WeReply: Skill for Claude Code

Refactoring Skill

Systematic code refactoring guidance for improving code quality, maintainability, and design without changing functionality.

Overview

This skill provides refactoring strategies for:

• Extracting methods/functions for better organization
• Removing code duplication (DRY principle)
• Simplifying complex logic and reducing cyclomatic complexity
• Improving naming and readability
• Applying design patterns appropriately
• Reducing technical debt while maintaining functionality

When This Skill Applies

This skill activates when:

• Code is difficult to understand or maintain
• Functions/methods are too long or complex
• Similar code appears in multiple places
• Naming is unclear or inconsistent
• Design patterns could improve structure
• Technical debt needs to be reduced
• Performance optimizations are needed

Refactoring Principles

Core Rules

1. Preserve Functionality: Refactoring should NOT change behavior
2. Small Steps: Make incremental changes with tests between each
3. Test Coverage: Ensure tests pass before and after refactoring
4. Commit Often: Save working state frequently
5. Document Why: Explain reasons for significant changes

Red, Green, Refactor

# 1. Ensure tests pass (GREEN)
cargo test
npm test

# 2. Make small refactoring change
# 3. Run tests again (still GREEN)
cargo test
npm test

# 4. Commit if tests pass
git commit -m "refactor: extract material validation logic"

# Repeat

Common Code Smells & Refactorings

1. Long Method/Function

Smell:

// ❌ 200+ line function doing multiple things
pub async fn create_formula_with_materials(
    &self,
    dto: CreateFormulaDto,
) -> Result<Formula> {
    // Validate name
    if dto.name.is_empty() {
        return Err(anyhow!("Name cannot be empty"));
    }
    if dto.name.len() > 100 {
        return Err(anyhow!("Name too long"));
    }
    // ... 50 more validation lines

    // Check duplicate name
    let exists = sqlx::query_scalar!(
        "SELECT COUNT(*) FROM formulas WHERE name = ?",
        dto.name
    )
    .fetch_one(&self.pool)
    .await?;
    if exists > 0 {
        return Err(anyhow!("Formula already exists"));
    }

    // Validate materials
    for material in &dto.materials {
        if material.proportion < 0.0 || material.proportion > 100.0 {
            return Err(anyhow!("Invalid proportion"));
        }
        // ... 30 more validation lines
    }

    // Insert formula
    // ... 100 more lines
}