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This skill guides the systematic migration of Java enterprise code from the legacy `javax.*` namespace to the modern `jakarta.*` namespace. It is essential for developers upgrading applications to Jakarta EE 10 or running on Tomcat 11+. The process covers updating imports, modifying dependency coordinates in build files (pom.xml), and adapting web deployment descriptors.

A sophisticated payload bypass technique targeting Java applications. It exploits the silent loss of high 8 bits when 16-bit Java characters are cast or written as 8-bit bytes. This allows attackers to bypass WAF/IDS security measures by making the WAF see harmless Unicode, while the backend service processes the original malicious ASCII byte payload. Ideal for blind SQLi, deserialization RCE, and path traversal. This primitive affects major frameworks like Tomcat, Spring, Jackson, and HttpClient.

This comprehensive playbook details advanced techniques for detecting Prototype Pollution vulnerabilities in JavaScript environments (Node.js and browser). It covers various attack vectors, including using `__proto__` and `constructor.prototype` paths, and provides black-box testing payloads for JSON parsing, query string merging, and deep object assignment. Use this when analyzing applications for potential Remote Code Execution (RCE) or unintended property leakage via object merging sinks.

An expert-level playbook covering non-obvious XSS techniques, advanced payload selection across various sinks (DOM, SVG, HTML attributes, JavaScript), and sophisticated defense bypass strategies. Use this guide for real-world penetration testing, including WAF bypass, CSP bypass, HttpOnly bypass, and XS-Leaks side channel exploitation. It assumes deep knowledge of web vulnerability mechanics.

An internal utility designed for deep investigation of JavaScript or TypeScript stack traces. It analyzes complex runtime errors, providing specific checks for asynchronous boundaries, module resolution issues, JSON parsing failures, and type contract violations. It aids developers by generating minimal reproduction commands and identifying potential patch targets for robust error handling.

This skill generates robust, production-grade End-to-End (E2E) and Component tests using the Cypress framework in JavaScript or TypeScript. It supports local execution and cloud testing environments. Use this skill when you need to write Cypress test cases, set up the Cypress environment, or utilize core commands like `cy.get`, `cy.visit`, and `cy.intercept` for functional validation.

This skill generates comprehensive unit and integration tests using Jest for JavaScript and TypeScript. It supports advanced testing patterns, including deep mocking, asynchronous handling, snapshot testing, and testing React components with Testing Library. Use it when the user needs to thoroughly validate application logic and behavior.

A comprehensive guide and generator for writing robust, production-grade unit and integration tests using JUnit 5 in Java. It covers advanced features like parameterized tests, Mockito mocking, lifecycle management, and nested test structures. Use this skill when you need to write clean, reliable, and highly structured Java test suites.

Bun is a high-performance, all-in-one JavaScript runtime and toolchain. It functions as a runtime, package manager, bundler, and test runner, offering significant speed improvements over traditional Node.js setups. It is ideal for modern, fast-paced development, new projects, and deployment environments like Vercel.

This guide addresses the critical difference between standard Node.js SHA3-256 and the Keccak-256 hash function required by Ethereum. Using the wrong hash function can silently corrupt calculated function selectors, event topics, storage slots, and derived addresses. It provides best practices and code examples for using dedicated libraries (like ethers, viem, web3.js) to ensure correct, Ethereum-compliant hashing in JavaScript and TypeScript environments.

This skill performs a deep technical SEO analysis, diagnosing fundamental website issues related to search engine visibility and performance. It covers optimizing Core Web Vitals, improving crawlability via robots.txt and sitemaps, fixing rendering problems (JavaScript SEO), managing complex redirects, and ensuring optimal site architecture. Use it for comprehensive site audits, migrations, and performance tuning.

This comprehensive guide outlines established best practices for developing robust, high-quality applications using Helidon 4 (SE and MP) in Java 21+. It covers API migrations, project structure, dependency management, and architectural patterns for both MicroProfile and standalone services, ensuring adherence to modern Jakarta EE standards and scalable web development patterns.