ci: check untracked files after build

dangerfile.ts

@@ -1,27 +1,28 @@
-import { danger, markdown } from 'danger';
+import { danger, markdown, fail } from 'danger';
+import simpleGit, {SimpleGit} from 'simple-git';
+const git: SimpleGit = simpleGit();
 
 const modifiedDefinitionJson = danger.git.fileMatch('src/theme/definition.json');
 
 if (modifiedDefinitionJson.edited) {
   markdown(`
-Hey dear reviewer, I'm the Gravitee.io bot :robot:
+Hey dude, I'm the Gravitee.io bot :robot:
 
 I just want to tell you that \`definition.json\` has been updated in this PR. As this file is used to theme clients' portals you should carefully review it to avoid any regression!
 
 Also, after merging this PR, you should update the \`definition.json\` of [APIM Rest API](https://github.com/gravitee-io/gravitee-management-rest-api).
 `);
 }
 
-const packageJson = danger.git.fileMatch('package.json');
+git.status().then(result => {
+  if(result.modified.length > 0) {
+    fail(`
+Hey dude, I'm the Gravitee.io bot :robot:
 
-if (packageJson.edited) {
-  markdown(`
-Hey dear reviewer, I'm the Gravitee.io bot :robot:
-
-I just want to tell you that \`package.json\` has been updated in this PR. 
-
-Some components are based on third party libraries, for integration into a web component, we extract the css from its libraries as assets.
+There is some untracked files after \`npm run build\` command.
 
-WARNING: When \`codemirror\`, \`highlight.js\` or \`github-markdown-css\` are updated, we must run \`npm run build\` task to update the css.
+Could you run build command locally and fix-it ?
 `);
-}
+
+  }
+});