test(contributors): add error resilience coverage

Author: chavanGaneshDatta

app/contributors/page.error-resilience.test.tsx

@@ -0,0 +1,114 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { render, screen } from '@testing-library/react';
+import '@testing-library/jest-dom';
+
+type ContributorsClientProps = {
+  contributors: unknown[];
+  totalContributions: number;
+  topContributors: unknown[];
+};
+
+const mockContributorsClient = vi.fn((_props?: ContributorsClientProps) => (
+  <div data-testid="contributors-client">Contributors Client</div>
+));
+
+vi.mock('./ContributorsClient', () => ({
+  default: (props: ContributorsClientProps) => mockContributorsClient(props),
+}));
+
+describe('ContributorsPage Error Resilience', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it('renders successfully under normal conditions', async () => {
+    const { default: ContributorsPage } = await import('./page');
+
+    const page = await ContributorsPage();
+
+    render(page);
+
+    expect(screen.getByTestId('contributors-client')).toBeInTheDocument();
+  });
+
+  it('handles failed contributor fetches without crashing', async () => {
+    const originalFetch = global.fetch;
+
+    global.fetch = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 500,
+      headers: {
+        get: () => null,
+      },
+    } as unknown as Response);
+
+    const { default: ContributorsPage } = await import('./page');
+
+    const page = await ContributorsPage();
+
+    render(page);
+
+    expect(screen.getByTestId('contributors-client')).toBeInTheDocument();
+
+    global.fetch = originalFetch;
+  });
+
+  it('handles rate limit responses gracefully', async () => {
+    const originalFetch = global.fetch;
+
+    global.fetch = vi.fn().mockResolvedValue({
+      ok: false,
+      status: 429,
+      headers: {
+        get: (name: string) => (name === 'x-ratelimit-remaining' ? '0' : null),
+      },
+    } as unknown as Response);
+
+    const { default: ContributorsPage } = await import('./page');
+
+    const page = await ContributorsPage();
+
+    render(page);
+
+    expect(screen.getByTestId('contributors-client')).toBeInTheDocument();
+
+    global.fetch = originalFetch;
+  });
+
+  it('passes empty contributor collections after fetch failures', async () => {
+    const originalFetch = global.fetch;
+
+    global.fetch = vi.fn().mockRejectedValue(new Error('Database unavailable'));
+
+    const { default: ContributorsPage } = await import('./page');
+
+    const page = await ContributorsPage();
+
+    render(page);
+
+    expect(mockContributorsClient).toHaveBeenCalled();
+
+    const props = mockContributorsClient.mock.calls[0][0] as ContributorsClientProps;
+
+    expect(props.contributors).toEqual([]);
+    expect(props.topContributors).toEqual([]);
+
+    global.fetch = originalFetch;
+  });
+
+  it('continues rendering when unexpected service exceptions occur', async () => {
+    const originalFetch = global.fetch;
+
+    global.fetch = vi.fn().mockRejectedValue(new Error('Unexpected runtime error'));
+
+    const { default: ContributorsPage } = await import('./page');
+
+    const page = await ContributorsPage();
+
+    render(page);
+
+    expect(screen.getByTestId('contributors-client')).toBeInTheDocument();
+
+    global.fetch = originalFetch;
+  });
+});