Add specs, better error handling

lib/react_on_rails/locales/base.rb

@@ -121,6 +121,8 @@ def generate_translations
           val = flatten(translation[key])
           translations = translations.deep_merge(key => val)
           defaults = defaults.deep_merge(flatten_defaults(val)) if key == default_locale
+        rescue Psych::Exception => e
+          raise ReactOnRails::Error, "Error parsing #{f}: #{e.message}"
         end
         [translations.to_json, defaults.to_json]
       end

spec/react_on_rails/locales_to_js_spec.rb

@@ -98,23 +98,37 @@ module ReactOnRails
     end
 
     describe "with symbols in yaml" do
+      let(:locale_dir) { File.expand_path("fixtures/i18n/locales_symbols", __dir__) }
+
       before do
         ReactOnRails.configure do |config|
-          config.i18n_yml_dir = File.expand_path("fixtures/i18n/locales_symbols", __dir__)
-          config.i18n_yml_safe_load_options = { permitted_classes: [Symbol] }
+          config.i18n_dir = i18n_dir
+          config.i18n_yml_dir = locale_dir
         end
       end
 
       after do
         ReactOnRails.configure do |config|
+          config.i18n_dir = nil
           config.i18n_yml_dir = nil
           config.i18n_yml_safe_load_options = nil
         end
       end
 
-      it "handles locale loading" do
+      it "handles unsafe locale loading" do
+        ReactOnRails.configure do |config|
+          config.i18n_yml_safe_load_options = { permitted_classes: [Symbol] }
+        end
+
         expect { described_class.new }.not_to raise_error
       end
+
+      it "raises error with filename when not permitted" do
+        expect { described_class.new }.to raise_error(
+          ReactOnRails::Error,
+          "Error parsing #{locale_dir}/de.yml: Tried to load unspecified class: Symbol"
+        )
+      end
     end
   end
 end