JUnit 5
Modern Java unit testing framework, nested tests, parameterized executions, and dynamic test factory methods.
1 / Java Unit Testing
JUnit 5 was the testing framework for Java projects using Spring Boot. The modern API — nested test classes, parameterized executions, dynamic test factories — provided significantly cleaner test organization compared to JUnit 4's annotation-heavy approach.
2 / Spring Integration Testing
Combined with Spring Boot's test support, JUnit 5 powered integration tests that spun up application contexts, injected mock beans, and verified REST endpoint behavior through MockMvc. In Cairn, integration tests verified cache routing logic, TTL expiration behavior, and Consistent Hashing ring operations under concurrent access.
3 / Parameterized Execution
Parameterized tests were particularly useful for testing hash distribution uniformity across different numbers of virtual nodes and cache key patterns. Each parameter combination generated a separate test case, making distribution analysis systematic rather than ad hoc.