Testing & Security

Write, configure, and run unit + integration tests using project-independent best practices; detect tooling; triage failures/flakes; keep a compact Testing State Capsule.

Comprehensive NestJS framework guide with Drizzle ORM integration. Use when building NestJS applications, setting up APIs, implementing authentication, working with databases, or integrating Drizzle ORM. Covers controllers, providers, modules, middleware, guards, interceptors, testing, microservices, GraphQL, and database patterns.

Unit tests for utility/helper classes and static methods. Test pure functions and helper logic. Use when validating utility code correctness.

Testing strategies for LangChain4j-powered applications. Mock LLM responses, test retrieval chains, and validate AI workflows. Use when testing AI-powered features reliably.

Core patterns and best practices for AWS SDK for Java 2.x. Use when configuring AWS service clients, setting up authentication, managing credentials, configuring timeouts, HTTP clients, or following AWS SDK best practices.

Comprehensive testing patterns for Spring Boot applications including unit, integration, slice, and container-based testing with JUnit 5, Mockito, Testcontainers, and performance optimization. Use when implementing robust test suites for Spring Boot applications.

Unit tests for @ExceptionHandler and @ControllerAdvice for global exception handling. Use when validating error response formatting and HTTP status codes.

Generate comprehensive REST API documentation using SpringDoc OpenAPI 3.0 and Swagger UI in Spring Boot 3.x applications. Use when setting up API documentation, configuring Swagger UI, adding OpenAPI annotations, implementing security documentation, or enhancing REST endpoints with examples and schemas.

Unit tests for scheduled and async tasks using @Scheduled and @Async. Mock task execution and timing. Use when validating asynchronous operations and scheduling behavior.

Configure AWS RDS (Aurora, MySQL, PostgreSQL) with Spring Boot applications. Use when setting up datasources, connection pooling, security, and production-ready database configuration.

Unit tests for @ConfigurationProperties classes with @ConfigurationPropertiesTest. Use when validating application configuration binding and validation.

Unit tests for caching behavior using Spring Cache annotations (@Cacheable, @CachePut, @CacheEvict). Use when validating cache configuration and cache hit/miss scenarios.

Unit tests for Spring Security with @PreAuthorize, @Secured, @RolesAllowed. Test role-based access control and authorization policies. Use when validating security configurations and access control logic.

Guidelines for writing robust CLI end-to-end tests using BATS

Expert in Spring Data Neo4j integration patterns for graph database development. Use when working with Neo4j graph databases, node entities, relationships, Cypher queries, reactive Neo4j operations, or Spring Data Neo4j repositories. Essential for graph data modeling, relationship mapping, custom queries, and Neo4j testing strategies.

Unit tests for JSON serialization/deserialization with Jackson and @JsonTest. Use when validating JSON mapping, custom serializers, and date format handling.

Unit tests for service layer with Mockito. Test business logic in isolation by mocking dependencies. Use when validating service behaviors and business logic without database or external services.

Comprehensive React 19 patterns expert covering Server Components, Actions, use() hook, useOptimistic, useFormStatus, useFormState, React Compiler, concurrent features, Suspense, and modern TypeScript development. Proactively use for any React development, component architecture, state management, performance optimization, or when implementing React 19's latest features.

Integration patterns for LangChain4j with Spring Boot. Auto-configuration, dependency injection, and Spring ecosystem integration. Use when embedding LangChain4j into Spring Boot applications.

Dependency injection workflow for Spring Boot projects covering constructor-first patterns, optional collaborator handling, bean selection, and validation practices.