test: add heading1 test

To ensure the tsconfig.test.json is not causing issues after Button.test.ts was removed

It also allows us to test if the Utrecht Heading1 component is behaving as expected

packages/components-react/src/heading1.test.tsx

@@ -0,0 +1,38 @@
+import { render, screen } from '@testing-library/react';
+import { Heading1 } from '@utrecht/component-library-react';
+import '@testing-library/jest-dom';
+
+describe('Heading1', () => {
+  it('renders a heading role element', () => {
+    render(<Heading1>Hello World</Heading1>);
+
+    const heading1 = screen.getByRole('heading', {
+      name: 'Hello World',
+    });
+
+    expect(heading1).toBeInTheDocument();
+    expect(heading1).toBeVisible();
+  });
+
+  it('renders an HTML h1 element', () => {
+    const { container } = render(<Heading1>Hello World</Heading1>);
+
+    const heading1 = container.querySelector('h1:only-child');
+
+    expect(heading1).toBeInTheDocument();
+  });
+
+  it('renders labels that contain HTML rich text content', () => {
+    const { container } = render(
+      <Heading1>
+        Hello <strong>World</strong>
+      </Heading1>,
+    );
+
+    const heading1 = container.querySelector(':only-child');
+
+    const richText = heading1?.querySelector('strong');
+
+    expect(richText).toBeInTheDocument();
+  });
+});