typeforce/extra.js

Another biased type checking solution for Javascript

var NATIVE = require('./native')
var ERRORS = require('./errors')

function _Buffer (value) {
  return Buffer.isBuffer(value)
}

function Hex (value) {
  return typeof value === 'string' && /^([0-9a-f]{2})+$/i.test(value)
}

function _LengthN (type, length) {
  var name = type.toJSON()

  function Length (value) {
    if (!type(value)) return false
    if (value.length === length) return true

    throw ERRORS.tfCustomError(name + '(Length: ' + length + ')', name + '(Length: ' + value.length + ')')
  }
  Length.toJSON = function () { return name }

  return Length
}

var _ArrayN = _LengthN.bind(null, NATIVE.Array)
var _BufferN = _LengthN.bind(null, _Buffer)
var _HexN = _LengthN.bind(null, Hex)
var _StringN = _LengthN.bind(null, NATIVE.String)

function Range (a, b, f) {
  f = f || NATIVE.Number
  function _range (value, strict) {
    return f(value, strict) && (value > a) && (value < b)
  }
  _range.toJSON = function () {
    return `${f.toJSON()} between [${a}, ${b}]`
  }
  return _range
}

var INT53_MAX = Math.pow(2, 53) - 1

function Finite (value) {
  return typeof value === 'number' && isFinite(value)
}
function Int8 (value) { return ((value << 24) >> 24) === value }
function Int16 (value) { return ((value << 16) >> 16) === value }
function Int32 (value) { return (value | 0) === value }
function Int53 (value) {
  return typeof value === 'number' &&
    value >= -INT53_MAX &&
    value <= INT53_MAX &&
    Math.floor(value) === value
}
function UInt8 (value) { return (value & 0xff) === value }
function UInt16 (value) { return (value & 0xffff) === value }
function UInt32 (value) { return (value >>> 0) === value }
function UInt53 (value) {
  return typeof value === 'number' &&
    value >= 0 &&
    value <= INT53_MAX &&
    Math.floor(value) === value
}

var types = {
  ArrayN: _ArrayN,
  Buffer: _Buffer,
  BufferN: _BufferN,
  Finite: Finite,
  Hex: Hex,
  HexN: _HexN,
  Int8: Int8,
  Int16: Int16,
  Int32: Int32,
  Int53: Int53,
  Range: Range,
  StringN: _StringN,
  UInt8: UInt8,
  UInt16: UInt16,
  UInt32: UInt32,
  UInt53: UInt53
}

for (var typeName in types) {
  types[typeName].toJSON = function (t) {
    return t
  }.bind(null, typeName)
}

module.exports = types