test: add test for error boundary

ui/components/app/assets/nfts/nft-grid/nft-grid-item-error-boundary.test.tsx

@@ -0,0 +1,23 @@
+import React, { FC } from 'react';
+import { render } from '@testing-library/react';
+import log from 'loglevel';
+import NFTGridItemErrorBoundary from './nft-grid-item-error-boundary';
+
+describe('NFTGridItemErrorBoundary tests', () => {
+  it('should fallback if grid item crashes', () => {
+    const mockError = jest.spyOn(log, 'error').mockImplementation(jest.fn());
+
+    const MockGridItem: FC = () => {
+      throw new Error('Mock Error');
+    };
+
+    const { container } = render(
+      <NFTGridItemErrorBoundary fallback={() => null}>
+        <MockGridItem />
+      </NFTGridItemErrorBoundary>,
+    );
+
+    expect(container).toBeEmptyDOMElement();
+    expect(mockError).toHaveBeenCalled();
+  });
+});