feat: slugify, rate limit ed env helper con test

tests/rate-limit.test.ts

@@ -0,0 +1,23 @@
+import { describe, it, expect, vi, afterEach } from 'vitest';
+import { rateLimit, _resetBuckets } from '../src/lib/rate-limit';
+
+afterEach(() => { _resetBuckets(); vi.useRealTimers(); });
+
+describe('rateLimit', () => {
+  it('consente fino a max richieste', () => {
+    expect(rateLimit('a', 2, 1000)).toBe(true);
+    expect(rateLimit('a', 2, 1000)).toBe(true);
+    expect(rateLimit('a', 2, 1000)).toBe(false);
+  });
+  it('chiavi indipendenti', () => {
+    expect(rateLimit('a', 1, 1000)).toBe(true);
+    expect(rateLimit('b', 1, 1000)).toBe(true);
+  });
+  it('la finestra scade', () => {
+    vi.useFakeTimers();
+    expect(rateLimit('a', 1, 1000)).toBe(true);
+    expect(rateLimit('a', 1, 1000)).toBe(false);
+    vi.advanceTimersByTime(1100);
+    expect(rateLimit('a', 1, 1000)).toBe(true);
+  });
+});