'use strict'

const { func } = require('./symbols')

const objectPredicates = {
  plain: (value) => {
    if (typeof value !== 'object') return false

    const proto = Object.getPrototypeOf(value)
    return proto === null || proto === Object.getPrototypeOf({})
  },
  empty: (value) => Object.keys(value).length === 0,
  nonEmpty: (value) => Object.keys(value).length > 0,

  [func]: {
    is: (fn) => fn,
    instanceOf: (v) => (value) => (value instanceof v)
  }
}

module.exports = {
  predicates: objectPredicates,
  validator: (value) => {
    return typeof value === 'object'
  }
}