test: add component tests for showcase page and cards

packages/app/src/components/showcase/ShowcaseCard.test.tsx

@@ -0,0 +1,59 @@
+import { screen } from '@testing-library/react';
+import { renderInTestApp } from '@backstage/test-utils';
+import { ShowcaseCard } from './ShowcaseCard';
+import { ShowcaseItem, templateShowcaseLink } from './showcaseConfig';
+
+const baseItem: ShowcaseItem = {
+  id: 'template-mcp-server',
+  name: 'MCP Server',
+  description:
+    'Scaffold a Model Context Protocol server that AI assistants connect to for domain-specific tools and context.',
+  category: 'templates',
+  link: templateShowcaseLink('mcp-server'),
+  linkLabel: 'Use template',
+  tags: ['recommended', 'ai', 'mcp', 'github'],
+  isRecommended: true,
+};
+
+describe('ShowcaseCard', () => {
+  it('renders name, description, category label and tags', async () => {
+    await renderInTestApp(<ShowcaseCard item={baseItem} />);
+
+    expect(screen.getByText('MCP Server')).toBeInTheDocument();
+    expect(screen.getByText(/Model Context Protocol server/)).toBeInTheDocument();
+    expect(screen.getByText('Code Templates')).toBeInTheDocument();
+    expect(screen.getByText('ai')).toBeInTheDocument();
+    expect(screen.getByText('mcp')).toBeInTheDocument();
+  });
+
+  it('shows the recommended badge only for recommended items', async () => {
+    const { rerender } = await renderInTestApp(<ShowcaseCard item={baseItem} />);
+    expect(screen.getByText('Recommended')).toBeInTheDocument();
+
+    rerender(<ShowcaseCard item={{ ...baseItem, isRecommended: false }} />);
+    expect(screen.queryByText('Recommended')).not.toBeInTheDocument();
+  });
+
+  it('truncates tags to four', async () => {
+    const item: ShowcaseItem = {
+      ...baseItem,
+      id: 'many-tags',
+      tags: ['one', 'two', 'three', 'four', 'five', 'six'],
+    };
+    await renderInTestApp(<ShowcaseCard item={item} />);
+
+    expect(screen.getByText('four')).toBeInTheDocument();
+    expect(screen.queryByText('five')).not.toBeInTheDocument();
+    expect(screen.queryByText('six')).not.toBeInTheDocument();
+  });
+
+  it('links the action button to the item link with its label', async () => {
+    await renderInTestApp(<ShowcaseCard item={baseItem} />);
+
+    const link = screen.getByRole('link', { name: 'Use template' });
+    expect(link).toHaveAttribute(
+      'href',
+      '/self-service/templates/default/mcp-server',
+    );
+  });
+});

packages/app/src/components/showcase/ShowcasePage.test.tsx

@@ -0,0 +1,73 @@
+import { screen, fireEvent } from '@testing-library/react';
+import { renderInTestApp } from '@backstage/test-utils';
+import { ShowcasePage } from './ShowcasePage';
+import { showcaseItems, countByCategory } from './showcaseConfig';
+
+describe('ShowcasePage', () => {
+  it('renders every item with the total count and category chips', async () => {
+    await renderInTestApp(<ShowcasePage />);
+    const counts = countByCategory(showcaseItems);
+
+    expect(screen.getByText('Plugin Showcase')).toBeInTheDocument();
+    expect(
+      screen.getByText(`${counts.all} items available`),
+    ).toBeInTheDocument();
+    expect(screen.getByText(`All (${counts.all})`)).toBeInTheDocument();
+    expect(
+      screen.getByText(`Code Templates (${counts.templates})`),
+    ).toBeInTheDocument();
+    expect(screen.getByText(`GitHub (${counts.github})`)).toBeInTheDocument();
+    showcaseItems.forEach(item => {
+      expect(
+        document.querySelector(`[data-testid="showcase-card-${item.id}"]`),
+      ).not.toBeNull();
+    });
+  });
+
+  it('filters cards when a category chip is clicked', async () => {
+    await renderInTestApp(<ShowcasePage />);
+
+    fireEvent.click(screen.getByText(/^GitHub \(/));
+
+    const githubItems = showcaseItems.filter(i => i.category === 'github');
+    expect(
+      screen.getByText(`${githubItems.length} items available`),
+    ).toBeInTheDocument();
+    githubItems.forEach(item => {
+      expect(
+        document.querySelector(`[data-testid="showcase-card-${item.id}"]`),
+      ).not.toBeNull();
+    });
+    expect(
+      document.querySelector('[data-testid="showcase-card-template-mcp-server"]'),
+    ).toBeNull();
+  });
+
+  it('filters cards by search term', async () => {
+    await renderInTestApp(<ShowcasePage />);
+
+    fireEvent.change(screen.getByPlaceholderText('Search showcase...'), {
+      target: { value: 'mcp' },
+    });
+
+    expect(
+      document.querySelector('[data-testid="showcase-card-template-mcp-server"]'),
+    ).not.toBeNull();
+    expect(
+      document.querySelector(
+        '[data-testid="showcase-card-template-github-blank-repo"]',
+      ),
+    ).toBeNull();
+  });
+
+  it('shows the empty state when nothing matches', async () => {
+    await renderInTestApp(<ShowcasePage />);
+
+    fireEvent.change(screen.getByPlaceholderText('Search showcase...'), {
+      target: { value: 'zzzz-nothing' },
+    });
+
+    expect(screen.getByText(/No showcase items found/)).toBeInTheDocument();
+    expect(screen.getByText('0 items available')).toBeInTheDocument();
+  });
+});