Add test for file creation

ui-tests/tests/new-file.spec.ts

@@ -0,0 +1,24 @@
+import { expect, test } from '@jupyterlab/galata';
+
+test.describe('#newFile', () => {
+  test.afterEach(async ({ page }) => {
+    await page.activity.closeAll();
+  });
+
+  test('New file should open with no errors', async ({ page }) => {
+    await page
+      .getByLabel('notebook content')
+      .getByText('New JGIS File')
+      .click();
+
+    const tab = page.getByLabel('notebook content');
+    const sources = page.getByText('Sources', { exact: true });
+    const layers = page.getByText('Layers');
+    const map = page.getByLabel('Map');
+
+    await expect(tab).toBeVisible();
+    await expect(sources).toBeVisible();
+    await expect(layers).toBeVisible();
+    await expect(map).toBeVisible();
+  });
+});