Java Integration testing guidelines

Set up robust integration-test infrastructure for Java services using WireMock to stub outbound HTTP dependencies.

What is covered in this Skill?

• Infrastructure topology detection: scanning imports for HttpClient, feign.*, retrofit2.*, RestTemplate
• Abstract BaseIntegrationTest base class
• WireMockExtension with @RegisterExtension, dynamic port allocation (dynamicPort())
• usingFilesUnderClasspath(wiremock), @BeforeAll + System.setProperty() for coordinate propagation
• WireMock JSON mapping files (bodyFileName referencing wiremock/files/)
• Programmatic stub registration via WireMock DSL
• Per-test stub isolation: register stubs inside each test method
• Fault injection: 503 service unavailable, network latency with withFixedDelay
• Request verification via WIREMOCK.verify
• wiremock-standalone Maven dependency (test scope)
• Anti-patterns: global @BeforeAll stubs, Mockito-mocked HTTP clients, hardcoded ports or URLs

Scope: The reference is organized by examples (good/bad code patterns) for each core area. Apply recommendations based on applicable examples.