How do I install the Jscpd skill?

Run npx skillmds@latest add tuanductran/jscpd in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Jscpd safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Jscpd?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Jscpd free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

tuanductran (@tuanductran) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Jscpd by tuanductran — Agent Skill

Name: Jscpd
Author: tuanductran

File contents

jscpd

Copy-paste detector for source code. Use this skill to run jscpd against packages/* in this repo and understand its output before handing clones to dry-refactoring.

Not to be confused with packages/hr-skills-build/src/server/validation/detect-duplicates.ts, which detects duplicated HR skill content (skills/hr-*/SKILL.md) at publish time. jscpd here targets TypeScript source code in packages/* only — keep the two concerns separate and never merge their logic.

Quick start

This repo uses Bun, so prefer bunx over npx:

# Scope to the TypeScript packages only — skip skills/ (markdown) and generated output
bunx jscpd@5 packages \
  --format typescript \
  --mode strict \
  --min-lines 3 \
  --min-tokens 20 \
  --reporters console,json,markdown \
  --output duplicate-report \
  --ignore "**/node_modules/**,**/dist/**,**/*.md"

# Compact output optimized for agents
bunx jscpd@5 packages --reporters ai --format typescript

duplicate-report/ is a generated artifact — do not commit it; add it to .gitignore if it isn't already covered.

AI reporter output format

The ai reporter produces compact, token-efficient output:

Clones:
packages/hr-skills-build/src/server/validation/validate.ts:53-59 ~
security.ts:89-94
---
N clones · X% duplication

Same directory: shared path prefix factored out
Different paths: full path shown for both sides

Options used in this repo

Option	Value here	Why
`--format typescript`	scoped to `.ts`	`skills/*/.md` content duplication is handled by `detect-duplicates.ts`, not jscpd
`--mode strict`	exact-match clones	avoids false positives from formatting-only similarity (Biome already normalizes formatting)
`--min-lines 3` / `--min-tokens 20`	low thresholds	this is a small, young codebase; catch clones early before they compound
`--ignore`	`node_modules`, `dist`, `*.md`	matches `.gitignore` / build output conventions

Full option reference: bunx jscpd@5 --help, or the upstream configuration docs.

When to run

Before opening a PR that adds or edits code under packages/hr-skills-build/src/client/**, packages/hr-skills-build/src/server/**, packages/hr-skills-ref/src/client/**, or packages/hr-skills-ref/src/server/**
After a large refactor, to confirm clones were actually eliminated (re-run, don't assume)
Optionally wired into lefthook.yml as a pre-push (not pre-commit — it's slower than biome) step; see CI and hooks for the pattern this repo's lefthook.yml follows for other tools

Tips

Run jscpd against packages/, never against the full repo root — skills/hr-*/SKILL.md files are prompt content, not code, and will produce noisy, irrelevant clones.
Test files (packages/*/test/**) legitimately duplicate describe/it/expect scaffolding — don't chase 100% duplication-free tests. Prioritize src/** clones.
Hand the clone list to dry-refactoring rather than refactoring ad hoc; it enforces "extract, don't just rename."

---name: jscpddescription: Copy-paste detector for the hr-skills TypeScript packages (packages/hr-skills-build, packages/hr-skills-ref). Run jscpd to detect duplicated code and measure duplication percentages before refactoring.---# jscpdCopy-paste detector for source code. Use this skill to run jscpd against `packages/*` in this repo and understand its output before handing clones to [`dry-refactoring`](../dry-refactoring/SKILL.md).> Not to be confused with `packages/hr-skills-build/src/server/validation/detect-duplicates.ts`, which detects duplicated **HR skill content** (`skills/hr-*/SKILL.md`) at publish time. `jscpd` here targets **TypeScript source code** in `packages/*` only — keep the two concerns separate and never merge their logic.## Quick startThis repo uses Bun, so prefer `bunx` over `npx`:```bash# Scope to the TypeScript packages only — skip skills/ (markdown) and generated outputbunx jscpd@5 packages \ --format typescript \ --mode strict \ --min-lines 3 \ --min-tokens 20 \ --reporters console,json,markdown \ --output duplicate-report \ --ignore "**/node_modules/**,**/dist/**,**/*.md"# Compact output optimized for agentsbunx jscpd@5 packages --reporters ai --format typescript````duplicate-report/` is a generated artifact — do not commit it; add it to `.gitignore` if it isn't already covered.## AI reporter output formatThe `ai` reporter produces compact, token-efficient output:```textClones:packages/hr-skills-build/src/server/validation/validate.ts:53-59 ~security.ts:89-94---N clones · X% duplication```- **Same directory**: shared path prefix factored out- **Different paths**: full path shown for both sides## Options used in this repo| Option | Value here | Why ||--------|------------|-----|| `--format typescript` | scoped to `.ts` | `skills/**/*.md` content duplication is handled by `detect-duplicates.ts`, not jscpd || `--mode strict` | exact-match clones | avoids false positives from formatting-only similarity (Biome already normalizes formatting) || `--min-lines 3` / `--min-tokens 20` | low thresholds | this is a small, young codebase; catch clones early before they compound || `--ignore` | `node_modules`, `dist`, `*.md` | matches `.gitignore` / build output conventions |Full option reference: `bunx jscpd@5 --help`, or the [upstream configuration docs](https://jscpd.dev/getting-started/configuration).## When to run- Before opening a PR that adds or edits code under `packages/hr-skills-build/src/client/**`, `packages/hr-skills-build/src/server/**`, `packages/hr-skills-ref/src/client/**`, or `packages/hr-skills-ref/src/server/**`- After a large refactor, to confirm clones were actually eliminated (re-run, don't assume)- Optionally wired into `lefthook.yml` as a pre-push (not pre-commit — it's slower than `biome`) step; see [CI and hooks](https://jscpd.dev/ci-and-hooks) for the pattern this repo's `lefthook.yml` follows for other tools## Tips- Run jscpd against `packages/`, never against the full repo root — `skills/hr-*/SKILL.md` files are prompt content, not code, and will produce noisy, irrelevant clones.- Test files (`packages/*/test/**`) legitimately duplicate `describe`/`it`/`expect` scaffolding — don't chase 100% duplication-free tests. Prioritize `src/**` clones.- Hand the clone list to [`dry-refactoring`](../dry-refactoring/SKILL.md) rather than refactoring ad hoc; it enforces "extract, don't just rename."

Frequently asked questions

Jscpd