setup-node/node_modules/before-after-hook/lib/register.js

module.exports = register

function register (state, name, method, options) {
  if (typeof method !== 'function') {
    throw new Error('method for before hook must be a function')
  }

  if (!options) {
    options = {}
  }

  if (Array.isArray(name)) {
    return name.reverse().reduce(function (callback, name) {
      return register.bind(null, state, name, callback, options)
    }, method)()
  }

  return Promise.resolve()
    .then(function () {
      if (!state.registry[name]) {
        return method(options)
      }

      return (state.registry[name]).reduce(function (method, registered) {
        return registered.hook.bind(null, method, options)
      }, method)()
    })
}