Unit Testing

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.

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.

Unit testing Jakarta Bean Validation (@Valid, @NotNull, @Min, @Max, etc.) with custom validators and constraint violations. Test validation logic without Spring context. Use when ensuring data integrity and validation rules are correct.

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 external REST APIs using WireMock to mock HTTP endpoints. Use when testing service integrations with external APIs.

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

Unit tests for mappers and converters (MapStruct, custom mappers). Test object transformation logic in isolation. Use when ensuring correct data transformation between DTOs and domain objects.

Unit tests for REST controllers using MockMvc and @WebMvcTest. Test request/response mapping, validation, and exception handling. Use when testing web layer endpoints in isolation.

Edge case and boundary testing patterns for unit tests. Testing minimum/maximum values, null cases, empty collections, and numeric precision. Pure JUnit 5 unit tests. Use when ensuring code handles limits and special cases correctly.

Parameterized testing patterns with @ParameterizedTest, @ValueSource, @CsvSource. Run single test method with multiple input combinations. Use when testing multiple scenarios with similar logic.

Core Node.js backend patterns for TypeScript applications including async/await error handling, middleware concepts, configuration management, testing strategies, and layered architecture principles. Use when building Node.js backend services, APIs, or microservices.

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

Framework-agnostic HTTP API route testing patterns, authentication strategies, and integration testing best practices. Supports REST APIs with JWT cookie authentication and other common auth patterns.

Generate AI content (images, videos, audio) using YAML pipelines with 28+ models. Run tests, estimate costs, and manage outputs.

MANDATORY for discovering CI commands, features, functions, patterns, or tests in a codebase. Uses progressive disclosure - load specific discovery type as needed.