Elasticsearch
Elasticsearch is notoriously difficult to test. Its distributed nature, complex query DSL, and stateful index management make traditional unit testing insufficient. This guide covers practical strategies for testing Elasticsearch applications—from spinning up real instances with Testcontainers to validating index mappings and query correctness. Why Elasticsearch Testing Is Hard Unlike
Testing
ActiveMQ Classic provides an embedded broker you can start directly in your test JVM — no Docker, no external process. This makes JUnit tests fast and deterministic. This guide covers testing JMS queues and topics, transactional sending, and dead letter queue behavior using the embedded broker and Spring Boot's
Contract Testing
Spring Cloud Contract is the contract testing framework for Java Spring applications. Unlike Pact (which is consumer-driven), Spring Cloud Contract is provider-driven — the provider defines contracts in the Groovy DSL, generates WireMock stubs from them, and consumers use those stubs in their tests. This guide shows how to