add cdata test for package.json & fix a small bug

tools/cdata-test.js

@@ -131,7 +131,7 @@ describe('Script', () => {
     // run script cdata.js again and wait for it to finish
     await execPromise('node tools/cdata.js');
 
-    checkIfFileWasNewlyCreated(path.join(folderPath, resultFile));
+    await checkIfFileWasNewlyCreated(path.join(folderPath, resultFile));
   }
 
   describe('should build if', () => {
@@ -182,6 +182,10 @@ describe('Script', () => {
     it('cdata.js changes', async () => {
       await testFileModification('tools/cdata.js', 'html_ui.h');
     });
+
+    it('package.json changes', async () => {
+      await testFileModification('package.json', 'html_ui.h');
+    });
   });
 
   describe('should not build if', () => {