Issue #309 - Makes I18n.get raises correctly when receiving invalid iso_code

java/src/main/java/gherkin/I18n.java

@@ -87,6 +87,11 @@ public I18n(String isoCode) {
         this.keywords = new HashMap<String, List<String>>();
 
         Map<String, String> keywordMap = I18N.get(isoCode);
+
+        if (keywordMap == null) {
+            throw new RuntimeException("Language not supported: \"" + isoCode + "\"");
+        }
+
         for (Map.Entry<String, String> entry : keywordMap.entrySet()) {
             List<String> keywordList = Arrays.asList(entry.getValue().split("\\|"));
             if (STEP_KEYWORD_KEYS.contains(entry.getKey())) {

lib/gherkin/i18n.rb

@@ -89,7 +89,7 @@ def languages
     def initialize(iso_code)
       @iso_code = iso_code
       @keywords = LANGUAGES[iso_code]
-      raise "Language not supported: #{iso_code.inspect}" if @iso_code.nil?
+      raise "Language not supported: #{iso_code.inspect}" if @keywords.nil?
       @keywords['grammar_name'] = @keywords['name'].gsub(/\s/, '')
     end
 

spec/gherkin/i18n_spec.rb

@@ -170,6 +170,15 @@ def scan_file(lexer, file)
         ]
       end
 
+      it "should not raise error if iso_code is valid" do
+        expect { Gherkin::I18n.get('pt') }.to_not raise_error
+      end
+
+      it "should raise error if iso_code is not valid" do
+        error_msg = 'Language not supported: "non-valid-iso_code"'
+        expect { Gherkin::I18n.get('non-valid-iso_code') }.to raise_error(error_msg)
+      end
+
       describe 'keywords' do
         it "should have code keywords without space, comma, exclamation or apostrophe" do
           ['Avast', 'Akkor', 'Etantdonné', 'Lorsque', '假設'].each do |code_keyword|