java-testinglisted

# Java Testing Skill ## Activation Contract Use this skill for Java tests: unit tests, JUnit/Mockito/AssertJ examples, characterization tests, Golden Master tests, seams, or dependency-breaking. Do not use for non-Java projects, generic strategy, frontend/E2E, performance, security, or refactoring without a testing objective. ## Responsibility Own Java test workflow: detect the local stack, choose the smallest safe technique, create or propose tests, and explain seam/dependency tradeoffs. The caller owns product behavior, dependency approval, and running project commands when validation exists. ## Required Context Before writing tests, inspect or ask for: - Java version, build tool, and test dependencies. - Existing test naming, package layout, assertions, fixtures, and mocking style. - Class under test, observable behavior, collaborators, and failure/edge cases. - For legacy code: change point, test point, hidden dependencies, and whether the seam is for Sensing or Separation. ## Hard Rules - Detect Java level, build tool, JUnit/Mockito versions, assertion style, and dependency management independently. - Preserve the project test stack unless a dependency change is explicitly needed and justified. - Prefer the simplest useful test: pure unit test first, Mockito only across real boundaries, Spring/context tests only when the framework behavior is the subject. - For clean code, test behavior and avoid over-verifying collaborators. - For existing untested or hard-to-