fantasy-validations-flatten-and-chain.js

var R = require('ramda')
var FV = require('fantasy-validations')
var DV = require('data.validation') // folktale

var V = FV

// extend with flatten and chain
V.prototype.flatten = function () {
  return this.f ? this : this.s // TODO use fold
}

V.prototype.chain = function (f) {
  return this.map(f).flatten()
}

// some tests
exports.fantasyValidations = function (t) {
  var s42 = V.of(42)
  console.log('s42 =', s42)

  var s0 = V.Success(42)
  console.log('s0 =', s0)
  var f0 = V.Failure('f0')
  console.log('f0 =', f0)

  var s1 = R.map(x=>x+1)(s0)
  console.log('s1 =', s1)

  t.done()
}

exports.fantasyValidations_concat = function (t) {
  var f0 = V.Failure(['Failure 0'])
  var f1 = V.Failure(['Failure 1'])

  var fs = R.concat(f0, f1)
  console.log('fs =', fs)
  t.done()
}

exports.fantasyValidations_ap = function (t) {
  var mkFoo = (name) => (level) => ({ name: name, level: level })
  var mkFooE = V.Success(mkFoo)

  // example data
  var nameE = V.Success('Erik')
  var levelE = V.Success(9999)

  // aggregate successes
  var s0 = R.ap(mkFooE, nameE)
  console.log('s0 =', s0)

  var s1 = R.ap(s0, levelE)
  console.log('s1 =', s1)

  // aggregate failures
  var f0 = R.ap(mkFooE, V.Failure(['Failure: name']))
  console.log('f0 =', f0)

  var f1 = R.ap(f0, V.Failure(['Failure: level']))
  console.log('f1 =', f1)

  t.done()
}

exports.fantasyValidations_flatten = function (t) {
  var f0 = V.Failure('boo')
  console.log('f0 =', f0)
  console.log('f0.flatten() =', f0.flatten())

  var ss0 = V.of(V.of(42))
  console.log('ss0 =', ss0)
  console.log('ss0.flatten() =', ss0.flatten())

  var sf0 = V.of(V.Failure('boo'))
  console.log('sf0 =', sf0)
  console.log('sf0.flatten() =', sf0.flatten())

  t.done()
}

// join = flatMap = chain
exports.fantasyValidations_chain = function (t) {
  var f = (x) => V.of(x+1)
  var s0 = V.of(42)
  console.log('s0 =', s0)
  var res = R.chain(f, s0)
  console.log('map f s0 =', R.map(f, s0))
  console.log('unnest $ map f s0 =', R.unnest(R.map(f, s0)))
  console.log('res =', res)

  t.done()
}