rust-module-refactor

A set of guidelines for reorganising Rust code into smaller modules while keeping its existing behaviour and public interfaces. Rust is a programming language, and a module is a section of code grouped by responsibility.

In plain words
What is it for?
It supports splitting Rust files, moving tests, limiting internal visibility, and preserving module facades—stable entry points that hide internal changes.
Why use it?
It helps avoid breaking code, tests, or users of a module when splitting large files or changing which details are exposed.

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/williamisnotdefined/rubiks-cube-solver/rust-module-refactor
Clone the repo
git clone --depth 1 https://github.com/williamisnotdefined/rubiks-cube-solver

Made for: Cursor.

Per session 0 Nothing until a file matches its globs; then the whole rule loads.
When invoked 3,331 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 $0.03331
Opus 5 $0.00000 $0.01665
Sonnet 5 $0.00000 $0.00666
Haiku 4.5 $0.00000 $0.00333

Measured yesterday against content hash 245b50bfafa5, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

rust-module-refactor 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/rust-module-refactor.mdc · 300 lines

How it starts

The opening of the file, as written. The whole thing — 300 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Generated from ai/registry.json. Do not edit manually.

Canonical skill: ../../ai/skills/rust-module-refactor.md.

Referenced context:

  • ../../ai/rules/rust-module-refactor-rules.md
  • ../../ai/rules/testing-rules.md
  • ../../ai/architecture/project-architecture.md
  • ../../ai/architecture/rust-module-boundaries.md
  • ../../ai/glossary/cube-terms.md

This file is compiled from canonical AI knowledge files. Edit canonical files under ai, then run npm run ai:sync.

Compiled AI Skill: rust-module-refactor

Canonical Skill: ai/skills/rust-module-refactor.md

Rust Module Refactor

Use this skill when splitting large Rust files, changing mod.rs facades, moving tests, tightening visibility, or improving Rust module boundaries without changing behavior.

Goal

Make Rust code easier to read and maintain by extracting concrete responsibilities while preserving public API, solver behavior, artifact compatibility, and verification coverage.

Read First

  • ai/rules/rust-module-refactor-rules.md
  • ai/rules/testing-rules.md
  • ai/architecture/project-architecture.md
  • ai/architecture/rust-module-boundaries.md
  • ai/glossary/cube-terms.md
  • Use cube-engine when the refactor touches cube state, moves, notation, facelets, or validation.
  • Use solver-search when the refactor touches search, heuristics, pruning tables, or two-phase internals.
  • Use api-boundary when the refactor touches Axum routes, request/response structs, or frontend-facing status contracts.

Workflow

  • Identify the current public API and preserve it with facade modules and pub use before moving implementation details.
  • Split one responsibility at a time: errors, config, result types, parsing, conversion, dispatch, table IO, search traversal, ordering, or tests.
  • Prefer private modules and pub(crate) exports unless an existing caller needs the item.
  • Keep mechanical moves separate from algorithm, heuristic, format, or contract changes.
  • Move tests only when the new location makes the behavior owner clearer.
  • Run targeted tests after each module family, then broader crate tests after a larger boundary is stable.

Read the full file on GitHub · 300 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 · 300 lines · 0 tokens per session scan A 245b50bfafa5

Subscribe to this mod's changes

rust-module-refactor is a cursor rule published in the GitHub repository williamisnotdefined/rubiks-cube-solver (4 stars, last pushed 8d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 3,331 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 2026-08-31.