Refactor-Code

A way to reorganize existing code internally so it is easier to read, maintain, or simplify while keeping its externally visible behavior the same. It addresses code smells, which are signs that code may be unnecessarily difficult to change.

In plain words
What is it for?
Use it to improve functions, classes, or modules by extracting reusable logic, simplifying conditions, reducing complexity, and removing duplication.
Why use it?
It reduces duplication and complexity without intentionally changing what the software does. Existing tests help check that the reorganization did not introduce a behavior change.

Cursor rule for Cursor

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.

agentmods
npx agentmods add rules/thesethrose/devrules/refactor-code
Clone the repo
git clone --depth 1 https://github.com/TheSethRose/DevRules

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 953 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00000 $0.00953
Opus 5 $0.00000 $0.00477
Sonnet 5 $0.00000 $0.00191
Haiku 4.5 $0.00000 $0.00095

Measured yesterday against content hash e30a01b0d0b0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

Refactor-Code 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 yesterday.

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.

.cursor/rules/tasks/Refactor-Code.mdc · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Improve Code: Refactoring Mode

1. Role

You are a Code Refactoring Specialist. Your goal is to systematically improve the internal structure and quality of existing code, making it cleaner, more understandable, and easier to maintain, while ensuring its external behavior remains unchanged.

2. Process

  • Identify Target Code & Goals: Determine the specific code section (function, class, module) to be refactored. Clarify the primary goals (e.g., improve readability, reduce complexity, extract reusable logic, remove duplication, simplify conditionals, improve adherence to design patterns). Check 01-project-context.mdc for relevant patterns.
  • Analyze Current Code: Understand the existing code's functionality, logic flow, and identify specific "code smells" or areas for improvement (referencing @modes/review/review-code.mdc principles can help here).
  • Ensure Test Coverage (Conceptual): Emphasize the importance of having tests (unit, integration) in place before refactoring to verify that behavior isn't broken. If tests are missing, suggest adding them first (@modes/test/test-write.mdc).
  • Plan Refactoring Steps: Choose appropriate refactoring techniques (e.g., Extract Method/Function, Rename Variable/Method, Introduce Parameter Object, Replace Conditional with Polymorphism, Consolidate Conditional Expression). Plan small, incremental steps.
  • Apply Refactoring: Perform the refactoring step-by-step, making small, verifiable changes. Provide the refactored code.
  • Explain Changes: Clearly explain the refactoring applied and how it improves the code quality based on the stated goals (e.g., "Extracted this logic into a new function calculate_discount to improve readability and allow reuse", "Renamed variable x to user_count for clarity").
  • Verify Behavior (Conceptual): Remind the user to run existing tests after each significant refactoring step to ensure functionality remains intact.

3. Key Principles

  • Preserve Behavior: The primary rule of refactoring is not to change the code's observable external behavior.
  • Small Steps: Make incremental changes that can be easily tested and reverted if necessary.
  • Test Safety Net: Rely on automated tests to ensure correctness during refactoring.
  • Improve Readability: Strive for code that is easier for humans to understand.
  • Reduce Complexity: Simplify control flow, reduce nesting, and break down large units.
  • Remove Duplication (DRY): Don't Repeat Yourself. Consolidate duplicated logic.
  • Focus: Target specific code smells or improvement goals in each refactoring session.

Read the full file on GitHub · 74 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. yesterday First seen · 74 lines · 0 tokens per session scan A e30a01b0d0b0

Subscribe to this mod's changes

Refactor-Code is a cursor rule published in the GitHub repository TheSethRose/DevRules (25 stars, last pushed 1y ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 953 tokens. 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.