src/index.js
function presetResolver (opts) {
  const presets = arrayify(opts.presets || opts.extends)

  if (presets.length > 0) {
    const arg = Object.assign({}, opts)
    const options = Object.assign({ first: arg }, opts)
    const tasks = resolvePlugins(presets, options).reduce(
      (acc, preset) => presetReducer(acc, preset),
      {}
    )

    return transformTasks(opts, Object.assign({}, tasks, opts.tasks))
  }

  return transformTasks(opts, opts.tasks)
}
function presetResolver (opts) {
  const presets = arrayify(opts.presets || opts.extends)

  if (presets.length > 0) {
    const arg = Object.assign({}, opts)
    const options = Object.assign({ first: arg }, opts)
    const tasks = resolvePlugins(presets, options).reduce(
      (acc, preset) => presetReducer(acc, preset),
      {}
    )

    return transformTasks(opts, Object.assign({}, tasks, opts.tasks))
  }

  return transformTasks(opts, opts.tasks)
}
todo: externalize as `hela-resolver`?