Validate browse pagination params

src/app/api/browse/pagination.test.ts

@@ -0,0 +1,104 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest';
+import { NextRequest } from 'next/server';
+
+const { mocks } = vi.hoisted(() => ({
+  mocks: {
+    range: vi.fn(),
+    order: vi.fn(),
+    eq: vi.fn(),
+    select: vi.fn(),
+    from: vi.fn(),
+  },
+}));
+
+vi.mock('@/lib/logger', () => {
+  const logger = {
+    child: vi.fn(),
+    debug: vi.fn(),
+    error: vi.fn(),
+    info: vi.fn(),
+    warn: vi.fn(),
+  };
+  logger.child.mockReturnValue(logger);
+
+  return {
+    createLogger: vi.fn(() => logger),
+    generateRequestId: vi.fn(() => 'request-1'),
+  };
+});
+
+vi.mock('@/lib/supabase/client', () => ({
+  getServerClient: vi.fn(() => ({
+    from: mocks.from,
+  })),
+  resetServerClient: vi.fn(),
+}));
+
+vi.mock('@/lib/transforms', () => ({
+  transformTorrents: vi.fn((rows: unknown[]) => rows),
+}));
+
+vi.mock('@/lib/imdb/enrich', () => ({
+  batchEnrichWithImdb: vi.fn(async (rows: unknown[]) => rows),
+}));
+
+import { GET } from './route';
+
+function setupBrowseQuery(): void {
+  mocks.range.mockResolvedValue({ data: [], error: null, count: 0 });
+  mocks.order.mockReturnValue({ range: mocks.range });
+  mocks.eq.mockReturnValue({
+    ilike: vi.fn().mockReturnThis(),
+    eq: mocks.eq,
+    order: mocks.order,
+  });
+  mocks.select.mockReturnValue({ eq: mocks.eq });
+  mocks.from.mockReturnValue({ select: mocks.select });
+}
+
+function createRequest(path: string): NextRequest {
+  return new NextRequest(new URL(path, 'http://localhost:3000'));
+}
+
+describe('GET /api/browse pagination', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    setupBrowseQuery();
+  });
+
+  it('falls back to default pagination when params are malformed', async () => {
+    const response = await GET(
+      createRequest('/api/browse?contentType=movie&limit=bad&offset=wat')
+    );
+    const data = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(mocks.range).toHaveBeenCalledWith(0, 49);
+    expect(data.limit).toBe(50);
+    expect(data.offset).toBe(0);
+  });
+
+  it('rejects negative and fractional pagination params', async () => {
+    const response = await GET(
+      createRequest('/api/browse?contentType=movie&limit=1.5&offset=-10')
+    );
+    const data = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(mocks.range).toHaveBeenCalledWith(0, 49);
+    expect(data.limit).toBe(50);
+    expect(data.offset).toBe(0);
+  });
+
+  it('caps valid limits while preserving valid offsets', async () => {
+    const response = await GET(
+      createRequest('/api/browse?contentType=movie&limit=500&offset=25')
+    );
+    const data = await response.json();
+
+    expect(response.status).toBe(200);
+    expect(mocks.range).toHaveBeenCalledWith(25, 124);
+    expect(data.limit).toBe(100);
+    expect(data.offset).toBe(25);
+  });
+});

src/app/api/browse/route.ts

@@ -44,6 +44,23 @@ const SORT_COLUMN_MAP: Record<SortBy, string> = {
   name: 'name',
 };
 
+function parseBoundedIntegerParam(
+  value: string | null,
+  fallback: number,
+  options: { min: number; max?: number }
+): number {
+  if (value == null || !/^\d+$/.test(value)) {
+    return fallback;
+  }
+
+  const parsed = Number(value);
+  if (!Number.isSafeInteger(parsed) || parsed < options.min) {
+    return fallback;
+  }
+
+  return options.max == null ? parsed : Math.min(parsed, options.max);
+}
+
 /**
  * Check if an error is a network/connection error that warrants client reset
  */
@@ -131,8 +148,8 @@ export async function GET(request: NextRequest): Promise<NextResponse> {
   // Extract pagination
   const limitParam = searchParams.get('limit');
   const offsetParam = searchParams.get('offset');
-  const limit = Math.min(limitParam ? parseInt(limitParam, 10) : 50, 100);
-  const offset = offsetParam ? parseInt(offsetParam, 10) : 0;
+  const limit = parseBoundedIntegerParam(limitParam, 50, { min: 1, max: 100 });
+  const offset = parseBoundedIntegerParam(offsetParam, 0, { min: 0 });
 
   reqLogger.info('GET /api/browse', {
     contentType,