Add headless test for components

test/specs/grapesjs/headless.js

@@ -1,11 +1,39 @@
 /**
  * @jest-environment node
  */
+let editor;
 
 describe('GrapesJS Headless', () => {
-  test('Can init editor', () => {
+  test('Can init and destroy an editor', () => {
     const editor = grapesjs.init({ headless: true });
     expect(editor).toBeTruthy();
     editor.destroy();
   });
+
+  describe('Headless operations', () => {
+    beforeEach(() => {
+      editor = grapesjs.init({ headless: true });
+    });
+
+    afterEach(() => {
+      editor.destroy();
+    });
+
+    test('Add components', () => {
+      const res = editor.addComponents({
+        attributes: { class: 'cls', test: 'value' },
+        components: { type: 'textnode', content: 'Test' }
+      });
+      expect(res.length).toBe(1);
+      const comp = res[0];
+      const resultHTML = '<div class="cls" test="value">Test</div>';
+      expect(comp.toHTML()).toBe(resultHTML);
+      expect(editor.Selectors.getAll().length).toBe(1); // 1 selector is created
+      expect(editor.Css.getAll().length).toBe(0); // No CSS
+      expect(editor.getHtml()).toBe(resultHTML);
+      expect(editor.getCss()).toBe(editor.getConfig().protectedCss); // same as default
+    });
+
+    test('Add styles', () => {});
+  });
 });