عرض عملي: اختبارات الشرائح مقابل السياق الكامل مع قياس الزمن

خطوة بخطوة

1. Run the controller slice tests and note the time.
2. Write the same check as a @SpringBootTest with @AutoConfigureMockMvc; run and note the time.
3. Run both classes together; show the cached context being reused.
4. Planned mistake: convert every controller test to @SpringBootTest "to be safe"; the suite becomes several times slower. Fix: keep slices; keep one full-context smoke test.
5. Summarize the rule: slice for one layer, full context for wiring and end-to-end.