test(#586): can reuse previous concat parts

- Test proving that when you reuse parts from previous concat statement in new concat statement you will get "Maximum callstack size exceeded"

src/parse-result.test.ts

@@ -27,6 +27,18 @@ describe('ember-template-recast', function () {
       expect(print(ast)).toEqual(`<img src="{{this.something}}">`);
     });
 
+    test('can reuse previous concat parts', function () {
+      let template = `<img src="foo {{bar}} baz">`;
+      let original = parse(template);
+      let element = original.body[0] as AST.ElementNode;
+      let attribute = element.attributes[0] as AST.AttrNode;
+      let concat = attribute.value as AST.ConcatStatement;
+
+      let ast = builders.concat([concat.parts[0], concat.parts[1]]);
+
+      expect(print(ast)).toEqual(`<img src="foo {{bar}}">`);
+    });
+
     test('changing an element to a void element does not print closing tag', function () {
       let template = `<div data-foo="{{something}}"></div>`;