Support JSON as a translation file format.

.gitignore

@@ -7,5 +7,6 @@ pkg
 .bundle
 .rvmrc
 .ruby-version
+.ruby-gemset
 Gemfile.lock
 gemfiles/*.lock

lib/i18n/backend/base.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'yaml'
+require 'json'
 require 'i18n/core_ext/hash'
 require 'i18n/core_ext/kernel/suppress_warnings'
 
@@ -10,7 +11,7 @@ module Base
       include I18n::Backend::Transliterator
 
       # Accepts a list of paths to translation files. Loads translations from
-      # plain Ruby (*.rb) or YAML files (*.yml). See #load_rb and #load_yml
+      # plain Ruby (*.rb), YAML files (*.yml), or JSON files (*.json). See #load_rb, #load_yml, and #load_json
       # for details.
       def load_translations(*filenames)
         filenames = I18n.load_path if filenames.empty?
@@ -236,6 +237,16 @@ def load_yml(filename)
         end
         alias_method :load_yaml, :load_yml
 
+        # Loads a JSON translations file. The data must have locales as
+        # toplevel keys.
+        def load_json(filename)
+          begin
+            JSON.parse(File.read(filename))
+          rescue TypeError, StandardError => e
+            raise InvalidLocaleData.new(filename, e.inspect)
+          end
+        end
+
         def translate_localization_format(locale, object, format, options)
           format.to_s.gsub(/%[aAbBpP]/) do |match|
             case match

test/backend/simple_test.rb

@@ -21,6 +21,10 @@ def setup
     assert_nothing_raised { I18n.backend.load_translations("#{locales_dir}/en.yaml") }
   end
 
+  test "simple load_translations: given a JSON file name with yaml extension does not raise anything" do
+    assert_nothing_raised { I18n.backend.load_translations("#{locales_dir}/en.json") }
+  end
+
   test "simple load_translations: given a Ruby file name it does not raise anything" do
     assert_nothing_raised { I18n.backend.load_translations("#{locales_dir}/en.rb") }
   end
@@ -40,6 +44,11 @@ def setup
     assert_equal({ 'en' => { 'foo' => { 'bar' => 'baz' } } }, data)
   end
 
+  test "simple load_json: loads data from a JSON file" do
+    data = I18n.backend.send(:load_yml, "#{locales_dir}/en.json")
+    assert_equal({ 'en' => { 'foo' => { 'bar' => 'baz' } } }, data)
+  end
+
   test "simple load_translations: loads data from known file formats" do
     I18n.backend = I18n::Backend::Simple.new
     I18n.backend.load_translations("#{locales_dir}/en.rb", "#{locales_dir}/en.yml")

test/test_data/locales/en.json

@@ -0,0 +1,7 @@
+{
+  "en": {
+    "foo": {
+      "bar": "baz"
+    }
+  }
+}