add test for sl-include

src/components/include/include.test.ts

@@ -0,0 +1,28 @@
+import { expect, fixture, html, waitUntil } from '@open-wc/testing';
+import sinon from 'sinon';
+
+import '../../../dist/shoelace.js';
+import type SlInclude from './include';
+
+describe('<sl-include>', () => {
+  it('should load content and emit sl-load', async () => {
+    const el = await fixture(html` <sl-include src="https://jsonplaceholder.typicode.com/posts/1"></sl-include> `);
+    const loadHandler = sinon.spy();
+
+    el.addEventListener('sl-load', loadHandler);
+    await waitUntil(() => loadHandler.calledOnce);
+
+    expect(el.innerHTML).to.contain('"id": 1');
+    expect(loadHandler).to.have.been.calledOnce;
+  });
+
+  it('should emit sl-error when content cannot be loaded', async () => {
+    const el = await fixture(html` <sl-include src="https://404"></sl-include> `);
+    const loadHandler = sinon.spy();
+
+    el.addEventListener('sl-error', loadHandler);
+    await waitUntil(() => loadHandler.calledOnce);
+
+    expect(loadHandler).to.have.been.calledOnce;
+  });
+});