/*!
 * make-callback <https://github.com/tunnckoCore/make-callback>
 *
 * Copyright (c) 2015 Charlike Mike Reagent <@tunnckoCore> (http://www.tunnckocore.tk)
 * Released under the MIT license.
 */

/* jshint asi:true */

'use strict'

var fs = require('fs')
var test = require('assertit')
var makeCallback = require('./index')

test('make-callback:', function () {
  test('should throw TypeError "is-async-function expect a function"', function (done) {
    function fixture () {
      makeCallback(12345)
    }

    test.throws(fixture, TypeError)
    test.throws(fixture, /is-async-function expect a function/)
    done()
  })
  test('should throw TypeError "make-callback expect sync function', function (done) {
    function fixture () {
      makeCallback(fs.readFile)
    }

    test.throws(fixture, TypeError)
    test.throws(fixture, /make-callback expect sync function/)
    done()
  })
  test('should throw TypeError "async `fn` expect a callback"', function (done) {
    function fixture () {
      var JSONParseAsync = makeCallback(JSON.parse)
      JSONParseAsync('{"foo":"bar"}')
    }

    test.throws(fixture, TypeError)
    test.throws(fixture, /async `fn` expect a callback/)
    done()
  })
  test('should pass result to callback', function (done) {
    var JSONParseAsync = makeCallback(JSON.parse)

    JSONParseAsync('{"foo":"bar"}', function (err, res) {
      test.ifError(err)
      test.deepEqual(res, {foo: 'bar'})
      done()
    })
  })
  test('should pass error to callback', function (done) {
    var JSONParseAsync = makeCallback(JSON.parse)

    JSONParseAsync('foo bar baz', function (err) {
      test.ok(err)
      test.ifError(!err)
      test.equal(err.message, 'Unexpected token o')
      done()
    })
  })
  test('should pass contents of file to callback (when readFileSync)', function (done) {
    var readFile = makeCallback(fs.readFileSync)

    readFile('./package.json', 'utf8', function (err, res) {
      test.ifError(err)
      test.ok(res.indexOf('tunnckoCore/make-callback') !== -1)
      done()
    })
  })
  test('should pass errors to callback (when readFileSync)', function (done) {
    var readFile = makeCallback(fs.readFileSync)

    readFile('./packdsgfdfgdfgage.json', 'utf8', function (err, res) {
      test.ifError(!err)
      test.equal(err.code, 'ENOENT')
      test.ok(err.message.indexOf('no such file') !== -1)
      done()
    })
  })
  test('should support generators (transform generator to callback)', function (done) {
    function * gen (val) {
      var a = yield 'a'
      var b = yield {b: 'b'}
      var c = yield ['c', 'f']
      var d = yield 123
      return [a, b, c, d, val || 'foobar']
    }

    var genCallback = makeCallback(gen)
    genCallback(function (err, res) {
      test.ifError(err)
      test.equal(res.length, 5)
      test.deepEqual(res, ['a', {b: 'b'}, ['c', 'f'], 123, 'foobar'])
      done()
    })
  })
  test('should handle error in callback if generator throws', function (done) {
    function * gen (val) {
      yield 'a'
      yield val

      throw new Error('yeah')
    }

    var genCallback = makeCallback(gen)
    genCallback(123, function (err, res) {
      test.ifError(!err)
      test.equal(err.message, 'yeah')
      test.equal(res, undefined)
      done()
    })
  })
})