fix(api): classify stats route GitHub errors

Author: kali

app/api/stats/route.test.ts

@@ -158,6 +158,28 @@ describe('GET /api/stats', () => {
     expect(body.error).toBe('GitHub API error');
   });
 
+  it('returns 404 when GitHub reports that the user does not exist', async () => {
+    vi.mocked(fetchGitHubContributions).mockRejectedValue(
+      new Error('GitHub user "missing-user" not found')
+    );
+
+    const response = await GET(makeRequest({ user: 'missing-user' }));
+
+    expect(response.status).toBe(404);
+    const body = await response.json();
+    expect(body.error).toBe('User not found');
+  });
+
+  it('returns 403 when GitHub rate limiting bubbles up from the client', async () => {
+    vi.mocked(fetchGitHubContributions).mockRejectedValue(new Error('API Rate Limit Exceeded'));
+
+    const response = await GET(makeRequest({ user: 'testuser' }));
+
+    expect(response.status).toBe(403);
+    const body = await response.json();
+    expect(body.error).toBe('GitHub API rate limit reached. Please configure GITHUB_TOKEN.');
+  });
+
   it('returns 500 with a generic message for non-Error throws', async () => {
     vi.mocked(fetchGitHubContributions).mockRejectedValue('something went wrong');
     const response = await GET(makeRequest({ user: 'testuser' }));

app/api/stats/route.ts

@@ -71,6 +71,25 @@ export async function GET(request: Request) {
     );
   } catch (error: unknown) {
     const message = error instanceof Error ? error.message : 'Unknown error';
+
+    if (
+      message.toLowerCase().includes('not found') ||
+      message.toLowerCase().includes('could not resolve')
+    ) {
+      return NextResponse.json({ error: 'User not found' }, { status: 404 });
+    }
+
+    if (
+      message.toLowerCase().includes('rate limit') ||
+      message.includes('API limit reached') ||
+      message.includes('status 403')
+    ) {
+      return NextResponse.json(
+        { error: 'GitHub API rate limit reached. Please configure GITHUB_TOKEN.' },
+        { status: 403 }
+      );
+    }
+
     return NextResponse.json({ error: message }, { status: 500 });
   }
 }