chore(tests): add is-node-in tests + rename

projects/cdk/utils/dom/test/is-node-in.spec.ts

@@ -0,0 +1,32 @@
+import {isNodeIn} from '../is-node-in';
+
+describe('isNodeIn', () => {
+    it('tag selector', () => {
+        const div = document.createElement('div');
+
+        document.body.appendChild(div);
+
+        expect(isNodeIn(div, 'div')).toEqual(true);
+    });
+
+    it('class selector', () => {
+        const div = document.createElement('div');
+
+        div.classList.add('hello');
+
+        document.body.appendChild(div);
+
+        expect(isNodeIn(div, '.hello')).toEqual(true);
+    });
+
+    it('works with text nodes', () => {
+        const p = document.createElement('p');
+        const textNode = document.createTextNode('hello');
+
+        p.appendChild(textNode);
+
+        document.body.appendChild(p);
+
+        expect(isNodeIn(textNode, 'p')).toEqual(true);
+    });
+});