code-verification

Detect implementation defects in changed JavaScript, TypeScript, React, test, and stylesheet code.

264|11|Updated Apr 25, 2026
One-click install
npx skills add https://github.com/coco-research/coco --skill code-verification-coco-research
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: code-verification
Source: https://github.com/coco-research/coco/tree/main/skills/code-verification
Command: npx skills add https://github.com/coco-research/coco --skill code-verification-coco-research

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

This Skill prevents subtle implementation bugs that AI coding assistants often introduce, especially issues that compile cleanly but fail at runtime or during testing.

Core Features & Use Cases

  • TDZ and declaration-order checks: Detects variables, hooks, and functions used before they are declared.
  • Import, reference, and dead-code validation: Verifies exports match imports, renamed symbols are fully updated, and unused code is removed.
  • React and test safety checks: Reviews effect dependencies, cleanup behavior, mock isolation, timer leaks, and query/assertion quality.
  • CSS integrity checks: Confirms JSX class names have matching stylesheet rules and CSS variables are defined correctly.
  • Use case: Run it after a feature change, a refactor, or test edits to catch hidden regressions before marking work complete.

Quick Start

Use the code-verification skill to review the changed files in this branch and report any TDZ, import, dead-code, React, mock, or CSS issues.

Frequently Asked Questions about code-verification

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

FAQPage Schema
How do I catch React effect dependency errors and mock isolation issues before merging code?

To catch React effect dependency errors and mock isolation issues before merging, you need mechanical verification of changed files. This process reviews effect dependencies, cleanup behavior, timer leaks, and query assertions to prevent runtime regressions.

Why does my JavaScript code compile cleanly but fail at runtime with undefined variables?

JavaScript code failing at runtime with undefined variables often involves Temporal Dead Zone (TDZ) and declaration-order issues. Detecting these implementation defects requires checking that variables, hooks, and functions are fully declared before use.

What's the best way to verify import integrity and remove dead code after a refactor?

The best way to verify import integrity and remove dead code after a refactor is to validate reference consistency. This ensures exports match imports, renamed symbols are fully updated, and unused code is automatically detected and removed.

Does CSS class mapping verification check if JSX class names have matching stylesheet rules?

Yes, CSS class mapping verification checks if JSX class names have matching stylesheet rules. It confirms that JSX class names map to existing stylesheet rules and verifies that CSS variables are defined correctly to prevent style breakage.

When do I need to run test safety checks for TypeScript files?

You need to run test safety checks for TypeScript files after feature changes, refactors, or new test coverage. This verifies mock isolation, cleanup behavior, and assertion quality to catch hidden regressions before marking work complete.

Can code verification detect issues in both TypeScript and CSS workflows simultaneously?

Yes, code verification can detect issues in both TypeScript and CSS workflows simultaneously. It applies to JavaScript, TypeScript, React, test, and stylesheet workflows, checking declaration order, import integrity, and CSS variable mapping across all changed files.