PaperclipOrg
Claude Agent Skill · by Github

Spring Boot Testing

Install Spring Boot Testing skill for Claude Code from github/awesome-copilot.

Install
Terminal · npx
$npx skills add https://github.com/obra/superpowers --skill test-driven-development
Works with Paperclip

How Spring Boot Testing fits into a Paperclip company.

Spring Boot Testing drops into any Paperclip agent that handles this kind of work. Assign it to a specialist inside a pre-configured PaperclipOrg company and the skill becomes available on every heartbeat — no prompt engineering, no tool wiring.

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SaaS FactoryPaired

Pre-configured AI company — 18 agents, 18 skills, one-time purchase.

$27$59
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Source file
SKILL.md189 lines
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---name: spring-boot-testingdescription: Expert Spring Boot 4 testing specialist that selects the best Spring Boot testing techniques for your situation with Junit 6 and AssertJ.--- # Spring Boot Testing This skill provides expert guide for testing Spring Boot 4 applications with modern patterns and best practices. ## Core Principles 1. **Test Pyramid**: Unit (fast) > Slice (focused) > Integration (complete)2. **Right Tool**: Use the narrowest slice that gives you confidence3. **AssertJ Style**: Fluent, readable assertions over verbose matchers4. **Modern APIs**: Prefer MockMvcTester and RestTestClient over legacy alternatives ## Which Test Slice? | Scenario | Annotation | Reference ||----------|------------|-----------|| Controller + HTTP semantics | `@WebMvcTest` | [references/webmvctest.md](references/webmvctest.md) || Repository + JPA queries | `@DataJpaTest` | [references/datajpatest.md](references/datajpatest.md) || REST client + external APIs | `@RestClientTest` | [references/restclienttest.md](references/restclienttest.md) || JSON (de)serialization | `@JsonTest` | [references/test-slices-overview.md](references/test-slices-overview.md) || Full application | `@SpringBootTest` | [references/test-slices-overview.md](references/test-slices-overview.md) | ## Test Slices Reference - [references/test-slices-overview.md](references/test-slices-overview.md) - Decision matrix and comparison- [references/webmvctest.md](references/webmvctest.md) - Web layer with MockMvc- [references/datajpatest.md](references/datajpatest.md) - Data layer with Testcontainers- [references/restclienttest.md](references/restclienttest.md) - REST client testing ## Testing Tools Reference - [references/mockmvc-tester.md](references/mockmvc-tester.md) - AssertJ-style MockMvc (3.2+)- [references/mockmvc-classic.md](references/mockmvc-classic.md) - Traditional MockMvc (pre-3.2)- [references/resttestclient.md](references/resttestclient.md) - Spring Boot 4+ REST client- [references/mockitobean.md](references/mockitobean.md) - Mocking dependencies ## Assertion Libraries - [references/assertj-basics.md](references/assertj-basics.md) - Scalars, strings, booleans, dates- [references/assertj-collections.md](references/assertj-collections.md) - Lists, Sets, Maps, arrays ## Testcontainers - [references/testcontainers-jdbc.md](references/testcontainers-jdbc.md) - PostgreSQL, MySQL, etc. ## Test Data Generation - [references/instancio.md](references/instancio.md) - Generate complex test objects (3+ properties) ## Performance & Migration - [references/context-caching.md](references/context-caching.md) - Speed up test suites- [references/sb4-migration.md](references/sb4-migration.md) - Spring Boot 4.0 changes ## Quick Decision Tree ```Testing a controller endpoint?  Yes → @WebMvcTest with MockMvcTester Testing repository queries?  Yes → @DataJpaTest with Testcontainers (real DB) Testing business logic in service?  Yes → Plain JUnit + Mockito (no Spring context) Testing external API client?  Yes → @RestClientTest with MockRestServiceServer Testing JSON mapping?  Yes → @JsonTest Need full integration test?  Yes → @SpringBootTest with minimal context config``` ## Spring Boot 4 Highlights - **RestTestClient**: Modern alternative to TestRestTemplate- **@MockitoBean**: Replaces @MockBean (deprecated)- **MockMvcTester**: AssertJ-style assertions for web tests- **Modular starters**: Technology-specific test starters- **Context pausing**: Automatic pausing of cached contexts (Spring Framework 7) ## Testing Best Practices ### Code Complexity Assessment When a method or class is too complex to test effectively: 1. **Analyze complexity** - If you need more than 5-7 test cases to cover a single method, it's likely too complex2. **Recommend refactoring** - Suggest breaking the code into smaller, focused functions3. **User decision** - If the user agrees to refactor, help identify extraction points4. **Proceed if needed** - If the user decides to continue with the complex code, implement tests despite the difficulty **Example of refactoring recommendation:**```java// Before: Complex method hard to testpublic Order processOrder(OrderRequest request) {  // Validation, discount calculation, payment, inventory, notification...  // 50+ lines of mixed concerns} // After: Refactored into testable unitspublic Order processOrder(OrderRequest request) {  validateOrder(request);  var order = createOrder(request);  applyDiscount(order);  processPayment(order);  updateInventory(order);  sendNotification(order);  return order;}``` ### Avoid Code Redundancy Create helper methods for commonly used objects and mock setup to enhance readability and maintainability. ### Test Organization with @DisplayName Use descriptive display names to clarify test intent: ```java@Test@DisplayName("Should calculate discount for VIP customer")void shouldCalculateDiscountForVip() { } @Test@DisplayName("Should reject order when customer has insufficient credit")void shouldRejectOrderForInsufficientCredit() { }``` ### Test Coverage Order Always structure tests in this order: 1. **Main scenario** - The happy path, most common use case2. **Other paths** - Alternative valid scenarios, edge cases3. **Exceptions/Errors** - Invalid inputs, error conditions, failure modes ### Test Production Scenarios Write tests with real production scenarios in mind. This makes tests more relatable and helps understand code behavior in actual production cases. ### Test Coverage Goals Aim for 80% code coverage as a practical balance between quality and effort. Higher coverage is beneficial but not the only goal. Use Jacoco maven plugin for coverage reporting and tracking.  **Coverage Rules:**- 80+% coverage minimum- Focus on meaningful assertions, not just execution **What to Prioritize:**1. Business-critical paths (payment processing, order validation)2. Complex algorithms (pricing, discount calculations)3. Error handling (exceptions, edge cases)4. Integration points (external APIs, databases) ## Dependencies (Spring Boot 4) ```xml<dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-test</artifactId>  <scope>test</scope></dependency> <!-- For WebMvc tests --><dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-starter-webmvc-test</artifactId>  <scope>test</scope></dependency> <!-- For Testcontainers --><dependency>  <groupId>org.springframework.boot</groupId>  <artifactId>spring-boot-testcontainers</artifactId>  <scope>test</scope></dependency>```