change i18n directory check (#899)

Source of the issue is that for a directory object, blank? returns true
if the directory is empty.

* change i18n directory check
* added test for i18n_dir = '' in addition to i18n_dir = nil, removed whitespaces, updated changelog
*  if somebody had used "blank" ("") before and they upgrade to this fix, then they probably will be surprised.

CHANGELOG.md

@@ -11,6 +11,7 @@ Changes since last non-beta release.
 - Fix to add missing dependency to run generator spec individually: [PR 962](https://github.com/shakacode/react_on_rails/pull/962) by [tricknotes](https://github.com/tricknotes)
 
 *Please add entries here for your pull requests.*
+- Fixes check for i18n_dir in LocalesToJs returning false when i18n_dir was set. [PR 899](https://github.com/shakacode/react_on_rails/pull/899) by [hakongit](https://github.com/hakongit)
 
 ### [10.0.0] - 2017-10-08
 #### Created

lib/react_on_rails/locales_to_js.rb

@@ -5,7 +5,10 @@
 module ReactOnRails
  class LocalesToJs
  def initialize
- return if i18n_dir.blank?
+ if !i18n_dir.nil? && !File.directory?(i18n_dir)
+ raise "config.i18n_dir is set and it is not a directory. Did you set config.i18n_dir in the react_on_rails initializer?"
+ end
+ return if i18n_yml_dir.nil?
  return unless obsolete?
  @translations, @defaults = generate_translations
  convert

spec/react_on_rails/locales_to_js_spec.rb

@@ -9,6 +9,13 @@ module ReactOnRails
  let(:translations_path) { "#{i18n_dir}/translations.js" }
  let(:default_path) { "#{i18n_dir}/default.js" }
 
+ it "with i18n_dir set to ''" do
+ ReactOnRails.configure do |config|
+ config.i18n_dir = ''
+ end
+ expect { ReactOnRails::LocalesToJs.new }.to raise_error(/config.i18n_dir is set and it is not a directory. Did you set config.i18n_dir in the react_on_rails initializer?/)
+ end
+
  shared_examples "locale to js" do
  context "with obsolete js files" do
  before do