JAVASCRIPT common.js

'use strict'

function isNothing (subject) {
  return (typeof subject === 'undefined') || (subject === null)
}

function isObject (subject) {
  return (typeof subject === 'object') && (subject !== null)
}

function toArray (sequence) {
  if (Array.isArray(sequence)) return sequence
  else if (isNothing(sequence)) return []

  return [sequence]
}

function extend (target, source) {
  if (source) {
    const sourceKeys = Object.keys(source)

    for (let index = 0, length = sourceKeys.length; index < length; index += 1) {
      const key = sourceKeys[index]
      target[key] = source[key]
    }
  }

  return target
}

function repeat (string, count) {
  let result = ''

  for (let cycle = 0; cycle < count; cycle += 1) {
    result += string
  }

  return result
}

function isNegativeZero (number) {
  return (number === 0) && (Number.NEGATIVE_INFINITY === 1 / number)
}

module.exports.isNothing = isNothing
module.exports.isObject = isObject
module.exports.toArray = toArray
module.exports.repeat = repeat
module.exports.isNegativeZero = isNegativeZero
module.exports.extend = extend