تصنيف البدائل الاختبارية (Test doubles)

في هذا الدرس

name the kinds of test double and pick the right one.

الموضوعات المخطط لها

• A test double is any stand-in for a real collaborator during a test.
• A stub returns canned answers. A mock also records calls so you can verify them.
• A spy wraps a real object and records calls. A fake is a simple working version, such as an in-memory repository.
• Prefer a fake or the real object when it is cheap; use a mock when you must check an interaction or simulate failure.
• The goal is to isolate the code under test, not to remove every dependency.