refactoring

refactoring is a skill for Claude Code, Codex from nimadorostkar/Claude-Skills-collection. It costs 30 tokens per session (846 once invoked), scanned A, original, MIT.

A set of methods for changing code structure while keeping its observable behavior the same. It includes tests that capture current behavior and small, reversible code changes.

In plain words
What is it for?
Use it to extract functions or classes, break dependencies, simplify legacy code, and verify that tests still pass before and after.
Why use it?
It reduces the risk of breaking working code while making difficult modules easier to test or extend.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to extract functions or classes, break dependencies, simplify legacy code, and verify that tests still pass before and after.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/nimadorostkar/claude-skills-collection/refactoring
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add nimadorostkar/Claude-Skills-collection --skill refactoring
Clone the repo
git clone --depth 1 https://github.com/nimadorostkar/Claude-Skills-collection

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for refactoring

README.md
[![agentmods](https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/refactoring/github.svg)](https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/refactoring)
Your own site
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/refactoring"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/refactoring/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for refactoring

Your own site · 80×15
<a href="https://agentmods.dev/skills/nimadorostkar/claude-skills-collection/refactoring"><img src="https://agentmods.dev/badge/skills/nimadorostkar/claude-skills-collection/refactoring.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 846 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00030 $0.00846
Opus 5 $0.00015 $0.00423
Sonnet 5 $0.00006 $0.00169
Haiku 4.5 $0.00003 $0.00085

Measured 12d ago against content hash 215aec017342, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

refactoring scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 12d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/development/refactoring/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Refactoring

Purpose

Change the structure of code while provably preserving behavior. The defining constraint is that behavior does not change — if it does, it is a rewrite, and it needs different scrutiny.

When to Use

  • Before adding a feature to code that resists the change.
  • When a module has become hard to test.
  • To pay down a specific, identified cost — not to satisfy an aesthetic.
  • After a bug reveals a structural cause.

Capabilities

  • Characterization tests to pin down existing behavior, including its bugs.
  • Standard sequences: extract function, extract class, inline, replace conditional with polymorphism, introduce parameter object.
  • Dependency breaking: seams, adapters, and inversion for untestable code.
  • Incremental strangling of legacy paths behind a stable interface.

Inputs

  • The module to change and the reason for changing it.
  • The existing test suite, and an honest assessment of its coverage.
  • The feature or fix that motivated the refactor, if any.

Outputs

  • Restructured code with identical observable behavior.
  • Tests that passed before and after, unchanged.
  • A commit sequence where each commit is independently green.

Workflow

  1. Justify it — Name the concrete cost the current structure imposes. "It's ugly" is not a cost. "Every new payment method requires editing five files" is.
  2. Pin the behavior — If tests do not cover the code, write characterization tests first: call the code, record what it actually does, assert that. Bugs included.
  3. Refactor in small steps — One mechanical transformation per commit. Run the tests after each.
  4. Do not mix in behavior changes — A refactoring commit and a feature commit must be separate. Reviewers cannot verify both at once.
  5. Stop when the motivating change is easy — Refactoring is preparation, not a destination.

Best Practices

  • Make the change easy, then make the easy change. In that order, in separate commits.
  • Never refactor on a branch that is not fully covered by tests you trust.
  • If the tests need to change, you are not refactoring. Say so.
  • Extract until each function does one thing at one level of abstraction, and no further.
  • Delete dead code aggressively; version control remembers it for you.
  • Resist wholesale rewrites. The existing code encodes years of edge cases you have not thought of.

Read the full file on GitHub · 85 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 12d ago First seen · 85 lines · 30 tokens per session scan A 215aec017342

Subscribe to this mod's changes

refactoring is a skill published in the GitHub repository nimadorostkar/Claude-Skills-collection (26 stars, last pushed 24d ago), licensed MIT. It adds 30 tokens to every session and 846 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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