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GrishaAngelovGH
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expert-code-refactoring

Refactor Java, JavaScript/TypeScript, and React codebases with behavior-preserving small-step changes.

15|2|Updated Jan 8, 2026
Search Tags:#testing#refactoring#react#javascript#java#solid#legacy-code
One-click install
npx skills add https://github.com/GrishaAngelovGH/gemini-cli-agent-skills --skill expert-code-refactoring
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: expert-code-refactoring
Source: https://github.com/GrishaAngelovGH/gemini-cli-agent-skills/tree/main/expert-code-refactoring
Command: npx skills add https://github.com/GrishaAngelovGH/gemini-cli-agent-skills --skill expert-code-refactoring

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This skill reduces technical debt and fragile implementations by guiding safe, incremental refactors that preserve behavior and test coverage across Java, JavaScript/TypeScript, and React codebases.

Core Features & Use Cases

  • Behavior-preserving refactors: Use characterization tests, sprout/wrap methods, and small-step changes to modernize legacy code without breaking existing behavior.
  • Testability & design improvements: Introduce dependency injection, extract pure functions, and apply SOLID patterns to make code easier to test and maintain.
  • Language-targeted guidance: Concrete recommendations for Java (records, streams, immutability), JavaScript/TypeScript (modern syntax, discriminated unions), and React (hooks, state locality).
  • Use Case: Modernize a legacy service by extracting business logic into testable units, adding characterization tests, and incrementally replacing static dependencies with injected interfaces.

Quick Start

Refactor the repository to apply SOLID principles and extract testable units while running and preserving all existing tests after each incremental change.

Frequently Asked Questions about expert-code-refactoring

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I refactor legacy code without breaking existing behavior?▼

Apply SOLID principles during refactoring by introducing dependency injection and extracting pure functions, which isolates business logic and makes modules easier to test and maintain.

Does this refactoring approach support both Java and JavaScript projects?▼

Yes, this refactoring approach supports Java, JavaScript/TypeScript, and React projects, providing targeted guidance like records and streams for Java, and hooks and state locality for React.

How do I improve testability when modernizing a monolithic service?▼

Improve testability by incrementally replacing static dependencies with injected interfaces and extracting business logic into testable units, ensuring existing test suites pass after each change.

What is the best way to apply SOLID principles to an existing codebase?▼

The best way to apply SOLID principles is through incremental modernization, extracting pure functions and introducing dependency injection to reduce technical debt without breaking public APIs.

When should I avoid large-step refactoring on fragile code?▼

Avoid large-step refactoring on fragile code by using small-step changes and characterization tests, which prevent regressions and ensure safe modernization of legacy implementations.

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