Journal
Testing Java Agents and Instrumentation with Byte BuddyJava agents operate at a boundary where ordinary application tests are often insufficient. A matcher can look correct while the agent fails to transform a…Performance Testing Java Application Startup Time With Spring BootApplication startup time matters whenever a Java service is restarted, scaled, deployed, or recovered. A slow Spring Boot application can delay a release,…Testing Java File I/O with Temporary Folders and JUnit RulesFile handling often appears simple until a test runs on another operating system, in parallel with other tests, or under a restricted build user. A method that…How to Use Pitest and Mutation Testing in Gradle BuildsA passing test suite can still miss important defects. It may execute a method without checking the result, verify only the happy path, or rely on broad mocks…Writing Tests for Spring Cloud Config Client BehaviourA Spring Cloud Config Client sits between an application and a remote configuration service, so its behaviour can change before the application has handled its…Testing Java Logging Frameworks in Unit TestsLogging is easy to overlook when a Java service has strong functional coverage. A method can return the correct value while emitting the wrong severity,…Mock External APIs with Mountebank for Integration TestsIntegration tests become difficult when an application depends on payment gateways, identity providers, shipping platforms, or other services outside your…Using Pact For Consumer-Driven Contract Testing In JavaMicroservices allow teams to release services independently, but that independence depends on reliable communication between them. A Java service can pass its…Testing REST API Versioning And Backward CompatibilityA REST API rarely changes in isolation. A new mobile release, a partner integration, a reporting dashboard and an internal service may all depend on the same…Testing Java Reflection Frameworks with Focused Unit TestsReflection-based Java frameworks do a great deal of work without showing it directly in application code. They inspect annotations, discover methods, create…