Add test for cookie custom inspect

lib/__tests__/cookieUtils.spec.ts

@@ -0,0 +1,17 @@
+import { inspect } from 'node:util'
+import { Cookie } from '../cookie/cookie'
+
+describe('Cookie utils', () => {
+  describe('custom inspect', () => {
+    it('should be a readable string', () => {
+      const cookie = new Cookie({
+        key: 'test',
+        value: 'b',
+        maxAge: 60,
+      })
+      expect(inspect(cookie)).toBe(
+        'Cookie="test=b; Max-Age=60; hostOnly=?; aAge=?; cAge=0ms"',
+      )
+    })
+  })
+})