juniorUnit Testing
What is test isolation?
Updated May 6, 2026
Short answer
Test isolation ensures tests run independently without affecting each other.
Deep explanation
Each test should not rely on shared state. This prevents flaky tests and improves reliability.
Real-world example
Resetting database state before each API test.
Common mistakes
- Sharing global variables across tests.
Follow-up questions
- Why is isolation important?
- How to achieve isolation?