Unit Test

Definition

A test that verifies a single function or module in isolation, without involving external systems.

Example in context

"Unit tests run in milliseconds — no database, no network. Mock all dependencies and test the logic alone."

Related terms

• Integration test — A test verifying how multiple components or services work together, including real database or API calls.
• Mock — A fake object replacing a real dependency in tests, with configurable return values and call verification.
• Stub — A simplified replacement for a real object that returns predefined responses — simpler than a mock, no verification.