Add test cases from #1706

Co-Authored-By: 5saviahv <49443574+5saviahv@users.noreply.github.com>

src/api/traversing.spec.ts

@@ -1238,6 +1238,13 @@ describe('$(...)', () => {
         expect($selection[0]).toBe($fruits[0]);
         expect($selection[1]).toBe($orange[0]);
       });
+      it('is root object preserved', () => {
+        const $selection = $('<div></div>').add('#fruits');
+
+        expect($selection).toHaveLength(2);
+        expect($selection.eq(0).is('div')).toBe(true);
+        expect($selection.eq(1).is($fruits.eq(0))).toBe(true);
+      });
     });
     describe('(selector) matched elements :', () => {
       it('occur before the current selection', () => {

src/cheerio.spec.ts

@@ -270,6 +270,15 @@ describe('cheerio', () => {
       expect(lis).toHaveLength(3);
     });
 
+    it('should preserve root content', () => {
+      const $ = cheerio.load(fruits);
+      // Root should not be overwritten
+      const el = $('<div></div>');
+      expect(Object.is(el, el._root)).toBe(false);
+      // Query has to have results
+      expect($('li', 'ul')).toHaveLength(3);
+    });
+
     it('should allow loading a pre-parsed DOM', () => {
       const dom = parseDOM(food);
       const $ = cheerio.load(dom);