clean-code-mandatory

Mandatory code-organization rules based on clean code and design patterns, with each function kept in the part of the project responsible for it.

In plain words
What is it for?
Use them before writing production code, tests, prototypes, bug fixes, refactors, or features to decide whether logic belongs in a motor, validator, updater, helper, or another focused location.
Why use it?
They prevent mixed responsibilities, duplicated helpers, hard-to-test code, and logic placed in the wrong file.

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/stramp/lost-mines-phandelver/clean-code-mandatory
Clone the repo
git clone --depth 1 https://github.com/Stramp/Lost-Mines-Phandelver

Made for: Cursor.

Per session 2,337 This file is loaded in full into every session.
When invoked 2,337 The same file — it is already loaded in full.
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 $0.02337 $0.02337
Opus 5 $0.01169 $0.01169
Sonnet 5 $0.00467 $0.00467
Haiku 4.5 $0.00234 $0.00234

Measured 2d ago against content hash b83aaf27ceca, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

clean-code-mandatory 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 2d 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.

.cursor/rules/clean-code-mandatory.mdc · 305 lines

How it starts

The opening of the file, as written. The whole thing — 305 lines — stays where its author put it; the contents beside it link to each section on GitHub.

⚠️ CRITICAL RULE - CLEAN CODE AND DESIGN PATTERNS MANDATORY ⚠️

🚨 RULE ZERO - MANDATORY PRE-CODE VALIDATION 🚨

BEFORE writing ANY function, ALWAYS verify:

  1. Can this function be reused? → Goes to Utils/ or Helpers/
  2. Is this function pure (no side effects)? → Can be helper
  3. Is this function in the right place? → Motor only has motor logic, no helpers
  4. Does this function follow Single Responsibility? → One function = one responsibility
  5. Is this function testable in isolation? → If not, refactor

🚨 CRITICAL LOCATION RULE:

  • MOTOR DOES NOT HAVE HELPERS - Motors (*Motor.cpp) only contain motor logic
  • VALIDATOR DOES NOT HAVE HELPERS - Validators only validate
  • UPDATER DOES NOT HAVE HELPERS - Updaters only update
  • HELPERS DO NOT HAVE MOTOR LOGIC - Helpers are pure and reusable functions

If the function can be a helper → CREATE IN Helpers/, NOT in current file

🚨 ABSOLUTE RULE - NO EXCEPTIONS 🚨

ALWAYS, ALWAYS, ALWAYS apply Clean Code and C++ Design Patterns in ALL situations:

  • ✅ Production code
  • ✅ Quick tests
  • ✅ Prototypes
  • ✅ Bug fixes
  • ✅ Refactoring
  • ✅ New features
  • ✅ Any line of code written

NEVER, NEVER, NEVER create code that violates Clean Code or Design Patterns, even if it's:

  • ❌ "Just a quick test"
  • ❌ "I'll fix it later"
  • ❌ "It's temporary"
  • ❌ "It works like this"

MANDATORY Principles

1. Helper/Utility Functions

CRITICAL RULE: Any function that can be reused MUST be in a separate helpers/utilities file.

🚨 ABSOLUTE LOCATION RULE:

  • NEVER create helper inside *Motor.cpp (ex: MulticlassMotor.cpp, PointBuyMotor.cpp)
  • NEVER create helper inside *Validator.cpp (ex: PointBuyValidator.cpp)
  • NEVER create helper inside *Updater.cpp
  • ALWAYS create helper in corresponding *Helpers.h/cpp (ex: MulticlassHelpers.h)

ALWAYS:

  • ✅ Helper functions in Utils/ or Helpers/
  • ✅ Parameterized functions (without internal state dependency)
  • ✅ Pure functions when possible
  • ✅ Functions testable in isolation
  • ✅ Static functions in helper classes/namespaces

Read the full file on GitHub · 305 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. 2d ago First seen · 305 lines · 2,337 tokens per session scan A b83aaf27ceca

Subscribe to this mod's changes

clean-code-mandatory is a cursor rule published in the GitHub repository Stramp/Lost-Mines-Phandelver (2 stars, last pushed 9mo ago), licensed MIT. It adds 2,337 tokens to every session, about $0.0117 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 2026-08-31.