'sqlite') {
    options.client = 'sqlite3'
  } else if (options.client === 'postgres' || options.client === 'postgresql') {
    options.client = 'pg'
  }

  if (options.client === 'sqlite3') {
    options.connection.filename = hostname && pathname ? `${hostname}${pathname}` : (hostname || pathname)
    if (options.connection.filename === '/:memory') {
      options.connection.filename = ':memory:'
    }
  } else {
    const [user, password] = auth ? auth.split(':') : []
    options.connection = {
      database: pathname.replace(/^\//, ''),
      host: hostname,
      user,
      password,
      port
    }
  }

  if (query) {
    const q = decode(query)
    const qoptions = {}
    Object.keys(q).forEach(k => {
      qoptions[k] = q[k]
      if (q[k] === 'false') {
        qoptions[k] = false
      }
      if (q[k] === 'true') {
        qoptions[k] = true
      }
      if (!isNaN(q[k])) {
        qoptions[k] = Number(q[k])
      }
    })
    options = { ...options, ...unflatten(qoptions) }
  }

  return options
}

const urls = `postgres://username@hostname/databasename
mysql://username:password@hostname:666/databasename
postgres:///var/run/postgresql/test?debug=1
mysql://localhost/database?unix_socket=/var/lib/mysql/socket
sqlite://path/to/file
sqlite://file?useNullAsDefault=true
sqlite://:memory:?useNullAsDefault=true`

urls.split('\n').forEach(s => {
  test(s, () => {
    expect(dbUriParse(s)).toMatchSnapshot()
  })
})