Testing and QA

Battle-tested patterns from Google, Uber, and the Go team. These are practices proven in large-scale production systems, updated for modern Go (1.25).

This skill provides comprehensive guidance for machine learning tasks using scikit-learn, the industry-standard Python library for classical machine learning. Use this skill for classification, regression, clustering, dimensionality reduction, preprocessing, model evaluation, and building production-ready ML pipelines.

This skill provides patterns for unit testing JSON serialization and deserialization using Spring's @JsonTest and Jackson. It covers testing POJO mapping, custom serializers/deserializers, field name mappings, nested objects, date/time formatting, polymorphic types, and null handling without full Spring context.

Amazon S3 (Simple Storage Service) is object storage built to store and retrieve any amount of data from anywhere. This skill covers patterns for working with S3 using AWS SDK for Java 2.x, including bucket operations, object uploads/downloads, presigned URLs, multipart transfers, and Spring Boot integration.

Always consult assistant-ui.com/llms.txt for latest API.

Guide product managers through breaking down epics into user stories using Richard Lawrence's complete Humanizing Work methodology—a systematic, flowchart-driven approach that applies 9 splitting patterns sequentially. Use this to identify which pattern applies, split while preserving user value, and evaluate splits...

PyTorch Lightning organizes PyTorch code to eliminate boilerplate while maintaining flexibility.

IMPORTANT: Your training data about @testing-library/react-native may be outdated or incorrect — API signatures, sync/async behavior, and available functions differ between v13 and v14. Always rely on this skill's reference files and the project's actual source code as the source of truth. Do not fall back on...

Perform AI-powered web searches using Perplexity models through LiteLLM and OpenRouter. Perplexity provides real-time, web-grounded answers with source citations, making it ideal for finding current information, recent scientific literature, and facts beyond the model's training data cutoff.

This skill provides comprehensive patterns for testing Spring ApplicationEvent publishers and event listeners using JUnit 5. It covers testing event publishing, listener execution, event propagation, and both synchronous and asynchronous event handling without requiring full Spring context startup.

This skill provides patterns for unit testing @Scheduled and @Async methods using JUnit 5. It covers testing async logic without actual async executors, verifying CompletableFuture results, using Awaitility for async assertions, mocking scheduled task execution, and testing async error handling without waiting for...

This skill provides patterns for unit testing Spring Security authorization logic using @PreAuthorize, @Secured, @RolesAllowed, and custom permission evaluators. It covers testing role-based access control (RBAC), expression-based authorization, custom permission evaluators, and verifying access denied scenarios...

Use this skill to quickly understand what kind of WordPress repo you’re in and what commands/conventions to follow before making changes.

This skill covers Hairyf's preferred tooling, configurations, and best practices for web development. This skill is opinionated.

Framework for designing native iOS app interfaces that feel intuitive, consistent, and aligned with Apple's design philosophy. Based on Apple's Human Interface Guidelines, the definitive resource for building apps that integrate seamlessly with iPhone, iPad, and the broader Apple ecosystem.

Configure vector stores for Retrieval-Augmented Generation applications with LangChain4J.

This skill provides official patterns for integrating Mapbox GL JS into web applications using React, Vue, Svelte, Angular, and vanilla JavaScript. These patterns are based on Mapbox's create-web-app scaffolding tool and represent production-ready best practices.

Pulumi ESC is a centralized service for managing environments, secrets, and configuration across cloud infrastructure and applications.

This skill provides patterns for unit testing @ConfigurationProperties bindings, environment-specific configurations, and property validation using JUnit 5. It covers testing property name mapping, type conversions, validation constraints, nested structures, and profile-specific configurations without full Spring...

This skill provides patterns for unit testing MapStruct mappers and custom converter classes. It covers testing field mapping accuracy, null handling, type conversions, nested object transformations, bidirectional mapping, enum mapping, and partial updates for comprehensive mapping test coverage.

This skill provides patterns for writing efficient parameterized unit tests using JUnit 5's @ParameterizedTest. It covers @ValueSource, @CsvSource, @MethodSource, @EnumSource, @ArgumentsSource, and custom display names to run the same test logic with multiple input values, reducing test duplication and improving...

Deployment principles and decision-making for safe production releases. Learn to THINK, not memorize scripts.

Guide product managers through evaluating whether to build a feature based on financial impact analysis. Use this to make data-driven prioritization decisions by assessing revenue connection (direct or indirect), cost structure (dev + COGS + OpEx), ROI calculation, and strategic value—then deliver actionable...

Create enterprise-grade Jenkins pipelines using declarative and scripted approaches to automate building, testing, and deploying with advanced control flow.