Testing Cookbook

A collection of small, focused examples for common testing scenarios in Java and Spring Boot.

The goal: show a minimal implementation for each testing approach, including the trade-offs, and provide copy/paste-friendly starting points.

Prerequisites

• Java 25 or above
• Maven 4.x
• Modern Docker Installation

Suggestion: Use sdkman to configure java and maven versions.

Quickstart

#!/usr/bin/env bash

./mvnw clean install

What’s inside

This repo is organized as a multi-project Maven project:

• modules/auto-configuration — Testing custom auto-configuration classes / custom spring starters using ApplicationContextRunner
• modules/bdd — Behavior Driven Development (BDD) tests with Spring, Cucumber, Jupiter, and multiple @CucumberContextConfiguration
• modules/containers — Integration tests with real services via Testcontainers
• modules/embedded-db — In-memory DB testing patterns (e.g., H2, Derby, HSQLDB)
• modules/embedded-kafka — Messaging tests with embedded Kafka
• modules/localstack — AWS integration-style tests locally with LocalStack and Test Containers
• modules/web — HTTP Layer tests via: Mockito, @WebMvcTest, RestTestClient, and TestRestTemplate.

References

• 🐐Spring Boot Testing Documentation