Add test for file upload

tests/upload.spec.ts

@@ -0,0 +1,20 @@
+import {expect, test} from '@playwright/test';
+import {setupHermeticEnvironment} from './helpers';
+
+test.describe('File upload', () => {
+  test.beforeEach(async ({page, context}) => {
+    await setupHermeticEnvironment(context);
+    await page.goto('/');
+  });
+
+  test('uploads a GEDCOM file and displays the tree', async ({page}) => {
+    // Set the test GEDCOM file to the hidden file input.
+    await page.setInputFiles('#fileInput', 'src/datasource/testdata/test.ged');
+
+    // Assert that we navigated to the view page.
+    await expect(page).toHaveURL(/.*\/view.*/);
+
+    // Verify that the chart content loads properly (e.g. contains the name 'Bonifacy').
+    await expect(page.locator('#content')).toContainText('Bonifacy');
+  });
+});