Merge pull request #725 from VincentMolinie/fix/null-literal-print

fix(print): fix print for NullLiteral

src/parse-result.test.ts

@@ -1521,6 +1521,24 @@ describe('ember-template-recast', function () {
     });
   });
 
+  describe('NullLiteral', function () {
+    test('it should print correctly', function () {
+      let template = `{{contact-null\n  null\n}}`;
+
+      let ast = parse(template);
+
+      const mustache = ast.body[0] as AST.MustacheStatement;
+      const param = mustache.params[0] as AST.BaseNode;
+
+      // Mark the param as dirty
+      const oldType = param.type;
+      param.type = 'ElementNode';
+      param.type = oldType;
+
+      expect(print(ast)).toEqual(`{{contact-null\n  null\n}}`);
+    });
+  });
+
   test('can remove during traversal by returning `null`', function () {
     let template = stripIndent`
     <p>here is some multiline string</p>

src/parse-result.ts

@@ -1109,11 +1109,12 @@ export default class ParseResult {
         break;
       case 'BooleanLiteral':
       case 'NumberLiteral':
+      case 'NullLiteral':
         {
           let { source } = nodeInfo;
 
           if (dirtyFields.has('value')) {
-            source = ast.value.toString();
+            source = ast.value?.toString() || '';
             dirtyFields.delete('value');
           }