# Dry Refactoring

> Guided workflow to eliminate copy-paste duplication detected by jscpd. Refactor clones using extract function, module, constant, or base class strategies. Use when this capability is needed.

- Skill: `tomevault-io/dry-refactoring` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add tomevault-io/dry-refactoring`
- Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/dry-refactoring/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Productivity
- Author: tomevault-io (https://skillmd.com/u/tomevault-io)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/tomevault-io/dry-refactoring

---


# dry-refactoring

Guided workflow to eliminate copy-paste duplication in source code. Use after running [jscpd](../jscpd/SKILL.md) to detect clones.

## Prerequisites

First, run jscpd to identify duplications:

```bash
npx jscpd --reporters ai <path>
```

See the **[jscpd](../jscpd/SKILL.md)** skill for full option reference.

## Workflow

1. Run jscpd with `--reporters ai` on the target path
2. Parse each clone line to identify the two duplicated locations (file + line range)
3. Read both code fragments from the source files
4. Understand what the duplicated code does
5. Design a refactoring: extract a shared function, class, module, or constant
6. Apply the refactoring — update both locations and all other usages
7. Re-run jscpd to confirm the clone is eliminated
8. Repeat for remaining clones, highest-impact first

## Refactoring Strategies

**Extract function** — when the duplicate is a block of logic:
```ts
// Before: same block in two places
// After: shared function called from both places
```

**Extract module/utility** — when the duplicate spans multiple files in different domains:
```ts
// Move shared logic to a shared utility file and import it
```

**Extract constant or config** — when the duplicate is repeated data or configuration.

**Template/base class** — when the duplicate is structural (e.g., repeated class shape).

Always ensure:
- All call sites are updated, not just the two reported by jscpd
- Tests still pass after refactoring
- The extracted abstraction has a clear, descriptive name

## Tips

- Start with clones that have the highest line count — they have the most impact
- A clone between test files may indicate a missing test helper
- Clones across unrelated modules may signal a missing shared utility
- Use `--min-lines 10` to filter noise and focus on meaningful duplications

---
> Source: [kucherenko/jscpd](https://github.com/kucherenko/jscpd) — distributed by [TomeVault](https://tomevault.io).
<!-- tomevault:4.0:skill_md:2026-06-23 -->