Merge pull request #159 from smalruby/issues/134_fix_empty_ruby

fixed bug, error empty ruby to code.
(refs #134)

Author: takaokouji

src/lib/ruby-to-blocks-converter/index.js

@@ -77,6 +77,9 @@ class RubyToBlocksConverter {
         try {
             const root = RubyParser.$parse(code);
             let blocks = this._process(root);
+            if (blocks === null || blocks === Opal.nil) {
+                return true;
+            }
             if (!_.isArray(blocks)) {
                 blocks = [blocks];
             }

test/unit/lib/ruby-to-blocks-converter/index.test.js

@@ -26,6 +26,15 @@ describe('RubyToBlocksConverter', () => {
             expect(Object.keys(converter.lists)).toHaveLength(0);
         });
 
+        test('empty', () => {
+            expect(converter.targetCodeToBlocks(target, '')).toBeTruthy();
+            expect(Object.keys(converter.blocks)).toHaveLength(0);
+            expect(converter.errors).toHaveLength(0);
+            expect(Object.keys(converter.variables)).toHaveLength(0);
+            expect(Object.keys(converter.lists)).toHaveLength(0);
+        });
+
+
         describe('top level blocks', () => {
             test('statements', () => {
                 expected = [